diff --git a/ap/lib/libcurl/curl-7.54.1/m4/curl-functions.m4 b/ap/lib/libcurl/curl-7.54.1/m4/curl-functions.m4
new file mode 100644
index 0000000..dde7fe2
--- /dev/null
+++ b/ap/lib/libcurl/curl-7.54.1/m4/curl-functions.m4
@@ -0,0 +1,7010 @@
+#***************************************************************************
+#                                  _   _ ____  _
+#  Project                     ___| | | |  _ \| |
+#                             / __| | | | |_) | |
+#                            | (__| |_| |  _ <| |___
+#                             \___|\___/|_| \_\_____|
+#
+# Copyright (C) 1998 - 2016, Daniel Stenberg, <daniel@haxx.se>, et al.
+#
+# This software is licensed as described in the file COPYING, which
+# you should have received as part of this distribution. The terms
+# are also available at https://curl.haxx.se/docs/copyright.html.
+#
+# You may opt to use, copy, modify, merge, publish, distribute and/or sell
+# copies of the Software, and permit persons to whom the Software is
+# furnished to do so, under the terms of the COPYING file.
+#
+# This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
+# KIND, either express or implied.
+#
+#***************************************************************************
+
+# File version for 'aclocal' use. Keep it a single number.
+# serial 73
+
+
+dnl CURL_INCLUDES_ARPA_INET
+dnl -------------------------------------------------
+dnl Set up variable with list of headers that must be
+dnl included when arpa/inet.h is to be included.
+
+AC_DEFUN([CURL_INCLUDES_ARPA_INET], [
+curl_includes_arpa_inet="\
+/* includes start */
+#ifdef HAVE_SYS_TYPES_H
+#  include <sys/types.h>
+#endif
+#ifdef HAVE_SYS_SOCKET_H
+#  include <sys/socket.h>
+#endif
+#ifdef HAVE_NETINET_IN_H
+#  include <netinet/in.h>
+#endif
+#ifdef HAVE_ARPA_INET_H
+#  include <arpa/inet.h>
+#endif
+#ifdef HAVE_WINSOCK2_H
+#include <winsock2.h>
+#include <ws2tcpip.h>
+#endif
+/* includes end */"
+  AC_CHECK_HEADERS(
+    sys/types.h sys/socket.h netinet/in.h arpa/inet.h,
+    [], [], [$curl_includes_arpa_inet])
+])
+
+
+dnl CURL_INCLUDES_FCNTL
+dnl -------------------------------------------------
+dnl Set up variable with list of headers that must be
+dnl included when fcntl.h is to be included.
+
+AC_DEFUN([CURL_INCLUDES_FCNTL], [
+curl_includes_fcntl="\
+/* includes start */
+#ifdef HAVE_SYS_TYPES_H
+#  include <sys/types.h>
+#endif
+#ifdef HAVE_UNISTD_H
+#  include <unistd.h>
+#endif
+#ifdef HAVE_FCNTL_H
+#  include <fcntl.h>
+#endif
+/* includes end */"
+  AC_CHECK_HEADERS(
+    sys/types.h unistd.h fcntl.h,
+    [], [], [$curl_includes_fcntl])
+])
+
+
+dnl CURL_INCLUDES_IFADDRS
+dnl -------------------------------------------------
+dnl Set up variable with list of headers that must be
+dnl included when ifaddrs.h is to be included.
+
+AC_DEFUN([CURL_INCLUDES_IFADDRS], [
+curl_includes_ifaddrs="\
+/* includes start */
+#ifdef HAVE_SYS_TYPES_H
+#  include <sys/types.h>
+#endif
+#ifdef HAVE_SYS_SOCKET_H
+#  include <sys/socket.h>
+#endif
+#ifdef HAVE_NETINET_IN_H
+#  include <netinet/in.h>
+#endif
+#ifdef HAVE_IFADDRS_H
+#  include <ifaddrs.h>
+#endif
+/* includes end */"
+  AC_CHECK_HEADERS(
+    sys/types.h sys/socket.h netinet/in.h ifaddrs.h,
+    [], [], [$curl_includes_ifaddrs])
+])
+
+
+dnl CURL_INCLUDES_INTTYPES
+dnl -------------------------------------------------
+dnl Set up variable with list of headers that must be
+dnl included when inttypes.h is to be included.
+
+AC_DEFUN([CURL_INCLUDES_INTTYPES], [
+curl_includes_inttypes="\
+/* includes start */
+#ifdef HAVE_SYS_TYPES_H
+# include <sys/types.h>
+#endif
+#ifdef HAVE_STDINT_H
+# include <stdint.h>
+#endif
+#ifdef HAVE_INTTYPES_H
+# include <inttypes.h>
+#endif
+/* includes end */"
+  case $host_os in
+    irix*)
+      ac_cv_header_stdint_h="no"
+      ;;
+  esac
+  AC_CHECK_HEADERS(
+    sys/types.h stdint.h inttypes.h,
+    [], [], [$curl_includes_inttypes])
+])
+
+
+dnl CURL_INCLUDES_LIBGEN
+dnl -------------------------------------------------
+dnl Set up variable with list of headers that must be
+dnl included when libgen.h is to be included.
+
+AC_DEFUN([CURL_INCLUDES_LIBGEN], [
+curl_includes_libgen="\
+/* includes start */
+#ifdef HAVE_SYS_TYPES_H
+#  include <sys/types.h>
+#endif
+#ifdef HAVE_LIBGEN_H
+#  include <libgen.h>
+#endif
+/* includes end */"
+  AC_CHECK_HEADERS(
+    sys/types.h libgen.h,
+    [], [], [$curl_includes_libgen])
+])
+
+
+dnl CURL_INCLUDES_NETDB
+dnl -------------------------------------------------
+dnl Set up variable with list of headers that must be
+dnl included when netdb.h is to be included.
+
+AC_DEFUN([CURL_INCLUDES_NETDB], [
+curl_includes_netdb="\
+/* includes start */
+#ifdef HAVE_SYS_TYPES_H
+#  include <sys/types.h>
+#endif
+#ifdef HAVE_NETDB_H
+#  include <netdb.h>
+#endif
+/* includes end */"
+  AC_CHECK_HEADERS(
+    sys/types.h netdb.h,
+    [], [], [$curl_includes_netdb])
+])
+
+
+dnl CURL_INCLUDES_POLL
+dnl -------------------------------------------------
+dnl Set up variable with list of headers that must be
+dnl included when poll.h is to be included.
+
+AC_DEFUN([CURL_INCLUDES_POLL], [
+curl_includes_poll="\
+/* includes start */
+#ifdef HAVE_SYS_TYPES_H
+#  include <sys/types.h>
+#endif
+#ifdef HAVE_POLL_H
+#  include <poll.h>
+#endif
+#ifdef HAVE_SYS_POLL_H
+#  include <sys/poll.h>
+#endif
+/* includes end */"
+  AC_CHECK_HEADERS(
+    sys/types.h poll.h sys/poll.h,
+    [], [], [$curl_includes_poll])
+])
+
+
+dnl CURL_INCLUDES_SETJMP
+dnl -------------------------------------------------
+dnl Set up variable with list of headers that must be
+dnl included when setjmp.h is to be included.
+
+AC_DEFUN([CURL_INCLUDES_SETJMP], [
+curl_includes_setjmp="\
+/* includes start */
+#ifdef HAVE_SYS_TYPES_H
+#  include <sys/types.h>
+#endif
+#ifdef HAVE_SETJMP_H
+#  include <setjmp.h>
+#endif
+/* includes end */"
+  AC_CHECK_HEADERS(
+    sys/types.h setjmp.h,
+    [], [], [$curl_includes_setjmp])
+])
+
+
+dnl CURL_INCLUDES_SIGNAL
+dnl -------------------------------------------------
+dnl Set up variable with list of headers that must be
+dnl included when signal.h is to be included.
+
+AC_DEFUN([CURL_INCLUDES_SIGNAL], [
+curl_includes_signal="\
+/* includes start */
+#ifdef HAVE_SYS_TYPES_H
+#  include <sys/types.h>
+#endif
+#ifdef HAVE_SIGNAL_H
+#  include <signal.h>
+#endif
+/* includes end */"
+  AC_CHECK_HEADERS(
+    sys/types.h signal.h,
+    [], [], [$curl_includes_signal])
+])
+
+
+dnl CURL_INCLUDES_SOCKET
+dnl -------------------------------------------------
+dnl Set up variable with list of headers that must be
+dnl included when socket.h is to be included.
+
+AC_DEFUN([CURL_INCLUDES_SOCKET], [
+curl_includes_socket="\
+/* includes start */
+#ifdef HAVE_SYS_TYPES_H
+#  include <sys/types.h>
+#endif
+#ifdef HAVE_SOCKET_H
+#  include <socket.h>
+#endif
+/* includes end */"
+  AC_CHECK_HEADERS(
+    sys/types.h socket.h,
+    [], [], [$curl_includes_socket])
+])
+
+
+dnl CURL_INCLUDES_STDIO
+dnl -------------------------------------------------
+dnl Set up variable with list of headers that must be
+dnl included when stdio.h is to be included.
+
+AC_DEFUN([CURL_INCLUDES_STDIO], [
+curl_includes_stdio="\
+/* includes start */
+#ifdef HAVE_SYS_TYPES_H
+#  include <sys/types.h>
+#endif
+#ifdef HAVE_STDIO_H
+#  include <stdio.h>
+#endif
+/* includes end */"
+  AC_CHECK_HEADERS(
+    sys/types.h stdio.h,
+    [], [], [$curl_includes_stdio])
+])
+
+
+dnl CURL_INCLUDES_STDLIB
+dnl -------------------------------------------------
+dnl Set up variable with list of headers that must be
+dnl included when stdlib.h is to be included.
+
+AC_DEFUN([CURL_INCLUDES_STDLIB], [
+curl_includes_stdlib="\
+/* includes start */
+#ifdef HAVE_SYS_TYPES_H
+#  include <sys/types.h>
+#endif
+#ifdef HAVE_STDLIB_H
+#  include <stdlib.h>
+#endif
+/* includes end */"
+  AC_CHECK_HEADERS(
+    sys/types.h stdlib.h,
+    [], [], [$curl_includes_stdlib])
+])
+
+
+dnl CURL_INCLUDES_STRING
+dnl -------------------------------------------------
+dnl Set up variable with list of headers that must be
+dnl included when string(s).h is to be included.
+
+AC_DEFUN([CURL_INCLUDES_STRING], [
+curl_includes_string="\
+/* includes start */
+#ifdef HAVE_SYS_TYPES_H
+#  include <sys/types.h>
+#endif
+#ifdef HAVE_STRING_H
+#  include <string.h>
+#endif
+#ifdef HAVE_STRINGS_H
+#  include <strings.h>
+#endif
+/* includes end */"
+  AC_CHECK_HEADERS(
+    sys/types.h string.h strings.h,
+    [], [], [$curl_includes_string])
+])
+
+
+dnl CURL_INCLUDES_STROPTS
+dnl -------------------------------------------------
+dnl Set up variable with list of headers that must be
+dnl included when stropts.h is to be included.
+
+AC_DEFUN([CURL_INCLUDES_STROPTS], [
+curl_includes_stropts="\
+/* includes start */
+#ifdef HAVE_SYS_TYPES_H
+#  include <sys/types.h>
+#endif
+#ifdef HAVE_UNISTD_H
+#  include <unistd.h>
+#endif
+#ifdef HAVE_SYS_SOCKET_H
+#  include <sys/socket.h>
+#endif
+#ifdef HAVE_SYS_IOCTL_H
+#  include <sys/ioctl.h>
+#endif
+#ifdef HAVE_STROPTS_H
+#  include <stropts.h>
+#endif
+/* includes end */"
+  AC_CHECK_HEADERS(
+    sys/types.h unistd.h sys/socket.h sys/ioctl.h stropts.h,
+    [], [], [$curl_includes_stropts])
+])
+
+
+dnl CURL_INCLUDES_SYS_SOCKET
+dnl -------------------------------------------------
+dnl Set up variable with list of headers that must be
+dnl included when sys/socket.h is to be included.
+
+AC_DEFUN([CURL_INCLUDES_SYS_SOCKET], [
+curl_includes_sys_socket="\
+/* includes start */
+#ifdef HAVE_SYS_TYPES_H
+#  include <sys/types.h>
+#endif
+#ifdef HAVE_SYS_SOCKET_H
+#  include <sys/socket.h>
+#endif
+/* includes end */"
+  AC_CHECK_HEADERS(
+    sys/types.h sys/socket.h,
+    [], [], [$curl_includes_sys_socket])
+])
+
+
+dnl CURL_INCLUDES_SYS_TYPES
+dnl -------------------------------------------------
+dnl Set up variable with list of headers that must be
+dnl included when sys/types.h is to be included.
+
+AC_DEFUN([CURL_INCLUDES_SYS_TYPES], [
+curl_includes_sys_types="\
+/* includes start */
+#ifdef HAVE_SYS_TYPES_H
+#  include <sys/types.h>
+#endif
+/* includes end */"
+  AC_CHECK_HEADERS(
+    sys/types.h,
+    [], [], [$curl_includes_sys_types])
+])
+
+
+dnl CURL_INCLUDES_SYS_UIO
+dnl -------------------------------------------------
+dnl Set up variable with list of headers that must be
+dnl included when sys/uio.h is to be included.
+
+AC_DEFUN([CURL_INCLUDES_SYS_UIO], [
+curl_includes_sys_uio="\
+/* includes start */
+#ifdef HAVE_SYS_TYPES_H
+#  include <sys/types.h>
+#endif
+#ifdef HAVE_SYS_UIO_H
+#  include <sys/uio.h>
+#endif
+/* includes end */"
+  AC_CHECK_HEADERS(
+    sys/types.h sys/uio.h,
+    [], [], [$curl_includes_sys_uio])
+])
+
+
+dnl CURL_INCLUDES_SYS_XATTR
+dnl -------------------------------------------------
+dnl Set up variable with list of headers that must be
+dnl included when sys/xattr.h is to be included.
+
+AC_DEFUN([CURL_INCLUDES_SYS_XATTR], [
+curl_includes_sys_xattr="\
+/* includes start */
+#ifdef HAVE_SYS_TYPES_H
+#  include <sys/types.h>
+#endif
+#ifdef HAVE_SYS_XATTR_H
+#  include <sys/xattr.h>
+#endif
+/* includes end */"
+  AC_CHECK_HEADERS(
+    sys/types.h sys/xattr.h,
+    [], [], [$curl_includes_sys_xattr])
+])
+
+dnl CURL_INCLUDES_TIME
+dnl -------------------------------------------------
+dnl Set up variable with list of headers that must be
+dnl included when time.h is to be included.
+
+AC_DEFUN([CURL_INCLUDES_TIME], [
+AC_REQUIRE([AC_HEADER_TIME])dnl
+curl_includes_time="\
+/* includes start */
+#ifdef HAVE_SYS_TYPES_H
+#  include <sys/types.h>
+#endif
+#ifdef HAVE_SYS_TIME_H
+#  include <sys/time.h>
+#  ifdef TIME_WITH_SYS_TIME
+#    include <time.h>
+#  endif
+#else
+#  ifdef HAVE_TIME_H
+#    include <time.h>
+#  endif
+#endif
+/* includes end */"
+  AC_CHECK_HEADERS(
+    sys/types.h sys/time.h time.h,
+    [], [], [$curl_includes_time])
+])
+
+
+dnl CURL_INCLUDES_UNISTD
+dnl -------------------------------------------------
+dnl Set up variable with list of headers that must be
+dnl included when unistd.h is to be included.
+
+AC_DEFUN([CURL_INCLUDES_UNISTD], [
+curl_includes_unistd="\
+/* includes start */
+#ifdef HAVE_SYS_TYPES_H
+#  include <sys/types.h>
+#endif
+#ifdef HAVE_UNISTD_H
+#  include <unistd.h>
+#endif
+/* includes end */"
+  AC_CHECK_HEADERS(
+    sys/types.h unistd.h,
+    [], [], [$curl_includes_unistd])
+])
+
+
+dnl CURL_INCLUDES_WINSOCK2
+dnl -------------------------------------------------
+dnl Set up variable with list of headers that must be
+dnl included when winsock(2).h is to be included.
+
+AC_DEFUN([CURL_INCLUDES_WINSOCK2], [
+curl_includes_winsock2="\
+/* includes start */
+#ifdef HAVE_WINDOWS_H
+#  ifndef WIN32_LEAN_AND_MEAN
+#    define WIN32_LEAN_AND_MEAN
+#  endif
+#  include <windows.h>
+#  ifdef HAVE_WINSOCK2_H
+#    include <winsock2.h>
+#  else
+#    ifdef HAVE_WINSOCK_H
+#      include <winsock.h>
+#    endif
+#  endif
+#endif
+/* includes end */"
+  CURL_CHECK_HEADER_WINDOWS
+  CURL_CHECK_HEADER_WINSOCK
+  CURL_CHECK_HEADER_WINSOCK2
+])
+
+
+dnl CURL_INCLUDES_WS2TCPIP
+dnl -------------------------------------------------
+dnl Set up variable with list of headers that must be
+dnl included when ws2tcpip.h is to be included.
+
+AC_DEFUN([CURL_INCLUDES_WS2TCPIP], [
+curl_includes_ws2tcpip="\
+/* includes start */
+#ifdef HAVE_WINDOWS_H
+#  ifndef WIN32_LEAN_AND_MEAN
+#    define WIN32_LEAN_AND_MEAN
+#  endif
+#  include <windows.h>
+#  ifdef HAVE_WINSOCK2_H
+#    include <winsock2.h>
+#    ifdef HAVE_WS2TCPIP_H
+#       include <ws2tcpip.h>
+#    endif
+#  endif
+#endif
+/* includes end */"
+  CURL_CHECK_HEADER_WINDOWS
+  CURL_CHECK_HEADER_WINSOCK2
+  CURL_CHECK_HEADER_WS2TCPIP
+])
+
+
+dnl CURL_PREPROCESS_CALLCONV
+dnl -------------------------------------------------
+dnl Set up variable with a preprocessor block which
+dnl defines function calling convention.
+
+AC_DEFUN([CURL_PREPROCESS_CALLCONV], [
+curl_preprocess_callconv="\
+/* preprocess start */
+#ifdef HAVE_WINDOWS_H
+#  define FUNCALLCONV __stdcall
+#else
+#  define FUNCALLCONV
+#endif
+/* preprocess end */"
+])
+
+
+dnl CURL_CHECK_FUNC_ALARM
+dnl -------------------------------------------------
+dnl Verify if alarm is available, prototyped, and
+dnl can be compiled. If all of these are true, and
+dnl usage has not been previously disallowed with
+dnl shell variable curl_disallow_alarm, then
+dnl HAVE_ALARM will be defined.
+
+AC_DEFUN([CURL_CHECK_FUNC_ALARM], [
+  AC_REQUIRE([CURL_INCLUDES_UNISTD])dnl
+  #
+  tst_links_alarm="unknown"
+  tst_proto_alarm="unknown"
+  tst_compi_alarm="unknown"
+  tst_allow_alarm="unknown"
+  #
+  AC_MSG_CHECKING([if alarm can be linked])
+  AC_LINK_IFELSE([
+    AC_LANG_FUNC_LINK_TRY([alarm])
+  ],[
+    AC_MSG_RESULT([yes])
+    tst_links_alarm="yes"
+  ],[
+    AC_MSG_RESULT([no])
+    tst_links_alarm="no"
+  ])
+  #
+  if test "$tst_links_alarm" = "yes"; then
+    AC_MSG_CHECKING([if alarm is prototyped])
+    AC_EGREP_CPP([alarm],[
+      $curl_includes_unistd
+    ],[
+      AC_MSG_RESULT([yes])
+      tst_proto_alarm="yes"
+    ],[
+      AC_MSG_RESULT([no])
+      tst_proto_alarm="no"
+    ])
+  fi
+  #
+  if test "$tst_proto_alarm" = "yes"; then
+    AC_MSG_CHECKING([if alarm is compilable])
+    AC_COMPILE_IFELSE([
+      AC_LANG_PROGRAM([[
+        $curl_includes_unistd
+      ]],[[
+        if(0 != alarm(0))
+          return 1;
+      ]])
+    ],[
+      AC_MSG_RESULT([yes])
+      tst_compi_alarm="yes"
+    ],[
+      AC_MSG_RESULT([no])
+      tst_compi_alarm="no"
+    ])
+  fi
+  #
+  if test "$tst_compi_alarm" = "yes"; then
+    AC_MSG_CHECKING([if alarm usage allowed])
+    if test "x$curl_disallow_alarm" != "xyes"; then
+      AC_MSG_RESULT([yes])
+      tst_allow_alarm="yes"
+    else
+      AC_MSG_RESULT([no])
+      tst_allow_alarm="no"
+    fi
+  fi
+  #
+  AC_MSG_CHECKING([if alarm might be used])
+  if test "$tst_links_alarm" = "yes" &&
+     test "$tst_proto_alarm" = "yes" &&
+     test "$tst_compi_alarm" = "yes" &&
+     test "$tst_allow_alarm" = "yes"; then
+    AC_MSG_RESULT([yes])
+    AC_DEFINE_UNQUOTED(HAVE_ALARM, 1,
+      [Define to 1 if you have the alarm function.])
+    curl_cv_func_alarm="yes"
+  else
+    AC_MSG_RESULT([no])
+    curl_cv_func_alarm="no"
+  fi
+])
+
+
+dnl CURL_CHECK_FUNC_BASENAME
+dnl -------------------------------------------------
+dnl Verify if basename is available, prototyped, and
+dnl can be compiled. If all of these are true, and
+dnl usage has not been previously disallowed with
+dnl shell variable curl_disallow_basename, then
+dnl HAVE_BASENAME will be defined.
+
+AC_DEFUN([CURL_CHECK_FUNC_BASENAME], [
+  AC_REQUIRE([CURL_INCLUDES_STRING])dnl
+  AC_REQUIRE([CURL_INCLUDES_LIBGEN])dnl
+  AC_REQUIRE([CURL_INCLUDES_UNISTD])dnl
+  #
+  tst_links_basename="unknown"
+  tst_proto_basename="unknown"
+  tst_compi_basename="unknown"
+  tst_allow_basename="unknown"
+  #
+  AC_MSG_CHECKING([if basename can be linked])
+  AC_LINK_IFELSE([
+    AC_LANG_FUNC_LINK_TRY([basename])
+  ],[
+    AC_MSG_RESULT([yes])
+    tst_links_basename="yes"
+  ],[
+    AC_MSG_RESULT([no])
+    tst_links_basename="no"
+  ])
+  #
+  if test "$tst_links_basename" = "yes"; then
+    AC_MSG_CHECKING([if basename is prototyped])
+    AC_EGREP_CPP([basename],[
+      $curl_includes_string
+      $curl_includes_libgen
+      $curl_includes_unistd
+    ],[
+      AC_MSG_RESULT([yes])
+      tst_proto_basename="yes"
+    ],[
+      AC_MSG_RESULT([no])
+      tst_proto_basename="no"
+    ])
+  fi
+  #
+  if test "$tst_proto_basename" = "yes"; then
+    AC_MSG_CHECKING([if basename is compilable])
+    AC_COMPILE_IFELSE([
+      AC_LANG_PROGRAM([[
+        $curl_includes_string
+        $curl_includes_libgen
+        $curl_includes_unistd
+      ]],[[
+        if(0 != basename(0))
+          return 1;
+      ]])
+    ],[
+      AC_MSG_RESULT([yes])
+      tst_compi_basename="yes"
+    ],[
+      AC_MSG_RESULT([no])
+      tst_compi_basename="no"
+    ])
+  fi
+  #
+  if test "$tst_compi_basename" = "yes"; then
+    AC_MSG_CHECKING([if basename usage allowed])
+    if test "x$curl_disallow_basename" != "xyes"; then
+      AC_MSG_RESULT([yes])
+      tst_allow_basename="yes"
+    else
+      AC_MSG_RESULT([no])
+      tst_allow_basename="no"
+    fi
+  fi
+  #
+  AC_MSG_CHECKING([if basename might be used])
+  if test "$tst_links_basename" = "yes" &&
+     test "$tst_proto_basename" = "yes" &&
+     test "$tst_compi_basename" = "yes" &&
+     test "$tst_allow_basename" = "yes"; then
+    AC_MSG_RESULT([yes])
+    AC_DEFINE_UNQUOTED(HAVE_BASENAME, 1,
+      [Define to 1 if you have the basename function.])
+    curl_cv_func_basename="yes"
+  else
+    AC_MSG_RESULT([no])
+    curl_cv_func_basename="no"
+  fi
+])
+
+
+dnl CURL_CHECK_FUNC_CLOSESOCKET
+dnl -------------------------------------------------
+dnl Verify if closesocket is available, prototyped, and
+dnl can be compiled. If all of these are true, and
+dnl usage has not been previously disallowed with
+dnl shell variable curl_disallow_closesocket, then
+dnl HAVE_CLOSESOCKET will be defined.
+
+AC_DEFUN([CURL_CHECK_FUNC_CLOSESOCKET], [
+  AC_REQUIRE([CURL_INCLUDES_WINSOCK2])dnl
+  AC_REQUIRE([CURL_INCLUDES_SOCKET])dnl
+  #
+  tst_links_closesocket="unknown"
+  tst_proto_closesocket="unknown"
+  tst_compi_closesocket="unknown"
+  tst_allow_closesocket="unknown"
+  #
+  AC_MSG_CHECKING([if closesocket can be linked])
+  AC_LINK_IFELSE([
+    AC_LANG_PROGRAM([[
+      $curl_includes_winsock2
+      $curl_includes_socket
+    ]],[[
+      if(0 != closesocket(0))
+        return 1;
+    ]])
+  ],[
+    AC_MSG_RESULT([yes])
+    tst_links_closesocket="yes"
+  ],[
+    AC_MSG_RESULT([no])
+    tst_links_closesocket="no"
+  ])
+  #
+  if test "$tst_links_closesocket" = "yes"; then
+    AC_MSG_CHECKING([if closesocket is prototyped])
+    AC_EGREP_CPP([closesocket],[
+      $curl_includes_winsock2
+      $curl_includes_socket
+    ],[
+      AC_MSG_RESULT([yes])
+      tst_proto_closesocket="yes"
+    ],[
+      AC_MSG_RESULT([no])
+      tst_proto_closesocket="no"
+    ])
+  fi
+  #
+  if test "$tst_proto_closesocket" = "yes"; then
+    AC_MSG_CHECKING([if closesocket is compilable])
+    AC_COMPILE_IFELSE([
+      AC_LANG_PROGRAM([[
+        $curl_includes_winsock2
+        $curl_includes_socket
+      ]],[[
+        if(0 != closesocket(0))
+          return 1;
+      ]])
+    ],[
+      AC_MSG_RESULT([yes])
+      tst_compi_closesocket="yes"
+    ],[
+      AC_MSG_RESULT([no])
+      tst_compi_closesocket="no"
+    ])
+  fi
+  #
+  if test "$tst_compi_closesocket" = "yes"; then
+    AC_MSG_CHECKING([if closesocket usage allowed])
+    if test "x$curl_disallow_closesocket" != "xyes"; then
+      AC_MSG_RESULT([yes])
+      tst_allow_closesocket="yes"
+    else
+      AC_MSG_RESULT([no])
+      tst_allow_closesocket="no"
+    fi
+  fi
+  #
+  AC_MSG_CHECKING([if closesocket might be used])
+  if test "$tst_links_closesocket" = "yes" &&
+     test "$tst_proto_closesocket" = "yes" &&
+     test "$tst_compi_closesocket" = "yes" &&
+     test "$tst_allow_closesocket" = "yes"; then
+    AC_MSG_RESULT([yes])
+    AC_DEFINE_UNQUOTED(HAVE_CLOSESOCKET, 1,
+      [Define to 1 if you have the closesocket function.])
+    curl_cv_func_closesocket="yes"
+  else
+    AC_MSG_RESULT([no])
+    curl_cv_func_closesocket="no"
+  fi
+])
+
+
+dnl CURL_CHECK_FUNC_CLOSESOCKET_CAMEL
+dnl -------------------------------------------------
+dnl Verify if CloseSocket is available, prototyped, and
+dnl can be compiled. If all of these are true, and
+dnl usage has not been previously disallowed with
+dnl shell variable curl_disallow_closesocket_camel,
+dnl then HAVE_CLOSESOCKET_CAMEL will be defined.
+
+AC_DEFUN([CURL_CHECK_FUNC_CLOSESOCKET_CAMEL], [
+  AC_REQUIRE([CURL_INCLUDES_SYS_SOCKET])dnl
+  #
+  tst_links_closesocket_camel="unknown"
+  tst_proto_closesocket_camel="unknown"
+  tst_compi_closesocket_camel="unknown"
+  tst_allow_closesocket_camel="unknown"
+  #
+  AC_MSG_CHECKING([if CloseSocket can be linked])
+  AC_LINK_IFELSE([
+    AC_LANG_PROGRAM([[
+      $curl_includes_sys_socket
+    ]],[[
+      if(0 != CloseSocket(0))
+        return 1;
+    ]])
+  ],[
+    AC_MSG_RESULT([yes])
+    tst_links_closesocket_camel="yes"
+  ],[
+    AC_MSG_RESULT([no])
+    tst_links_closesocket_camel="no"
+  ])
+  #
+  if test "$tst_links_closesocket_camel" = "yes"; then
+    AC_MSG_CHECKING([if CloseSocket is prototyped])
+    AC_EGREP_CPP([CloseSocket],[
+      $curl_includes_sys_socket
+    ],[
+      AC_MSG_RESULT([yes])
+      tst_proto_closesocket_camel="yes"
+    ],[
+      AC_MSG_RESULT([no])
+      tst_proto_closesocket_camel="no"
+    ])
+  fi
+  #
+  if test "$tst_proto_closesocket_camel" = "yes"; then
+    AC_MSG_CHECKING([if CloseSocket is compilable])
+    AC_COMPILE_IFELSE([
+      AC_LANG_PROGRAM([[
+        $curl_includes_sys_socket
+      ]],[[
+        if(0 != CloseSocket(0))
+          return 1;
+      ]])
+    ],[
+      AC_MSG_RESULT([yes])
+      tst_compi_closesocket_camel="yes"
+    ],[
+      AC_MSG_RESULT([no])
+      tst_compi_closesocket_camel="no"
+    ])
+  fi
+  #
+  if test "$tst_compi_closesocket_camel" = "yes"; then
+    AC_MSG_CHECKING([if CloseSocket usage allowed])
+    if test "x$curl_disallow_closesocket_camel" != "xyes"; then
+      AC_MSG_RESULT([yes])
+      tst_allow_closesocket_camel="yes"
+    else
+      AC_MSG_RESULT([no])
+      tst_allow_closesocket_camel="no"
+    fi
+  fi
+  #
+  AC_MSG_CHECKING([if CloseSocket might be used])
+  if test "$tst_links_closesocket_camel" = "yes" &&
+     test "$tst_proto_closesocket_camel" = "yes" &&
+     test "$tst_compi_closesocket_camel" = "yes" &&
+     test "$tst_allow_closesocket_camel" = "yes"; then
+    AC_MSG_RESULT([yes])
+    AC_DEFINE_UNQUOTED(HAVE_CLOSESOCKET_CAMEL, 1,
+      [Define to 1 if you have the CloseSocket camel case function.])
+    curl_cv_func_closesocket_camel="yes"
+  else
+    AC_MSG_RESULT([no])
+    curl_cv_func_closesocket_camel="no"
+  fi
+])
+
+
+dnl CURL_CHECK_FUNC_CONNECT
+dnl -------------------------------------------------
+dnl Verify if connect is available, prototyped, and
+dnl can be compiled. If all of these are true, and
+dnl usage has not been previously disallowed with
+dnl shell variable curl_disallow_connect, then
+dnl HAVE_CONNECT will be defined.
+
+AC_DEFUN([CURL_CHECK_FUNC_CONNECT], [
+  AC_REQUIRE([CURL_INCLUDES_WINSOCK2])dnl
+  AC_REQUIRE([CURL_INCLUDES_SYS_SOCKET])dnl
+  AC_REQUIRE([CURL_INCLUDES_SOCKET])dnl
+  #
+  tst_links_connect="unknown"
+  tst_proto_connect="unknown"
+  tst_compi_connect="unknown"
+  tst_allow_connect="unknown"
+  #
+  AC_MSG_CHECKING([if connect can be linked])
+  AC_LINK_IFELSE([
+    AC_LANG_PROGRAM([[
+      $curl_includes_winsock2
+      $curl_includes_sys_socket
+      $curl_includes_socket
+    ]],[[
+      if(0 != connect(0, 0, 0))
+        return 1;
+    ]])
+  ],[
+    AC_MSG_RESULT([yes])
+    tst_links_connect="yes"
+  ],[
+    AC_MSG_RESULT([no])
+    tst_links_connect="no"
+  ])
+  #
+  if test "$tst_links_connect" = "yes"; then
+    AC_MSG_CHECKING([if connect is prototyped])
+    AC_EGREP_CPP([connect],[
+      $curl_includes_winsock2
+      $curl_includes_sys_socket
+      $curl_includes_socket
+    ],[
+      AC_MSG_RESULT([yes])
+      tst_proto_connect="yes"
+    ],[
+      AC_MSG_RESULT([no])
+      tst_proto_connect="no"
+    ])
+  fi
+  #
+  if test "$tst_proto_connect" = "yes"; then
+    AC_MSG_CHECKING([if connect is compilable])
+    AC_COMPILE_IFELSE([
+      AC_LANG_PROGRAM([[
+        $curl_includes_winsock2
+        $curl_includes_sys_socket
+        $curl_includes_socket
+      ]],[[
+        if(0 != connect(0, 0, 0))
+          return 1;
+      ]])
+    ],[
+      AC_MSG_RESULT([yes])
+      tst_compi_connect="yes"
+    ],[
+      AC_MSG_RESULT([no])
+      tst_compi_connect="no"
+    ])
+  fi
+  #
+  if test "$tst_compi_connect" = "yes"; then
+    AC_MSG_CHECKING([if connect usage allowed])
+    if test "x$curl_disallow_connect" != "xyes"; then
+      AC_MSG_RESULT([yes])
+      tst_allow_connect="yes"
+    else
+      AC_MSG_RESULT([no])
+      tst_allow_connect="no"
+    fi
+  fi
+  #
+  AC_MSG_CHECKING([if connect might be used])
+  if test "$tst_links_connect" = "yes" &&
+     test "$tst_proto_connect" = "yes" &&
+     test "$tst_compi_connect" = "yes" &&
+     test "$tst_allow_connect" = "yes"; then
+    AC_MSG_RESULT([yes])
+    AC_DEFINE_UNQUOTED(HAVE_CONNECT, 1,
+      [Define to 1 if you have the connect function.])
+    curl_cv_func_connect="yes"
+  else
+    AC_MSG_RESULT([no])
+    curl_cv_func_connect="no"
+  fi
+])
+
+
+dnl CURL_CHECK_FUNC_FCNTL
+dnl -------------------------------------------------
+dnl Verify if fcntl is available, prototyped, and
+dnl can be compiled. If all of these are true, and
+dnl usage has not been previously disallowed with
+dnl shell variable curl_disallow_fcntl, then
+dnl HAVE_FCNTL will be defined.
+
+AC_DEFUN([CURL_CHECK_FUNC_FCNTL], [
+  AC_REQUIRE([CURL_INCLUDES_FCNTL])dnl
+  #
+  tst_links_fcntl="unknown"
+  tst_proto_fcntl="unknown"
+  tst_compi_fcntl="unknown"
+  tst_allow_fcntl="unknown"
+  #
+  AC_MSG_CHECKING([if fcntl can be linked])
+  AC_LINK_IFELSE([
+    AC_LANG_FUNC_LINK_TRY([fcntl])
+  ],[
+    AC_MSG_RESULT([yes])
+    tst_links_fcntl="yes"
+  ],[
+    AC_MSG_RESULT([no])
+    tst_links_fcntl="no"
+  ])
+  #
+  if test "$tst_links_fcntl" = "yes"; then
+    AC_MSG_CHECKING([if fcntl is prototyped])
+    AC_EGREP_CPP([fcntl],[
+      $curl_includes_fcntl
+    ],[
+      AC_MSG_RESULT([yes])
+      tst_proto_fcntl="yes"
+    ],[
+      AC_MSG_RESULT([no])
+      tst_proto_fcntl="no"
+    ])
+  fi
+  #
+  if test "$tst_proto_fcntl" = "yes"; then
+    AC_MSG_CHECKING([if fcntl is compilable])
+    AC_COMPILE_IFELSE([
+      AC_LANG_PROGRAM([[
+        $curl_includes_fcntl
+      ]],[[
+        if(0 != fcntl(0, 0, 0))
+          return 1;
+      ]])
+    ],[
+      AC_MSG_RESULT([yes])
+      tst_compi_fcntl="yes"
+    ],[
+      AC_MSG_RESULT([no])
+      tst_compi_fcntl="no"
+    ])
+  fi
+  #
+  if test "$tst_compi_fcntl" = "yes"; then
+    AC_MSG_CHECKING([if fcntl usage allowed])
+    if test "x$curl_disallow_fcntl" != "xyes"; then
+      AC_MSG_RESULT([yes])
+      tst_allow_fcntl="yes"
+    else
+      AC_MSG_RESULT([no])
+      tst_allow_fcntl="no"
+    fi
+  fi
+  #
+  AC_MSG_CHECKING([if fcntl might be used])
+  if test "$tst_links_fcntl" = "yes" &&
+     test "$tst_proto_fcntl" = "yes" &&
+     test "$tst_compi_fcntl" = "yes" &&
+     test "$tst_allow_fcntl" = "yes"; then
+    AC_MSG_RESULT([yes])
+    AC_DEFINE_UNQUOTED(HAVE_FCNTL, 1,
+      [Define to 1 if you have the fcntl function.])
+    curl_cv_func_fcntl="yes"
+    CURL_CHECK_FUNC_FCNTL_O_NONBLOCK
+  else
+    AC_MSG_RESULT([no])
+    curl_cv_func_fcntl="no"
+  fi
+])
+
+
+dnl CURL_CHECK_FUNC_FCNTL_O_NONBLOCK
+dnl -------------------------------------------------
+dnl Verify if fcntl with status flag O_NONBLOCK is
+dnl available, can be compiled, and seems to work. If
+dnl all of these are true, then HAVE_FCNTL_O_NONBLOCK
+dnl will be defined.
+
+AC_DEFUN([CURL_CHECK_FUNC_FCNTL_O_NONBLOCK], [
+  #
+  tst_compi_fcntl_o_nonblock="unknown"
+  tst_allow_fcntl_o_nonblock="unknown"
+  #
+  case $host_os in
+    sunos4* | aix3* | beos*)
+      dnl O_NONBLOCK does not work on these platforms
+      curl_disallow_fcntl_o_nonblock="yes"
+      ;;
+  esac
+  #
+  if test "$curl_cv_func_fcntl" = "yes"; then
+    AC_MSG_CHECKING([if fcntl O_NONBLOCK is compilable])
+    AC_COMPILE_IFELSE([
+      AC_LANG_PROGRAM([[
+        $curl_includes_fcntl
+      ]],[[
+        int flags = 0;
+        if(0 != fcntl(0, F_SETFL, flags | O_NONBLOCK))
+          return 1;
+      ]])
+    ],[
+      AC_MSG_RESULT([yes])
+      tst_compi_fcntl_o_nonblock="yes"
+    ],[
+      AC_MSG_RESULT([no])
+      tst_compi_fcntl_o_nonblock="no"
+    ])
+  fi
+  #
+  if test "$tst_compi_fcntl_o_nonblock" = "yes"; then
+    AC_MSG_CHECKING([if fcntl O_NONBLOCK usage allowed])
+    if test "x$curl_disallow_fcntl_o_nonblock" != "xyes"; then
+      AC_MSG_RESULT([yes])
+      tst_allow_fcntl_o_nonblock="yes"
+    else
+      AC_MSG_RESULT([no])
+      tst_allow_fcntl_o_nonblock="no"
+    fi
+  fi
+  #
+  AC_MSG_CHECKING([if fcntl O_NONBLOCK might be used])
+  if test "$tst_compi_fcntl_o_nonblock" = "yes" &&
+     test "$tst_allow_fcntl_o_nonblock" = "yes"; then
+    AC_MSG_RESULT([yes])
+    AC_DEFINE_UNQUOTED(HAVE_FCNTL_O_NONBLOCK, 1,
+      [Define to 1 if you have a working fcntl O_NONBLOCK function.])
+    curl_cv_func_fcntl_o_nonblock="yes"
+  else
+    AC_MSG_RESULT([no])
+    curl_cv_func_fcntl_o_nonblock="no"
+  fi
+])
+
+
+dnl CURL_CHECK_FUNC_FDOPEN
+dnl -------------------------------------------------
+dnl Verify if fdopen is available, prototyped, and
+dnl can be compiled. If all of these are true, and
+dnl usage has not been previously disallowed with
+dnl shell variable curl_disallow_fdopen, then
+dnl HAVE_FDOPEN will be defined.
+
+AC_DEFUN([CURL_CHECK_FUNC_FDOPEN], [
+  AC_REQUIRE([CURL_INCLUDES_STDIO])dnl
+  #
+  tst_links_fdopen="unknown"
+  tst_proto_fdopen="unknown"
+  tst_compi_fdopen="unknown"
+  tst_allow_fdopen="unknown"
+  #
+  AC_MSG_CHECKING([if fdopen can be linked])
+  AC_LINK_IFELSE([
+    AC_LANG_FUNC_LINK_TRY([fdopen])
+  ],[
+    AC_MSG_RESULT([yes])
+    tst_links_fdopen="yes"
+  ],[
+    AC_MSG_RESULT([no])
+    tst_links_fdopen="no"
+  ])
+  #
+  if test "$tst_links_fdopen" = "yes"; then
+    AC_MSG_CHECKING([if fdopen is prototyped])
+    AC_EGREP_CPP([fdopen],[
+      $curl_includes_stdio
+    ],[
+      AC_MSG_RESULT([yes])
+      tst_proto_fdopen="yes"
+    ],[
+      AC_MSG_RESULT([no])
+      tst_proto_fdopen="no"
+    ])
+  fi
+  #
+  if test "$tst_proto_fdopen" = "yes"; then
+    AC_MSG_CHECKING([if fdopen is compilable])
+    AC_COMPILE_IFELSE([
+      AC_LANG_PROGRAM([[
+        $curl_includes_stdio
+      ]],[[
+        if(0 != fdopen(0, 0))
+          return 1;
+      ]])
+    ],[
+      AC_MSG_RESULT([yes])
+      tst_compi_fdopen="yes"
+    ],[
+      AC_MSG_RESULT([no])
+      tst_compi_fdopen="no"
+    ])
+  fi
+  #
+  if test "$tst_compi_fdopen" = "yes"; then
+    AC_MSG_CHECKING([if fdopen usage allowed])
+    if test "x$curl_disallow_fdopen" != "xyes"; then
+      AC_MSG_RESULT([yes])
+      tst_allow_fdopen="yes"
+    else
+      AC_MSG_RESULT([no])
+      tst_allow_fdopen="no"
+    fi
+  fi
+  #
+  AC_MSG_CHECKING([if fdopen might be used])
+  if test "$tst_links_fdopen" = "yes" &&
+     test "$tst_proto_fdopen" = "yes" &&
+     test "$tst_compi_fdopen" = "yes" &&
+     test "$tst_allow_fdopen" = "yes"; then
+    AC_MSG_RESULT([yes])
+    AC_DEFINE_UNQUOTED(HAVE_FDOPEN, 1,
+      [Define to 1 if you have the fdopen function.])
+    curl_cv_func_fdopen="yes"
+  else
+    AC_MSG_RESULT([no])
+    curl_cv_func_fdopen="no"
+  fi
+])
+
+
+dnl CURL_CHECK_FUNC_FGETXATTR
+dnl -------------------------------------------------
+dnl Verify if fgetxattr is available, prototyped, and
+dnl can be compiled. If all of these are true, and
+dnl usage has not been previously disallowed with
+dnl shell variable curl_disallow_fgetxattr, then
+dnl HAVE_FGETXATTR will be defined.
+
+AC_DEFUN([CURL_CHECK_FUNC_FGETXATTR], [
+  AC_REQUIRE([CURL_INCLUDES_SYS_XATTR])dnl
+  #
+  tst_links_fgetxattr="unknown"
+  tst_proto_fgetxattr="unknown"
+  tst_compi_fgetxattr="unknown"
+  tst_allow_fgetxattr="unknown"
+  tst_nargs_fgetxattr="unknown"
+  #
+  AC_MSG_CHECKING([if fgetxattr can be linked])
+  AC_LINK_IFELSE([
+    AC_LANG_FUNC_LINK_TRY([fgetxattr])
+  ],[
+    AC_MSG_RESULT([yes])
+    tst_links_fgetxattr="yes"
+  ],[
+    AC_MSG_RESULT([no])
+    tst_links_fgetxattr="no"
+  ])
+  #
+  if test "$tst_links_fgetxattr" = "yes"; then
+    AC_MSG_CHECKING([if fgetxattr is prototyped])
+    AC_EGREP_CPP([fgetxattr],[
+      $curl_includes_sys_xattr
+    ],[
+      AC_MSG_RESULT([yes])
+      tst_proto_fgetxattr="yes"
+    ],[
+      AC_MSG_RESULT([no])
+      tst_proto_fgetxattr="no"
+    ])
+  fi
+  #
+  if test "$tst_proto_fgetxattr" = "yes"; then
+    if test "$tst_nargs_fgetxattr" = "unknown"; then
+      AC_MSG_CHECKING([if fgetxattr takes 4 args.])
+      AC_COMPILE_IFELSE([
+        AC_LANG_PROGRAM([[
+          $curl_includes_sys_xattr
+        ]],[[
+          if(0 != fgetxattr(0, 0, 0, 0))
+            return 1;
+        ]])
+      ],[
+        AC_MSG_RESULT([yes])
+        tst_compi_fgetxattr="yes"
+        tst_nargs_fgetxattr="4"
+      ],[
+        AC_MSG_RESULT([no])
+        tst_compi_fgetxattr="no"
+      ])
+    fi
+    if test "$tst_nargs_fgetxattr" = "unknown"; then
+      AC_MSG_CHECKING([if fgetxattr takes 6 args.])
+      AC_COMPILE_IFELSE([
+        AC_LANG_PROGRAM([[
+          $curl_includes_sys_xattr
+        ]],[[
+          if(0 != fgetxattr(0, 0, 0, 0, 0, 0))
+            return 1;
+        ]])
+      ],[
+        AC_MSG_RESULT([yes])
+        tst_compi_fgetxattr="yes"
+        tst_nargs_fgetxattr="6"
+      ],[
+        AC_MSG_RESULT([no])
+        tst_compi_fgetxattr="no"
+      ])
+    fi
+    AC_MSG_CHECKING([if fgetxattr is compilable])
+    if test "$tst_compi_fgetxattr" = "yes"; then
+      AC_MSG_RESULT([yes])
+    else
+      AC_MSG_RESULT([no])
+    fi
+  fi
+  #
+  if test "$tst_compi_fgetxattr" = "yes"; then
+    AC_MSG_CHECKING([if fgetxattr usage allowed])
+    if test "x$curl_disallow_fgetxattr" != "xyes"; then
+      AC_MSG_RESULT([yes])
+      tst_allow_fgetxattr="yes"
+    else
+      AC_MSG_RESULT([no])
+      tst_allow_fgetxattr="no"
+    fi
+  fi
+  #
+  AC_MSG_CHECKING([if fgetxattr might be used])
+  if test "$tst_links_fgetxattr" = "yes" &&
+     test "$tst_proto_fgetxattr" = "yes" &&
+     test "$tst_compi_fgetxattr" = "yes" &&
+     test "$tst_allow_fgetxattr" = "yes"; then
+    AC_MSG_RESULT([yes])
+    AC_DEFINE_UNQUOTED(HAVE_FGETXATTR, 1,
+      [Define to 1 if you have the fgetxattr function.])
+    dnl AC_DEFINE_UNQUOTED(FGETXATTR_ARGS, $tst_nargs_fgetxattr,
+    dnl   [Specifies the number of arguments to fgetxattr])
+    #
+    if test "$tst_nargs_fgetxattr" -eq "4"; then
+      AC_DEFINE(HAVE_FGETXATTR_4, 1, [fgetxattr() takes 4 args])
+    elif test "$tst_nargs_fgetxattr" -eq "6"; then
+      AC_DEFINE(HAVE_FGETXATTR_6, 1, [fgetxattr() takes 6 args])
+    fi
+    #
+    curl_cv_func_fgetxattr="yes"
+  else
+    AC_MSG_RESULT([no])
+    curl_cv_func_fgetxattr="no"
+  fi
+])
+
+
+dnl CURL_CHECK_FUNC_FLISTXATTR
+dnl -------------------------------------------------
+dnl Verify if flistxattr is available, prototyped, and
+dnl can be compiled. If all of these are true, and
+dnl usage has not been previously disallowed with
+dnl shell variable curl_disallow_flistxattr, then
+dnl HAVE_FLISTXATTR will be defined.
+
+AC_DEFUN([CURL_CHECK_FUNC_FLISTXATTR], [
+  AC_REQUIRE([CURL_INCLUDES_SYS_XATTR])dnl
+  #
+  tst_links_flistxattr="unknown"
+  tst_proto_flistxattr="unknown"
+  tst_compi_flistxattr="unknown"
+  tst_allow_flistxattr="unknown"
+  tst_nargs_flistxattr="unknown"
+  #
+  AC_MSG_CHECKING([if flistxattr can be linked])
+  AC_LINK_IFELSE([
+    AC_LANG_FUNC_LINK_TRY([flistxattr])
+  ],[
+    AC_MSG_RESULT([yes])
+    tst_links_flistxattr="yes"
+  ],[
+    AC_MSG_RESULT([no])
+    tst_links_flistxattr="no"
+  ])
+  #
+  if test "$tst_links_flistxattr" = "yes"; then
+    AC_MSG_CHECKING([if flistxattr is prototyped])
+    AC_EGREP_CPP([flistxattr],[
+      $curl_includes_sys_xattr
+    ],[
+      AC_MSG_RESULT([yes])
+      tst_proto_flistxattr="yes"
+    ],[
+      AC_MSG_RESULT([no])
+      tst_proto_flistxattr="no"
+    ])
+  fi
+  #
+  if test "$tst_proto_flistxattr" = "yes"; then
+    if test "$tst_nargs_flistxattr" = "unknown"; then
+      AC_MSG_CHECKING([if flistxattr takes 3 args.])
+      AC_COMPILE_IFELSE([
+        AC_LANG_PROGRAM([[
+          $curl_includes_sys_xattr
+        ]],[[
+          if(0 != flistxattr(0, 0, 0))
+            return 1;
+        ]])
+      ],[
+        AC_MSG_RESULT([yes])
+        tst_compi_flistxattr="yes"
+        tst_nargs_flistxattr="3"
+      ],[
+        AC_MSG_RESULT([no])
+        tst_compi_flistxattr="no"
+      ])
+    fi
+    if test "$tst_nargs_flistxattr" = "unknown"; then
+      AC_MSG_CHECKING([if flistxattr takes 4 args.])
+      AC_COMPILE_IFELSE([
+        AC_LANG_PROGRAM([[
+          $curl_includes_sys_xattr
+        ]],[[
+          if(0 != flistxattr(0, 0, 0, 0))
+            return 1;
+        ]])
+      ],[
+        AC_MSG_RESULT([yes])
+        tst_compi_flistxattr="yes"
+        tst_nargs_flistxattr="4"
+      ],[
+        AC_MSG_RESULT([no])
+        tst_compi_flistxattr="no"
+      ])
+    fi
+    AC_MSG_CHECKING([if flistxattr is compilable])
+    if test "$tst_compi_flistxattr" = "yes"; then
+      AC_MSG_RESULT([yes])
+    else
+      AC_MSG_RESULT([no])
+    fi
+  fi
+  #
+  if test "$tst_compi_flistxattr" = "yes"; then
+    AC_MSG_CHECKING([if flistxattr usage allowed])
+    if test "x$curl_disallow_flistxattr" != "xyes"; then
+      AC_MSG_RESULT([yes])
+      tst_allow_flistxattr="yes"
+    else
+      AC_MSG_RESULT([no])
+      tst_allow_flistxattr="no"
+    fi
+  fi
+  #
+  AC_MSG_CHECKING([if flistxattr might be used])
+  if test "$tst_links_flistxattr" = "yes" &&
+     test "$tst_proto_flistxattr" = "yes" &&
+     test "$tst_compi_flistxattr" = "yes" &&
+     test "$tst_allow_flistxattr" = "yes"; then
+    AC_MSG_RESULT([yes])
+    AC_DEFINE_UNQUOTED(HAVE_FLISTXATTR, 1,
+      [Define to 1 if you have the flistxattr function.])
+    dnl AC_DEFINE_UNQUOTED(FLISTXATTR_ARGS, $tst_nargs_flistxattr,
+    dnl   [Specifies the number of arguments to flistxattr])
+    #
+    if test "$tst_nargs_flistxattr" -eq "3"; then
+      AC_DEFINE(HAVE_FLISTXATTR_3, 1, [flistxattr() takes 3 args])
+    elif test "$tst_nargs_flistxattr" -eq "4"; then
+      AC_DEFINE(HAVE_FLISTXATTR_4, 1, [flistxattr() takes 4 args])
+    fi
+    #
+    curl_cv_func_flistxattr="yes"
+  else
+    AC_MSG_RESULT([no])
+    curl_cv_func_flistxattr="no"
+  fi
+])
+
+
+dnl CURL_CHECK_FUNC_FREEADDRINFO
+dnl -------------------------------------------------
+dnl Verify if freeaddrinfo is available, prototyped,
+dnl and can be compiled. If all of these are true,
+dnl and usage has not been previously disallowed with
+dnl shell variable curl_disallow_freeaddrinfo, then
+dnl HAVE_FREEADDRINFO will be defined.
+
+AC_DEFUN([CURL_CHECK_FUNC_FREEADDRINFO], [
+  AC_REQUIRE([CURL_INCLUDES_WS2TCPIP])dnl
+  AC_REQUIRE([CURL_INCLUDES_SYS_SOCKET])dnl
+  AC_REQUIRE([CURL_INCLUDES_NETDB])dnl
+  #
+  tst_links_freeaddrinfo="unknown"
+  tst_proto_freeaddrinfo="unknown"
+  tst_compi_freeaddrinfo="unknown"
+  tst_allow_freeaddrinfo="unknown"
+  #
+  AC_MSG_CHECKING([if freeaddrinfo can be linked])
+  AC_LINK_IFELSE([
+    AC_LANG_PROGRAM([[
+      $curl_includes_ws2tcpip
+      $curl_includes_sys_socket
+      $curl_includes_netdb
+    ]],[[
+      freeaddrinfo(0);
+    ]])
+  ],[
+    AC_MSG_RESULT([yes])
+    tst_links_freeaddrinfo="yes"
+  ],[
+    AC_MSG_RESULT([no])
+    tst_links_freeaddrinfo="no"
+  ])
+  #
+  if test "$tst_links_freeaddrinfo" = "yes"; then
+    AC_MSG_CHECKING([if freeaddrinfo is prototyped])
+    AC_EGREP_CPP([freeaddrinfo],[
+      $curl_includes_ws2tcpip
+      $curl_includes_sys_socket
+      $curl_includes_netdb
+    ],[
+      AC_MSG_RESULT([yes])
+      tst_proto_freeaddrinfo="yes"
+    ],[
+      AC_MSG_RESULT([no])
+      tst_proto_freeaddrinfo="no"
+    ])
+  fi
+  #
+  if test "$tst_proto_freeaddrinfo" = "yes"; then
+    AC_MSG_CHECKING([if freeaddrinfo is compilable])
+    AC_COMPILE_IFELSE([
+      AC_LANG_PROGRAM([[
+        $curl_includes_ws2tcpip
+        $curl_includes_sys_socket
+        $curl_includes_netdb
+      ]],[[
+        freeaddrinfo(0);
+      ]])
+    ],[
+      AC_MSG_RESULT([yes])
+      tst_compi_freeaddrinfo="yes"
+    ],[
+      AC_MSG_RESULT([no])
+      tst_compi_freeaddrinfo="no"
+    ])
+  fi
+  #
+  if test "$tst_compi_freeaddrinfo" = "yes"; then
+    AC_MSG_CHECKING([if freeaddrinfo usage allowed])
+    if test "x$curl_disallow_freeaddrinfo" != "xyes"; then
+      AC_MSG_RESULT([yes])
+      tst_allow_freeaddrinfo="yes"
+    else
+      AC_MSG_RESULT([no])
+      tst_allow_freeaddrinfo="no"
+    fi
+  fi
+  #
+  AC_MSG_CHECKING([if freeaddrinfo might be used])
+  if test "$tst_links_freeaddrinfo" = "yes" &&
+     test "$tst_proto_freeaddrinfo" = "yes" &&
+     test "$tst_compi_freeaddrinfo" = "yes" &&
+     test "$tst_allow_freeaddrinfo" = "yes"; then
+    AC_MSG_RESULT([yes])
+    AC_DEFINE_UNQUOTED(HAVE_FREEADDRINFO, 1,
+      [Define to 1 if you have the freeaddrinfo function.])
+    curl_cv_func_freeaddrinfo="yes"
+  else
+    AC_MSG_RESULT([no])
+    curl_cv_func_freeaddrinfo="no"
+  fi
+])
+
+
+dnl CURL_CHECK_FUNC_FREEIFADDRS
+dnl -------------------------------------------------
+dnl Verify if freeifaddrs is available, prototyped, and
+dnl can be compiled. If all of these are true, and
+dnl usage has not been previously disallowed with
+dnl shell variable curl_disallow_freeifaddrs, then
+dnl HAVE_FREEIFADDRS will be defined.
+
+AC_DEFUN([CURL_CHECK_FUNC_FREEIFADDRS], [
+  AC_REQUIRE([CURL_INCLUDES_IFADDRS])dnl
+  #
+  tst_links_freeifaddrs="unknown"
+  tst_proto_freeifaddrs="unknown"
+  tst_compi_freeifaddrs="unknown"
+  tst_allow_freeifaddrs="unknown"
+  #
+  AC_MSG_CHECKING([if freeifaddrs can be linked])
+  AC_LINK_IFELSE([
+    AC_LANG_FUNC_LINK_TRY([freeifaddrs])
+  ],[
+    AC_MSG_RESULT([yes])
+    tst_links_freeifaddrs="yes"
+  ],[
+    AC_MSG_RESULT([no])
+    tst_links_freeifaddrs="no"
+  ])
+  #
+  if test "$tst_links_freeifaddrs" = "yes"; then
+    AC_MSG_CHECKING([if freeifaddrs is prototyped])
+    AC_EGREP_CPP([freeifaddrs],[
+      $curl_includes_ifaddrs
+    ],[
+      AC_MSG_RESULT([yes])
+      tst_proto_freeifaddrs="yes"
+    ],[
+      AC_MSG_RESULT([no])
+      tst_proto_freeifaddrs="no"
+    ])
+  fi
+  #
+  if test "$tst_proto_freeifaddrs" = "yes"; then
+    AC_MSG_CHECKING([if freeifaddrs is compilable])
+    AC_COMPILE_IFELSE([
+      AC_LANG_PROGRAM([[
+        $curl_includes_ifaddrs
+      ]],[[
+        freeifaddrs(0);
+      ]])
+    ],[
+      AC_MSG_RESULT([yes])
+      tst_compi_freeifaddrs="yes"
+    ],[
+      AC_MSG_RESULT([no])
+      tst_compi_freeifaddrs="no"
+    ])
+  fi
+  #
+  if test "$tst_compi_freeifaddrs" = "yes"; then
+    AC_MSG_CHECKING([if freeifaddrs usage allowed])
+    if test "x$curl_disallow_freeifaddrs" != "xyes"; then
+      AC_MSG_RESULT([yes])
+      tst_allow_freeifaddrs="yes"
+    else
+      AC_MSG_RESULT([no])
+      tst_allow_freeifaddrs="no"
+    fi
+  fi
+  #
+  AC_MSG_CHECKING([if freeifaddrs might be used])
+  if test "$tst_links_freeifaddrs" = "yes" &&
+     test "$tst_proto_freeifaddrs" = "yes" &&
+     test "$tst_compi_freeifaddrs" = "yes" &&
+     test "$tst_allow_freeifaddrs" = "yes"; then
+    AC_MSG_RESULT([yes])
+    AC_DEFINE_UNQUOTED(HAVE_FREEIFADDRS, 1,
+      [Define to 1 if you have the freeifaddrs function.])
+    curl_cv_func_freeifaddrs="yes"
+  else
+    AC_MSG_RESULT([no])
+    curl_cv_func_freeifaddrs="no"
+  fi
+])
+
+
+dnl CURL_CHECK_FUNC_FREMOVEXATTR
+dnl -------------------------------------------------
+dnl Verify if fremovexattr is available, prototyped, and
+dnl can be compiled. If all of these are true, and
+dnl usage has not been previously disallowed with
+dnl shell variable curl_disallow_fremovexattr, then
+dnl HAVE_FREMOVEXATTR will be defined.
+
+AC_DEFUN([CURL_CHECK_FUNC_FREMOVEXATTR], [
+  AC_REQUIRE([CURL_INCLUDES_SYS_XATTR])dnl
+  #
+  tst_links_fremovexattr="unknown"
+  tst_proto_fremovexattr="unknown"
+  tst_compi_fremovexattr="unknown"
+  tst_allow_fremovexattr="unknown"
+  tst_nargs_fremovexattr="unknown"
+  #
+  AC_MSG_CHECKING([if fremovexattr can be linked])
+  AC_LINK_IFELSE([
+    AC_LANG_FUNC_LINK_TRY([fremovexattr])
+  ],[
+    AC_MSG_RESULT([yes])
+    tst_links_fremovexattr="yes"
+  ],[
+    AC_MSG_RESULT([no])
+    tst_links_fremovexattr="no"
+  ])
+  #
+  if test "$tst_links_fremovexattr" = "yes"; then
+    AC_MSG_CHECKING([if fremovexattr is prototyped])
+    AC_EGREP_CPP([fremovexattr],[
+      $curl_includes_sys_xattr
+    ],[
+      AC_MSG_RESULT([yes])
+      tst_proto_fremovexattr="yes"
+    ],[
+      AC_MSG_RESULT([no])
+      tst_proto_fremovexattr="no"
+    ])
+  fi
+  #
+  if test "$tst_proto_fremovexattr" = "yes"; then
+    if test "$tst_nargs_fremovexattr" = "unknown"; then
+      AC_MSG_CHECKING([if fremovexattr takes 2 args.])
+      AC_COMPILE_IFELSE([
+        AC_LANG_PROGRAM([[
+          $curl_includes_sys_xattr
+        ]],[[
+          if(0 != fremovexattr(0, 0))
+            return 1;
+        ]])
+      ],[
+        AC_MSG_RESULT([yes])
+        tst_compi_fremovexattr="yes"
+        tst_nargs_fremovexattr="2"
+      ],[
+        AC_MSG_RESULT([no])
+        tst_compi_fremovexattr="no"
+      ])
+    fi
+    if test "$tst_nargs_fremovexattr" = "unknown"; then
+      AC_MSG_CHECKING([if fremovexattr takes 3 args.])
+      AC_COMPILE_IFELSE([
+        AC_LANG_PROGRAM([[
+          $curl_includes_sys_xattr
+        ]],[[
+          if(0 != fremovexattr(0, 0, 0))
+            return 1;
+        ]])
+      ],[
+        AC_MSG_RESULT([yes])
+        tst_compi_fremovexattr="yes"
+        tst_nargs_fremovexattr="3"
+      ],[
+        AC_MSG_RESULT([no])
+        tst_compi_fremovexattr="no"
+      ])
+    fi
+    AC_MSG_CHECKING([if fremovexattr is compilable])
+    if test "$tst_compi_fremovexattr" = "yes"; then
+      AC_MSG_RESULT([yes])
+    else
+      AC_MSG_RESULT([no])
+    fi
+  fi
+  #
+  if test "$tst_compi_fremovexattr" = "yes"; then
+    AC_MSG_CHECKING([if fremovexattr usage allowed])
+    if test "x$curl_disallow_fremovexattr" != "xyes"; then
+      AC_MSG_RESULT([yes])
+      tst_allow_fremovexattr="yes"
+    else
+      AC_MSG_RESULT([no])
+      tst_allow_fremovexattr="no"
+    fi
+  fi
+  #
+  AC_MSG_CHECKING([if fremovexattr might be used])
+  if test "$tst_links_fremovexattr" = "yes" &&
+     test "$tst_proto_fremovexattr" = "yes" &&
+     test "$tst_compi_fremovexattr" = "yes" &&
+     test "$tst_allow_fremovexattr" = "yes"; then
+    AC_MSG_RESULT([yes])
+    AC_DEFINE_UNQUOTED(HAVE_FREMOVEXATTR, 1,
+      [Define to 1 if you have the fremovexattr function.])
+    dnl AC_DEFINE_UNQUOTED(FREMOVEXATTR_ARGS, $tst_nargs_fremovexattr,
+    dnl   [Specifies the number of arguments to fremovexattr])
+    #
+    if test "$tst_nargs_fremovexattr" -eq "2"; then
+      AC_DEFINE(HAVE_FREMOVEXATTR_2, 1, [fremovexattr() takes 2 args])
+    elif test "$tst_nargs_fremovexattr" -eq "3"; then
+      AC_DEFINE(HAVE_FREMOVEXATTR_3, 1, [fremovexattr() takes 3 args])
+    fi
+    #
+    curl_cv_func_fremovexattr="yes"
+  else
+    AC_MSG_RESULT([no])
+    curl_cv_func_fremovexattr="no"
+  fi
+])
+
+
+dnl CURL_CHECK_FUNC_FSETXATTR
+dnl -------------------------------------------------
+dnl Verify if fsetxattr is available, prototyped, and
+dnl can be compiled. If all of these are true, and
+dnl usage has not been previously disallowed with
+dnl shell variable curl_disallow_fsetxattr, then
+dnl HAVE_FSETXATTR will be defined.
+
+AC_DEFUN([CURL_CHECK_FUNC_FSETXATTR], [
+  AC_REQUIRE([CURL_INCLUDES_SYS_XATTR])dnl
+  #
+  tst_links_fsetxattr="unknown"
+  tst_proto_fsetxattr="unknown"
+  tst_compi_fsetxattr="unknown"
+  tst_allow_fsetxattr="unknown"
+  tst_nargs_fsetxattr="unknown"
+  #
+  AC_MSG_CHECKING([if fsetxattr can be linked])
+  AC_LINK_IFELSE([
+    AC_LANG_FUNC_LINK_TRY([fsetxattr])
+  ],[
+    AC_MSG_RESULT([yes])
+    tst_links_fsetxattr="yes"
+  ],[
+    AC_MSG_RESULT([no])
+    tst_links_fsetxattr="no"
+  ])
+  #
+  if test "$tst_links_fsetxattr" = "yes"; then
+    AC_MSG_CHECKING([if fsetxattr is prototyped])
+    AC_EGREP_CPP([fsetxattr],[
+      $curl_includes_sys_xattr
+    ],[
+      AC_MSG_RESULT([yes])
+      tst_proto_fsetxattr="yes"
+    ],[
+      AC_MSG_RESULT([no])
+      tst_proto_fsetxattr="no"
+    ])
+  fi
+  #
+  if test "$tst_proto_fsetxattr" = "yes"; then
+    if test "$tst_nargs_fsetxattr" = "unknown"; then
+      AC_MSG_CHECKING([if fsetxattr takes 5 args.])
+      AC_COMPILE_IFELSE([
+        AC_LANG_PROGRAM([[
+          $curl_includes_sys_xattr
+        ]],[[
+          if(0 != fsetxattr(0, 0, 0, 0, 0))
+            return 1;
+        ]])
+      ],[
+        AC_MSG_RESULT([yes])
+        tst_compi_fsetxattr="yes"
+        tst_nargs_fsetxattr="5"
+      ],[
+        AC_MSG_RESULT([no])
+        tst_compi_fsetxattr="no"
+      ])
+    fi
+    if test "$tst_nargs_fsetxattr" = "unknown"; then
+      AC_MSG_CHECKING([if fsetxattr takes 6 args.])
+      AC_COMPILE_IFELSE([
+        AC_LANG_PROGRAM([[
+          $curl_includes_sys_xattr
+        ]],[[
+          if(0 != fsetxattr(0, 0, 0, 0, 0, 0))
+            return 1;
+        ]])
+      ],[
+        AC_MSG_RESULT([yes])
+        tst_compi_fsetxattr="yes"
+        tst_nargs_fsetxattr="6"
+      ],[
+        AC_MSG_RESULT([no])
+        tst_compi_fsetxattr="no"
+      ])
+    fi
+    AC_MSG_CHECKING([if fsetxattr is compilable])
+    if test "$tst_compi_fsetxattr" = "yes"; then
+      AC_MSG_RESULT([yes])
+    else
+      AC_MSG_RESULT([no])
+    fi
+  fi
+  #
+  if test "$tst_compi_fsetxattr" = "yes"; then
+    AC_MSG_CHECKING([if fsetxattr usage allowed])
+    if test "x$curl_disallow_fsetxattr" != "xyes"; then
+      AC_MSG_RESULT([yes])
+      tst_allow_fsetxattr="yes"
+    else
+      AC_MSG_RESULT([no])
+      tst_allow_fsetxattr="no"
+    fi
+  fi
+  #
+  AC_MSG_CHECKING([if fsetxattr might be used])
+  if test "$tst_links_fsetxattr" = "yes" &&
+     test "$tst_proto_fsetxattr" = "yes" &&
+     test "$tst_compi_fsetxattr" = "yes" &&
+     test "$tst_allow_fsetxattr" = "yes"; then
+    AC_MSG_RESULT([yes])
+    AC_DEFINE_UNQUOTED(HAVE_FSETXATTR, 1,
+      [Define to 1 if you have the fsetxattr function.])
+    dnl AC_DEFINE_UNQUOTED(FSETXATTR_ARGS, $tst_nargs_fsetxattr,
+    dnl   [Specifies the number of arguments to fsetxattr])
+    #
+    if test "$tst_nargs_fsetxattr" -eq "5"; then
+      AC_DEFINE(HAVE_FSETXATTR_5, 1, [fsetxattr() takes 5 args])
+    elif test "$tst_nargs_fsetxattr" -eq "6"; then
+      AC_DEFINE(HAVE_FSETXATTR_6, 1, [fsetxattr() takes 6 args])
+    fi
+    #
+    curl_cv_func_fsetxattr="yes"
+  else
+    AC_MSG_RESULT([no])
+    curl_cv_func_fsetxattr="no"
+  fi
+])
+
+
+dnl CURL_CHECK_FUNC_FTRUNCATE
+dnl -------------------------------------------------
+dnl Verify if ftruncate is available, prototyped, and
+dnl can be compiled. If all of these are true, and
+dnl usage has not been previously disallowed with
+dnl shell variable curl_disallow_ftruncate, then
+dnl HAVE_FTRUNCATE will be defined.
+
+AC_DEFUN([CURL_CHECK_FUNC_FTRUNCATE], [
+  AC_REQUIRE([CURL_INCLUDES_UNISTD])dnl
+  #
+  tst_links_ftruncate="unknown"
+  tst_proto_ftruncate="unknown"
+  tst_compi_ftruncate="unknown"
+  tst_allow_ftruncate="unknown"
+  #
+  AC_MSG_CHECKING([if ftruncate can be linked])
+  AC_LINK_IFELSE([
+    AC_LANG_FUNC_LINK_TRY([ftruncate])
+  ],[
+    AC_MSG_RESULT([yes])
+    tst_links_ftruncate="yes"
+  ],[
+    AC_MSG_RESULT([no])
+    tst_links_ftruncate="no"
+  ])
+  #
+  if test "$tst_links_ftruncate" = "yes"; then
+    AC_MSG_CHECKING([if ftruncate is prototyped])
+    AC_EGREP_CPP([ftruncate],[
+      $curl_includes_unistd
+    ],[
+      AC_MSG_RESULT([yes])
+      tst_proto_ftruncate="yes"
+    ],[
+      AC_MSG_RESULT([no])
+      tst_proto_ftruncate="no"
+    ])
+  fi
+  #
+  if test "$tst_proto_ftruncate" = "yes"; then
+    AC_MSG_CHECKING([if ftruncate is compilable])
+    AC_COMPILE_IFELSE([
+      AC_LANG_PROGRAM([[
+        $curl_includes_unistd
+      ]],[[
+        if(0 != ftruncate(0, 0))
+          return 1;
+      ]])
+    ],[
+      AC_MSG_RESULT([yes])
+      tst_compi_ftruncate="yes"
+    ],[
+      AC_MSG_RESULT([no])
+      tst_compi_ftruncate="no"
+    ])
+  fi
+  #
+  if test "$tst_compi_ftruncate" = "yes"; then
+    AC_MSG_CHECKING([if ftruncate usage allowed])
+    if test "x$curl_disallow_ftruncate" != "xyes"; then
+      AC_MSG_RESULT([yes])
+      tst_allow_ftruncate="yes"
+    else
+      AC_MSG_RESULT([no])
+      tst_allow_ftruncate="no"
+    fi
+  fi
+  #
+  AC_MSG_CHECKING([if ftruncate might be used])
+  if test "$tst_links_ftruncate" = "yes" &&
+     test "$tst_proto_ftruncate" = "yes" &&
+     test "$tst_compi_ftruncate" = "yes" &&
+     test "$tst_allow_ftruncate" = "yes"; then
+    AC_MSG_RESULT([yes])
+    AC_DEFINE_UNQUOTED(HAVE_FTRUNCATE, 1,
+      [Define to 1 if you have the ftruncate function.])
+    curl_cv_func_ftruncate="yes"
+  else
+    AC_MSG_RESULT([no])
+    curl_cv_func_ftruncate="no"
+  fi
+])
+
+
+dnl CURL_CHECK_FUNC_GETADDRINFO
+dnl -------------------------------------------------
+dnl Verify if getaddrinfo is available, prototyped, can
+dnl be compiled and seems to work. If all of these are
+dnl true, and usage has not been previously disallowed
+dnl with shell variable curl_disallow_getaddrinfo, then
+dnl HAVE_GETADDRINFO will be defined. Additionally when
+dnl HAVE_GETADDRINFO gets defined this will also attempt
+dnl to find out if getaddrinfo happens to be threadsafe,
+dnl defining HAVE_GETADDRINFO_THREADSAFE when true.
+
+AC_DEFUN([CURL_CHECK_FUNC_GETADDRINFO], [
+  AC_REQUIRE([CURL_INCLUDES_WS2TCPIP])dnl
+  AC_REQUIRE([CURL_INCLUDES_STDLIB])dnl
+  AC_REQUIRE([CURL_INCLUDES_STRING])dnl
+  AC_REQUIRE([CURL_INCLUDES_SYS_SOCKET])dnl
+  AC_REQUIRE([CURL_INCLUDES_NETDB])dnl
+  AC_REQUIRE([CURL_CHECK_NATIVE_WINDOWS])dnl
+  #
+  tst_links_getaddrinfo="unknown"
+  tst_proto_getaddrinfo="unknown"
+  tst_compi_getaddrinfo="unknown"
+  tst_works_getaddrinfo="unknown"
+  tst_allow_getaddrinfo="unknown"
+  tst_tsafe_getaddrinfo="unknown"
+  #
+  AC_MSG_CHECKING([if getaddrinfo can be linked])
+  AC_LINK_IFELSE([
+    AC_LANG_PROGRAM([[
+      $curl_includes_ws2tcpip
+      $curl_includes_sys_socket
+      $curl_includes_netdb
+    ]],[[
+      if(0 != getaddrinfo(0, 0, 0, 0))
+        return 1;
+    ]])
+  ],[
+    AC_MSG_RESULT([yes])
+    tst_links_getaddrinfo="yes"
+  ],[
+    AC_MSG_RESULT([no])
+    tst_links_getaddrinfo="no"
+  ])
+  #
+  if test "$tst_links_getaddrinfo" = "yes"; then
+    AC_MSG_CHECKING([if getaddrinfo is prototyped])
+    AC_EGREP_CPP([getaddrinfo],[
+      $curl_includes_ws2tcpip
+      $curl_includes_sys_socket
+      $curl_includes_netdb
+    ],[
+      AC_MSG_RESULT([yes])
+      tst_proto_getaddrinfo="yes"
+    ],[
+      AC_MSG_RESULT([no])
+      tst_proto_getaddrinfo="no"
+    ])
+  fi
+  #
+  if test "$tst_proto_getaddrinfo" = "yes"; then
+    AC_MSG_CHECKING([if getaddrinfo is compilable])
+    AC_COMPILE_IFELSE([
+      AC_LANG_PROGRAM([[
+        $curl_includes_ws2tcpip
+        $curl_includes_sys_socket
+        $curl_includes_netdb
+      ]],[[
+        if(0 != getaddrinfo(0, 0, 0, 0))
+          return 1;
+      ]])
+    ],[
+      AC_MSG_RESULT([yes])
+      tst_compi_getaddrinfo="yes"
+    ],[
+      AC_MSG_RESULT([no])
+      tst_compi_getaddrinfo="no"
+    ])
+  fi
+  #
+  dnl only do runtime verification when not cross-compiling
+  if test "x$cross_compiling" != "xyes" &&
+    test "$tst_compi_getaddrinfo" = "yes"; then
+    AC_MSG_CHECKING([if getaddrinfo seems to work])
+    AC_RUN_IFELSE([
+      AC_LANG_PROGRAM([[
+        $curl_includes_ws2tcpip
+        $curl_includes_stdlib
+        $curl_includes_string
+        $curl_includes_sys_socket
+        $curl_includes_netdb
+      ]],[[
+        struct addrinfo hints;
+        struct addrinfo *ai = 0;
+        int error;
+
+        #ifdef HAVE_WINSOCK2_H
+        WSADATA wsa;
+        if (WSAStartup(MAKEWORD(2,2), &wsa))
+                exit(2);
+        #endif
+
+        memset(&hints, 0, sizeof(hints));
+        hints.ai_flags = AI_NUMERICHOST;
+        hints.ai_family = AF_UNSPEC;
+        hints.ai_socktype = SOCK_STREAM;
+        error = getaddrinfo("127.0.0.1", 0, &hints, &ai);
+        if(error || !ai)
+          exit(1); /* fail */
+        else
+          exit(0);
+      ]])
+    ],[
+      AC_MSG_RESULT([yes])
+      tst_works_getaddrinfo="yes"
+    ],[
+      AC_MSG_RESULT([no])
+      tst_works_getaddrinfo="no"
+    ])
+  fi
+  #
+  if test "$tst_compi_getaddrinfo" = "yes" &&
+    test "$tst_works_getaddrinfo" != "no"; then
+    AC_MSG_CHECKING([if getaddrinfo usage allowed])
+    if test "x$curl_disallow_getaddrinfo" != "xyes"; then
+      AC_MSG_RESULT([yes])
+      tst_allow_getaddrinfo="yes"
+    else
+      AC_MSG_RESULT([no])
+      tst_allow_getaddrinfo="no"
+    fi
+  fi
+  #
+  AC_MSG_CHECKING([if getaddrinfo might be used])
+  if test "$tst_links_getaddrinfo" = "yes" &&
+     test "$tst_proto_getaddrinfo" = "yes" &&
+     test "$tst_compi_getaddrinfo" = "yes" &&
+     test "$tst_allow_getaddrinfo" = "yes" &&
+     test "$tst_works_getaddrinfo" != "no"; then
+    AC_MSG_RESULT([yes])
+    AC_DEFINE_UNQUOTED(HAVE_GETADDRINFO, 1,
+      [Define to 1 if you have a working getaddrinfo function.])
+    curl_cv_func_getaddrinfo="yes"
+  else
+    AC_MSG_RESULT([no])
+    curl_cv_func_getaddrinfo="no"
+    curl_cv_func_getaddrinfo_threadsafe="no"
+  fi
+  #
+  if test "$curl_cv_func_getaddrinfo" = "yes"; then
+    AC_MSG_CHECKING([if getaddrinfo is threadsafe])
+    case $host_os in
+      aix[[1234]].* | aix5.[[01]].*)
+        dnl aix 5.1 and older
+        tst_tsafe_getaddrinfo="no"
+        ;;
+      aix*)
+        dnl aix 5.2 and newer
+        tst_tsafe_getaddrinfo="yes"
+        ;;
+      darwin[[12345]].*)
+        dnl darwin 5.0 and mac os x 10.1.X and older
+        tst_tsafe_getaddrinfo="no"
+        ;;
+      darwin*)
+        dnl darwin 6.0 and mac os x 10.2.X and newer
+        tst_tsafe_getaddrinfo="yes"
+        ;;
+      freebsd[[1234]].* | freebsd5.[[1234]]*)
+        dnl freebsd 5.4 and older
+        tst_tsafe_getaddrinfo="no"
+        ;;
+      freebsd*)
+        dnl freebsd 5.5 and newer
+        tst_tsafe_getaddrinfo="yes"
+        ;;
+      hpux[[123456789]].* | hpux10.* | hpux11.0* | hpux11.10*)
+        dnl hpux 11.10 and older
+        tst_tsafe_getaddrinfo="no"
+        ;;
+      hpux*)
+        dnl hpux 11.11 and newer
+        tst_tsafe_getaddrinfo="yes"
+        ;;
+      netbsd[[123]].*)
+        dnl netbsd 3.X and older
+        tst_tsafe_getaddrinfo="no"
+        ;;
+      netbsd*)
+        dnl netbsd 4.X and newer
+        tst_tsafe_getaddrinfo="yes"
+        ;;
+      *bsd*)
+        dnl All other bsd's
+        tst_tsafe_getaddrinfo="no"
+        ;;
+      solaris2*)
+        dnl solaris which have it
+        tst_tsafe_getaddrinfo="yes"
+        ;;
+    esac
+    if test "$tst_tsafe_getaddrinfo" = "unknown" &&
+       test "$curl_cv_native_windows" = "yes"; then
+      tst_tsafe_getaddrinfo="yes"
+    fi
+    if test "$tst_tsafe_getaddrinfo" = "unknown"; then
+      CURL_CHECK_DEF_CC([h_errno], [
+        $curl_includes_sys_socket
+        $curl_includes_netdb
+        ], [silent])
+      if test "$curl_cv_have_def_h_errno" = "yes"; then
+        tst_h_errno_macro="yes"
+      else
+        tst_h_errno_macro="no"
+      fi
+      AC_COMPILE_IFELSE([
+        AC_LANG_PROGRAM([[
+          $curl_includes_sys_socket
+          $curl_includes_netdb
+        ]],[[
+          h_errno = 2;
+          if(0 != h_errno)
+            return 1;
+        ]])
+      ],[
+        tst_h_errno_modifiable_lvalue="yes"
+      ],[
+        tst_h_errno_modifiable_lvalue="no"
+      ])
+      AC_COMPILE_IFELSE([
+        AC_LANG_PROGRAM([[
+        ]],[[
+#if defined(_POSIX_C_SOURCE) && (_POSIX_C_SOURCE >= 200809L)
+          return 0;
+#elif defined(_XOPEN_SOURCE) && (_XOPEN_SOURCE >= 700)
+          return 0;
+#else
+          force compilation error
+#endif
+        ]])
+      ],[
+        tst_h_errno_sbs_issue_7="yes"
+      ],[
+        tst_h_errno_sbs_issue_7="no"
+      ])
+      if test "$tst_h_errno_macro" = "no" &&
+         test "$tst_h_errno_modifiable_lvalue" = "no" &&
+         test "$tst_h_errno_sbs_issue_7" = "no"; then
+        tst_tsafe_getaddrinfo="no"
+      else
+        tst_tsafe_getaddrinfo="yes"
+      fi
+    fi
+    AC_MSG_RESULT([$tst_tsafe_getaddrinfo])
+    if test "$tst_tsafe_getaddrinfo" = "yes"; then
+      AC_DEFINE_UNQUOTED(HAVE_GETADDRINFO_THREADSAFE, 1,
+        [Define to 1 if the getaddrinfo function is threadsafe.])
+      curl_cv_func_getaddrinfo_threadsafe="yes"
+    else
+      curl_cv_func_getaddrinfo_threadsafe="no"
+    fi
+  fi
+])
+
+
+dnl CURL_CHECK_FUNC_GETHOSTBYADDR
+dnl -------------------------------------------------
+dnl Verify if gethostbyaddr is available, prototyped,
+dnl and can be compiled. If all of these are true,
+dnl and usage has not been previously disallowed with
+dnl shell variable curl_disallow_gethostbyaddr, then
+dnl HAVE_GETHOSTBYADDR will be defined.
+
+AC_DEFUN([CURL_CHECK_FUNC_GETHOSTBYADDR], [
+  AC_REQUIRE([CURL_INCLUDES_WINSOCK2])dnl
+  AC_REQUIRE([CURL_INCLUDES_NETDB])dnl
+  #
+  tst_links_gethostbyaddr="unknown"
+  tst_proto_gethostbyaddr="unknown"
+  tst_compi_gethostbyaddr="unknown"
+  tst_allow_gethostbyaddr="unknown"
+  #
+  AC_MSG_CHECKING([if gethostbyaddr can be linked])
+  AC_LINK_IFELSE([
+    AC_LANG_PROGRAM([[
+      $curl_includes_winsock2
+      $curl_includes_netdb
+    ]],[[
+      if(0 != gethostbyaddr(0, 0, 0))
+        return 1;
+    ]])
+  ],[
+    AC_MSG_RESULT([yes])
+    tst_links_gethostbyaddr="yes"
+  ],[
+    AC_MSG_RESULT([no])
+    tst_links_gethostbyaddr="no"
+  ])
+  #
+  if test "$tst_links_gethostbyaddr" = "yes"; then
+    AC_MSG_CHECKING([if gethostbyaddr is prototyped])
+    AC_EGREP_CPP([gethostbyaddr],[
+      $curl_includes_winsock2
+      $curl_includes_netdb
+    ],[
+      AC_MSG_RESULT([yes])
+      tst_proto_gethostbyaddr="yes"
+    ],[
+      AC_MSG_RESULT([no])
+      tst_proto_gethostbyaddr="no"
+    ])
+  fi
+  #
+  if test "$tst_proto_gethostbyaddr" = "yes"; then
+    AC_MSG_CHECKING([if gethostbyaddr is compilable])
+    AC_COMPILE_IFELSE([
+      AC_LANG_PROGRAM([[
+        $curl_includes_winsock2
+        $curl_includes_netdb
+      ]],[[
+        if(0 != gethostbyaddr(0, 0, 0))
+          return 1;
+      ]])
+    ],[
+      AC_MSG_RESULT([yes])
+      tst_compi_gethostbyaddr="yes"
+    ],[
+      AC_MSG_RESULT([no])
+      tst_compi_gethostbyaddr="no"
+    ])
+  fi
+  #
+  if test "$tst_compi_gethostbyaddr" = "yes"; then
+    AC_MSG_CHECKING([if gethostbyaddr usage allowed])
+    if test "x$curl_disallow_gethostbyaddr" != "xyes"; then
+      AC_MSG_RESULT([yes])
+      tst_allow_gethostbyaddr="yes"
+    else
+      AC_MSG_RESULT([no])
+      tst_allow_gethostbyaddr="no"
+    fi
+  fi
+  #
+  AC_MSG_CHECKING([if gethostbyaddr might be used])
+  if test "$tst_links_gethostbyaddr" = "yes" &&
+     test "$tst_proto_gethostbyaddr" = "yes" &&
+     test "$tst_compi_gethostbyaddr" = "yes" &&
+     test "$tst_allow_gethostbyaddr" = "yes"; then
+    AC_MSG_RESULT([yes])
+    AC_DEFINE_UNQUOTED(HAVE_GETHOSTBYADDR, 1,
+      [Define to 1 if you have the gethostbyaddr function.])
+    curl_cv_func_gethostbyaddr="yes"
+  else
+    AC_MSG_RESULT([no])
+    curl_cv_func_gethostbyaddr="no"
+  fi
+])
+
+dnl CURL_CHECK_FUNC_GAI_STRERROR
+dnl -------------------------------------------------
+dnl Verify if gai_strerror is available, prototyped,
+dnl and can be compiled. If all of these are true,
+dnl and usage has not been previously disallowed with
+dnl shell variable curl_disallow_gai_strerror, then
+dnl HAVE_GAI_STRERROR will be defined.
+
+AC_DEFUN([CURL_CHECK_FUNC_GAI_STRERROR], [
+  AC_REQUIRE([CURL_INCLUDES_WINSOCK2])dnl
+  AC_REQUIRE([CURL_INCLUDES_NETDB])dnl
+  #
+  tst_links_gai_strerror="unknown"
+  tst_proto_gai_strerror="unknown"
+  tst_compi_gai_strerror="unknown"
+  tst_allow_gai_strerror="unknown"
+  #
+  AC_MSG_CHECKING([if gai_strerror can be linked])
+  AC_LINK_IFELSE([
+    AC_LANG_PROGRAM([[
+      $curl_includes_winsock2
+      $curl_includes_netdb
+    ]],[[
+      if(0 != gai_strerror(0))
+        return 1;
+    ]])
+  ],[
+    AC_MSG_RESULT([yes])
+    tst_links_gai_strerror="yes"
+  ],[
+    AC_MSG_RESULT([no])
+    tst_links_gai_strerror="no"
+  ])
+  #
+  if test "$tst_links_gai_strerror" = "yes"; then
+    AC_MSG_CHECKING([if gai_strerror is prototyped])
+    AC_EGREP_CPP([gai_strerror],[
+      $curl_includes_winsock2
+      $curl_includes_netdb
+    ],[
+      AC_MSG_RESULT([yes])
+      tst_proto_gai_strerror="yes"
+    ],[
+      AC_MSG_RESULT([no])
+      tst_proto_gai_strerror="no"
+    ])
+  fi
+  #
+  if test "$tst_proto_gai_strerror" = "yes"; then
+    AC_MSG_CHECKING([if gai_strerror is compilable])
+    AC_COMPILE_IFELSE([
+      AC_LANG_PROGRAM([[
+        $curl_includes_winsock2
+        $curl_includes_netdb
+      ]],[[
+        if(0 != gai_strerror(0))
+          return 1;
+      ]])
+    ],[
+      AC_MSG_RESULT([yes])
+      tst_compi_gai_strerror="yes"
+    ],[
+      AC_MSG_RESULT([no])
+      tst_compi_gai_strerror="no"
+    ])
+  fi
+  #
+  if test "$tst_compi_gai_strerror" = "yes"; then
+    AC_MSG_CHECKING([if gai_strerror usage allowed])
+    if test "x$curl_disallow_gai_strerror" != "xyes"; then
+      AC_MSG_RESULT([yes])
+      tst_allow_gai_strerror="yes"
+    else
+      AC_MSG_RESULT([no])
+      tst_allow_gai_strerror="no"
+    fi
+  fi
+  #
+  AC_MSG_CHECKING([if gai_strerror might be used])
+  if test "$tst_links_gai_strerror" = "yes" &&
+     test "$tst_proto_gai_strerror" = "yes" &&
+     test "$tst_compi_gai_strerror" = "yes" &&
+     test "$tst_allow_gai_strerror" = "yes"; then
+    AC_MSG_RESULT([yes])
+    AC_DEFINE_UNQUOTED(HAVE_GAI_STRERROR, 1,
+      [Define to 1 if you have the gai_strerror function.])
+    curl_cv_func_gai_strerror="yes"
+  else
+    AC_MSG_RESULT([no])
+    curl_cv_func_gai_strerror="no"
+  fi
+])
+
+
+dnl CURL_CHECK_FUNC_GETHOSTBYADDR_R
+dnl -------------------------------------------------
+dnl Verify if gethostbyaddr_r is available, prototyped,
+dnl and can be compiled. If all of these are true, and
+dnl usage has not been previously disallowed with
+dnl shell variable curl_disallow_gethostbyaddr_r, then
+dnl HAVE_GETHOSTBYADDR_R will be defined.
+
+AC_DEFUN([CURL_CHECK_FUNC_GETHOSTBYADDR_R], [
+  AC_REQUIRE([CURL_INCLUDES_NETDB])dnl
+  #
+  tst_links_gethostbyaddr_r="unknown"
+  tst_proto_gethostbyaddr_r="unknown"
+  tst_compi_gethostbyaddr_r="unknown"
+  tst_allow_gethostbyaddr_r="unknown"
+  tst_nargs_gethostbyaddr_r="unknown"
+  #
+  AC_MSG_CHECKING([if gethostbyaddr_r can be linked])
+  AC_LINK_IFELSE([
+    AC_LANG_FUNC_LINK_TRY([gethostbyaddr_r])
+  ],[
+    AC_MSG_RESULT([yes])
+    tst_links_gethostbyaddr_r="yes"
+  ],[
+    AC_MSG_RESULT([no])
+    tst_links_gethostbyaddr_r="no"
+  ])
+  #
+  if test "$tst_links_gethostbyaddr_r" = "yes"; then
+    AC_MSG_CHECKING([if gethostbyaddr_r is prototyped])
+    AC_EGREP_CPP([gethostbyaddr_r],[
+      $curl_includes_netdb
+    ],[
+      AC_MSG_RESULT([yes])
+      tst_proto_gethostbyaddr_r="yes"
+    ],[
+      AC_MSG_RESULT([no])
+      tst_proto_gethostbyaddr_r="no"
+    ])
+  fi
+  #
+  if test "$tst_proto_gethostbyaddr_r" = "yes"; then
+    if test "$tst_nargs_gethostbyaddr_r" = "unknown"; then
+      AC_MSG_CHECKING([if gethostbyaddr_r takes 5 args.])
+      AC_COMPILE_IFELSE([
+        AC_LANG_PROGRAM([[
+          $curl_includes_netdb
+        ]],[[
+          if(0 != gethostbyaddr_r(0, 0, 0, 0, 0))
+            return 1;
+        ]])
+      ],[
+        AC_MSG_RESULT([yes])
+        tst_compi_gethostbyaddr_r="yes"
+        tst_nargs_gethostbyaddr_r="5"
+      ],[
+        AC_MSG_RESULT([no])
+        tst_compi_gethostbyaddr_r="no"
+      ])
+    fi
+    if test "$tst_nargs_gethostbyaddr_r" = "unknown"; then
+      AC_MSG_CHECKING([if gethostbyaddr_r takes 7 args.])
+      AC_COMPILE_IFELSE([
+        AC_LANG_PROGRAM([[
+          $curl_includes_netdb
+        ]],[[
+          if(0 != gethostbyaddr_r(0, 0, 0, 0, 0, 0, 0))
+            return 1;
+        ]])
+      ],[
+        AC_MSG_RESULT([yes])
+        tst_compi_gethostbyaddr_r="yes"
+        tst_nargs_gethostbyaddr_r="7"
+      ],[
+        AC_MSG_RESULT([no])
+        tst_compi_gethostbyaddr_r="no"
+      ])
+    fi
+    if test "$tst_nargs_gethostbyaddr_r" = "unknown"; then
+      AC_MSG_CHECKING([if gethostbyaddr_r takes 8 args.])
+      AC_COMPILE_IFELSE([
+        AC_LANG_PROGRAM([[
+          $curl_includes_netdb
+        ]],[[
+          if(0 != gethostbyaddr_r(0, 0, 0, 0, 0, 0, 0, 0))
+            return 1;
+        ]])
+      ],[
+        AC_MSG_RESULT([yes])
+        tst_compi_gethostbyaddr_r="yes"
+        tst_nargs_gethostbyaddr_r="8"
+      ],[
+        AC_MSG_RESULT([no])
+        tst_compi_gethostbyaddr_r="no"
+      ])
+    fi
+    AC_MSG_CHECKING([if gethostbyaddr_r is compilable])
+    if test "$tst_compi_gethostbyaddr_r" = "yes"; then
+      AC_MSG_RESULT([yes])
+    else
+      AC_MSG_RESULT([no])
+    fi
+  fi
+  #
+  if test "$tst_compi_gethostbyaddr_r" = "yes"; then
+    AC_MSG_CHECKING([if gethostbyaddr_r usage allowed])
+    if test "x$curl_disallow_gethostbyaddr_r" != "xyes"; then
+      AC_MSG_RESULT([yes])
+      tst_allow_gethostbyaddr_r="yes"
+    else
+      AC_MSG_RESULT([no])
+      tst_allow_gethostbyaddr_r="no"
+    fi
+  fi
+  #
+  AC_MSG_CHECKING([if gethostbyaddr_r might be used])
+  if test "$tst_links_gethostbyaddr_r" = "yes" &&
+     test "$tst_proto_gethostbyaddr_r" = "yes" &&
+     test "$tst_compi_gethostbyaddr_r" = "yes" &&
+     test "$tst_allow_gethostbyaddr_r" = "yes"; then
+    AC_MSG_RESULT([yes])
+    AC_DEFINE_UNQUOTED(HAVE_GETHOSTBYADDR_R, 1,
+      [Define to 1 if you have the gethostbyaddr_r function.])
+    dnl AC_DEFINE_UNQUOTED(GETHOSTBYADDR_R_ARGS, $tst_nargs_gethostbyaddr_r,
+    dnl   [Specifies the number of arguments to gethostbyaddr_r])
+    #
+    if test "$tst_nargs_gethostbyaddr_r" -eq "5"; then
+      AC_DEFINE(HAVE_GETHOSTBYADDR_R_5, 1, [gethostbyaddr_r() takes 5 args])
+    elif test "$tst_nargs_gethostbyaddr_r" -eq "7"; then
+      AC_DEFINE(HAVE_GETHOSTBYADDR_R_7, 1, [gethostbyaddr_r() takes 7 args])
+    elif test "$tst_nargs_gethostbyaddr_r" -eq "8"; then
+      AC_DEFINE(HAVE_GETHOSTBYADDR_R_8, 1, [gethostbyaddr_r() takes 8 args])
+    fi
+    #
+    curl_cv_func_gethostbyaddr_r="yes"
+  else
+    AC_MSG_RESULT([no])
+    curl_cv_func_gethostbyaddr_r="no"
+  fi
+])
+
+
+dnl CURL_CHECK_FUNC_GETHOSTBYNAME
+dnl -------------------------------------------------
+dnl Verify if gethostbyname is available, prototyped,
+dnl and can be compiled. If all of these are true,
+dnl and usage has not been previously disallowed with
+dnl shell variable curl_disallow_gethostbyname, then
+dnl HAVE_GETHOSTBYNAME will be defined.
+
+AC_DEFUN([CURL_CHECK_FUNC_GETHOSTBYNAME], [
+  AC_REQUIRE([CURL_INCLUDES_WINSOCK2])dnl
+  AC_REQUIRE([CURL_INCLUDES_NETDB])dnl
+  #
+  tst_links_gethostbyname="unknown"
+  tst_proto_gethostbyname="unknown"
+  tst_compi_gethostbyname="unknown"
+  tst_allow_gethostbyname="unknown"
+  #
+  AC_MSG_CHECKING([if gethostbyname can be linked])
+  AC_LINK_IFELSE([
+    AC_LANG_PROGRAM([[
+      $curl_includes_winsock2
+      $curl_includes_netdb
+    ]],[[
+      if(0 != gethostbyname(0))
+        return 1;
+    ]])
+  ],[
+    AC_MSG_RESULT([yes])
+    tst_links_gethostbyname="yes"
+  ],[
+    AC_MSG_RESULT([no])
+    tst_links_gethostbyname="no"
+  ])
+  #
+  if test "$tst_links_gethostbyname" = "yes"; then
+    AC_MSG_CHECKING([if gethostbyname is prototyped])
+    AC_EGREP_CPP([gethostbyname],[
+      $curl_includes_winsock2
+      $curl_includes_netdb
+    ],[
+      AC_MSG_RESULT([yes])
+      tst_proto_gethostbyname="yes"
+    ],[
+      AC_MSG_RESULT([no])
+      tst_proto_gethostbyname="no"
+    ])
+  fi
+  #
+  if test "$tst_proto_gethostbyname" = "yes"; then
+    AC_MSG_CHECKING([if gethostbyname is compilable])
+    AC_COMPILE_IFELSE([
+      AC_LANG_PROGRAM([[
+        $curl_includes_winsock2
+        $curl_includes_netdb
+      ]],[[
+        if(0 != gethostbyname(0))
+          return 1;
+      ]])
+    ],[
+      AC_MSG_RESULT([yes])
+      tst_compi_gethostbyname="yes"
+    ],[
+      AC_MSG_RESULT([no])
+      tst_compi_gethostbyname="no"
+    ])
+  fi
+  #
+  if test "$tst_compi_gethostbyname" = "yes"; then
+    AC_MSG_CHECKING([if gethostbyname usage allowed])
+    if test "x$curl_disallow_gethostbyname" != "xyes"; then
+      AC_MSG_RESULT([yes])
+      tst_allow_gethostbyname="yes"
+    else
+      AC_MSG_RESULT([no])
+      tst_allow_gethostbyname="no"
+    fi
+  fi
+  #
+  AC_MSG_CHECKING([if gethostbyname might be used])
+  if test "$tst_links_gethostbyname" = "yes" &&
+     test "$tst_proto_gethostbyname" = "yes" &&
+     test "$tst_compi_gethostbyname" = "yes" &&
+     test "$tst_allow_gethostbyname" = "yes"; then
+    AC_MSG_RESULT([yes])
+    AC_DEFINE_UNQUOTED(HAVE_GETHOSTBYNAME, 1,
+      [Define to 1 if you have the gethostbyname function.])
+    curl_cv_func_gethostbyname="yes"
+  else
+    AC_MSG_RESULT([no])
+    curl_cv_func_gethostbyname="no"
+  fi
+])
+
+
+dnl CURL_CHECK_FUNC_GETHOSTBYNAME_R
+dnl -------------------------------------------------
+dnl Verify if gethostbyname_r is available, prototyped,
+dnl and can be compiled. If all of these are true, and
+dnl usage has not been previously disallowed with
+dnl shell variable curl_disallow_gethostbyname_r, then
+dnl HAVE_GETHOSTBYNAME_R will be defined.
+
+AC_DEFUN([CURL_CHECK_FUNC_GETHOSTBYNAME_R], [
+  AC_REQUIRE([CURL_INCLUDES_NETDB])dnl
+  #
+  tst_links_gethostbyname_r="unknown"
+  tst_proto_gethostbyname_r="unknown"
+  tst_compi_gethostbyname_r="unknown"
+  tst_allow_gethostbyname_r="unknown"
+  tst_nargs_gethostbyname_r="unknown"
+  #
+  AC_MSG_CHECKING([if gethostbyname_r can be linked])
+  AC_LINK_IFELSE([
+    AC_LANG_FUNC_LINK_TRY([gethostbyname_r])
+  ],[
+    AC_MSG_RESULT([yes])
+    tst_links_gethostbyname_r="yes"
+  ],[
+    AC_MSG_RESULT([no])
+    tst_links_gethostbyname_r="no"
+  ])
+  #
+  if test "$tst_links_gethostbyname_r" = "yes"; then
+    AC_MSG_CHECKING([if gethostbyname_r is prototyped])
+    AC_EGREP_CPP([gethostbyname_r],[
+      $curl_includes_netdb
+    ],[
+      AC_MSG_RESULT([yes])
+      tst_proto_gethostbyname_r="yes"
+    ],[
+      AC_MSG_RESULT([no])
+      tst_proto_gethostbyname_r="no"
+    ])
+  fi
+  #
+  if test "$tst_proto_gethostbyname_r" = "yes"; then
+    if test "$tst_nargs_gethostbyname_r" = "unknown"; then
+      AC_MSG_CHECKING([if gethostbyname_r takes 3 args.])
+      AC_COMPILE_IFELSE([
+        AC_LANG_PROGRAM([[
+          $curl_includes_netdb
+        ]],[[
+          if(0 != gethostbyname_r(0, 0, 0))
+            return 1;
+        ]])
+      ],[
+        AC_MSG_RESULT([yes])
+        tst_compi_gethostbyname_r="yes"
+        tst_nargs_gethostbyname_r="3"
+      ],[
+        AC_MSG_RESULT([no])
+        tst_compi_gethostbyname_r="no"
+      ])
+    fi
+    if test "$tst_nargs_gethostbyname_r" = "unknown"; then
+      AC_MSG_CHECKING([if gethostbyname_r takes 5 args.])
+      AC_COMPILE_IFELSE([
+        AC_LANG_PROGRAM([[
+          $curl_includes_netdb
+        ]],[[
+          if(0 != gethostbyname_r(0, 0, 0, 0, 0))
+            return 1;
+        ]])
+      ],[
+        AC_MSG_RESULT([yes])
+        tst_compi_gethostbyname_r="yes"
+        tst_nargs_gethostbyname_r="5"
+      ],[
+        AC_MSG_RESULT([no])
+        tst_compi_gethostbyname_r="no"
+      ])
+    fi
+    if test "$tst_nargs_gethostbyname_r" = "unknown"; then
+      AC_MSG_CHECKING([if gethostbyname_r takes 6 args.])
+      AC_COMPILE_IFELSE([
+        AC_LANG_PROGRAM([[
+          $curl_includes_netdb
+        ]],[[
+          if(0 != gethostbyname_r(0, 0, 0, 0, 0, 0))
+            return 1;
+        ]])
+      ],[
+        AC_MSG_RESULT([yes])
+        tst_compi_gethostbyname_r="yes"
+        tst_nargs_gethostbyname_r="6"
+      ],[
+        AC_MSG_RESULT([no])
+        tst_compi_gethostbyname_r="no"
+      ])
+    fi
+    AC_MSG_CHECKING([if gethostbyname_r is compilable])
+    if test "$tst_compi_gethostbyname_r" = "yes"; then
+      AC_MSG_RESULT([yes])
+    else
+      AC_MSG_RESULT([no])
+    fi
+  fi
+  #
+  if test "$tst_compi_gethostbyname_r" = "yes"; then
+    AC_MSG_CHECKING([if gethostbyname_r usage allowed])
+    if test "x$curl_disallow_gethostbyname_r" != "xyes"; then
+      AC_MSG_RESULT([yes])
+      tst_allow_gethostbyname_r="yes"
+    else
+      AC_MSG_RESULT([no])
+      tst_allow_gethostbyname_r="no"
+    fi
+  fi
+  #
+  AC_MSG_CHECKING([if gethostbyname_r might be used])
+  if test "$tst_links_gethostbyname_r" = "yes" &&
+     test "$tst_proto_gethostbyname_r" = "yes" &&
+     test "$tst_compi_gethostbyname_r" = "yes" &&
+     test "$tst_allow_gethostbyname_r" = "yes"; then
+    AC_MSG_RESULT([yes])
+    AC_DEFINE_UNQUOTED(HAVE_GETHOSTBYNAME_R, 1,
+      [Define to 1 if you have the gethostbyname_r function.])
+    dnl AC_DEFINE_UNQUOTED(GETHOSTBYNAME_R_ARGS, $tst_nargs_gethostbyname_r,
+    dnl   [Specifies the number of arguments to gethostbyname_r])
+    #
+    if test "$tst_nargs_gethostbyname_r" -eq "3"; then
+      AC_DEFINE(HAVE_GETHOSTBYNAME_R_3, 1, [gethostbyname_r() takes 3 args])
+    elif test "$tst_nargs_gethostbyname_r" -eq "5"; then
+      AC_DEFINE(HAVE_GETHOSTBYNAME_R_5, 1, [gethostbyname_r() takes 5 args])
+    elif test "$tst_nargs_gethostbyname_r" -eq "6"; then
+      AC_DEFINE(HAVE_GETHOSTBYNAME_R_6, 1, [gethostbyname_r() takes 6 args])
+    fi
+    #
+    curl_cv_func_gethostbyname_r="yes"
+  else
+    AC_MSG_RESULT([no])
+    curl_cv_func_gethostbyname_r="no"
+  fi
+])
+
+
+dnl CURL_CHECK_FUNC_GETHOSTNAME
+dnl -------------------------------------------------
+dnl Verify if gethostname is available, prototyped, and
+dnl can be compiled. If all of these are true, and
+dnl usage has not been previously disallowed with
+dnl shell variable curl_disallow_gethostname, then
+dnl HAVE_GETHOSTNAME will be defined.
+
+AC_DEFUN([CURL_CHECK_FUNC_GETHOSTNAME], [
+  AC_REQUIRE([CURL_INCLUDES_WINSOCK2])dnl
+  AC_REQUIRE([CURL_INCLUDES_UNISTD])dnl
+  AC_REQUIRE([CURL_PREPROCESS_CALLCONV])dnl
+  #
+  tst_links_gethostname="unknown"
+  tst_proto_gethostname="unknown"
+  tst_compi_gethostname="unknown"
+  tst_allow_gethostname="unknown"
+  #
+  AC_MSG_CHECKING([if gethostname can be linked])
+  AC_LINK_IFELSE([
+    AC_LANG_PROGRAM([[
+      $curl_includes_winsock2
+      $curl_includes_unistd
+    ]],[[
+      if(0 != gethostname(0, 0))
+        return 1;
+    ]])
+  ],[
+    AC_MSG_RESULT([yes])
+    tst_links_gethostname="yes"
+  ],[
+    AC_MSG_RESULT([no])
+    tst_links_gethostname="no"
+  ])
+  #
+  if test "$tst_links_gethostname" = "yes"; then
+    AC_MSG_CHECKING([if gethostname is prototyped])
+    AC_EGREP_CPP([gethostname],[
+      $curl_includes_winsock2
+      $curl_includes_unistd
+    ],[
+      AC_MSG_RESULT([yes])
+      tst_proto_gethostname="yes"
+    ],[
+      AC_MSG_RESULT([no])
+      tst_proto_gethostname="no"
+    ])
+  fi
+  #
+  if test "$tst_proto_gethostname" = "yes"; then
+    AC_MSG_CHECKING([if gethostname is compilable])
+    AC_COMPILE_IFELSE([
+      AC_LANG_PROGRAM([[
+        $curl_includes_winsock2
+        $curl_includes_unistd
+      ]],[[
+        if(0 != gethostname(0, 0))
+          return 1;
+      ]])
+    ],[
+      AC_MSG_RESULT([yes])
+      tst_compi_gethostname="yes"
+    ],[
+      AC_MSG_RESULT([no])
+      tst_compi_gethostname="no"
+    ])
+  fi
+  #
+  if test "$tst_compi_gethostname" = "yes"; then
+    AC_MSG_CHECKING([for gethostname arg 2 data type])
+    tst_gethostname_type_arg2="unknown"
+    for tst_arg1 in 'char *' 'unsigned char *' 'void *'; do
+      for tst_arg2 in 'int' 'unsigned int' 'size_t'; do
+        if test "$tst_gethostname_type_arg2" = "unknown"; then
+          AC_COMPILE_IFELSE([
+            AC_LANG_PROGRAM([[
+              $curl_includes_winsock2
+              $curl_includes_unistd
+              $curl_preprocess_callconv
+              extern int FUNCALLCONV gethostname($tst_arg1, $tst_arg2);
+            ]],[[
+              if(0 != gethostname(0, 0))
+                return 1;
+            ]])
+          ],[
+            tst_gethostname_type_arg2="$tst_arg2"
+          ])
+        fi
+      done
+    done
+    AC_MSG_RESULT([$tst_gethostname_type_arg2])
+    if test "$tst_gethostname_type_arg2" != "unknown"; then
+      AC_DEFINE_UNQUOTED(GETHOSTNAME_TYPE_ARG2, $tst_gethostname_type_arg2,
+        [Define to the type of arg 2 for gethostname.])
+    fi
+  fi
+  #
+  if test "$tst_compi_gethostname" = "yes"; then
+    AC_MSG_CHECKING([if gethostname usage allowed])
+    if test "x$curl_disallow_gethostname" != "xyes"; then
+      AC_MSG_RESULT([yes])
+      tst_allow_gethostname="yes"
+    else
+      AC_MSG_RESULT([no])
+      tst_allow_gethostname="no"
+    fi
+  fi
+  #
+  AC_MSG_CHECKING([if gethostname might be used])
+  if test "$tst_links_gethostname" = "yes" &&
+     test "$tst_proto_gethostname" = "yes" &&
+     test "$tst_compi_gethostname" = "yes" &&
+     test "$tst_allow_gethostname" = "yes"; then
+    AC_MSG_RESULT([yes])
+    AC_DEFINE_UNQUOTED(HAVE_GETHOSTNAME, 1,
+      [Define to 1 if you have the gethostname function.])
+    curl_cv_func_gethostname="yes"
+  else
+    AC_MSG_RESULT([no])
+    curl_cv_func_gethostname="no"
+  fi
+])
+
+
+dnl CURL_CHECK_FUNC_GETIFADDRS
+dnl -------------------------------------------------
+dnl Verify if getifaddrs is available, prototyped, can
+dnl be compiled and seems to work. If all of these are
+dnl true, and usage has not been previously disallowed
+dnl with shell variable curl_disallow_getifaddrs, then
+dnl HAVE_GETIFADDRS will be defined.
+
+AC_DEFUN([CURL_CHECK_FUNC_GETIFADDRS], [
+  AC_REQUIRE([CURL_INCLUDES_STDLIB])dnl
+  AC_REQUIRE([CURL_INCLUDES_IFADDRS])dnl
+  #
+  tst_links_getifaddrs="unknown"
+  tst_proto_getifaddrs="unknown"
+  tst_compi_getifaddrs="unknown"
+  tst_works_getifaddrs="unknown"
+  tst_allow_getifaddrs="unknown"
+  #
+  AC_MSG_CHECKING([if getifaddrs can be linked])
+  AC_LINK_IFELSE([
+    AC_LANG_FUNC_LINK_TRY([getifaddrs])
+  ],[
+    AC_MSG_RESULT([yes])
+    tst_links_getifaddrs="yes"
+  ],[
+    AC_MSG_RESULT([no])
+    tst_links_getifaddrs="no"
+  ])
+  #
+  if test "$tst_links_getifaddrs" = "yes"; then
+    AC_MSG_CHECKING([if getifaddrs is prototyped])
+    AC_EGREP_CPP([getifaddrs],[
+      $curl_includes_ifaddrs
+    ],[
+      AC_MSG_RESULT([yes])
+      tst_proto_getifaddrs="yes"
+    ],[
+      AC_MSG_RESULT([no])
+      tst_proto_getifaddrs="no"
+    ])
+  fi
+  #
+  if test "$tst_proto_getifaddrs" = "yes"; then
+    AC_MSG_CHECKING([if getifaddrs is compilable])
+    AC_COMPILE_IFELSE([
+      AC_LANG_PROGRAM([[
+        $curl_includes_ifaddrs
+      ]],[[
+        if(0 != getifaddrs(0))
+          return 1;
+      ]])
+    ],[
+      AC_MSG_RESULT([yes])
+      tst_compi_getifaddrs="yes"
+    ],[
+      AC_MSG_RESULT([no])
+      tst_compi_getifaddrs="no"
+    ])
+  fi
+  #
+  dnl only do runtime verification when not cross-compiling
+  if test "x$cross_compiling" != "xyes" &&
+    test "$tst_compi_getifaddrs" = "yes"; then
+    AC_MSG_CHECKING([if getifaddrs seems to work])
+    AC_RUN_IFELSE([
+      AC_LANG_PROGRAM([[
+        $curl_includes_stdlib
+        $curl_includes_ifaddrs
+      ]],[[
+        struct ifaddrs *ifa = 0;
+        int error;
+
+        error = getifaddrs(&ifa);
+        if(error || !ifa)
+          exit(1); /* fail */
+        else
+          exit(0);
+      ]])
+    ],[
+      AC_MSG_RESULT([yes])
+      tst_works_getifaddrs="yes"
+    ],[
+      AC_MSG_RESULT([no])
+      tst_works_getifaddrs="no"
+    ])
+  fi
+  #
+  if test "$tst_compi_getifaddrs" = "yes" &&
+    test "$tst_works_getifaddrs" != "no"; then
+    AC_MSG_CHECKING([if getifaddrs usage allowed])
+    if test "x$curl_disallow_getifaddrs" != "xyes"; then
+      AC_MSG_RESULT([yes])
+      tst_allow_getifaddrs="yes"
+    else
+      AC_MSG_RESULT([no])
+      tst_allow_getifaddrs="no"
+    fi
+  fi
+  #
+  AC_MSG_CHECKING([if getifaddrs might be used])
+  if test "$tst_links_getifaddrs" = "yes" &&
+     test "$tst_proto_getifaddrs" = "yes" &&
+     test "$tst_compi_getifaddrs" = "yes" &&
+     test "$tst_allow_getifaddrs" = "yes" &&
+     test "$tst_works_getifaddrs" != "no"; then
+    AC_MSG_RESULT([yes])
+    AC_DEFINE_UNQUOTED(HAVE_GETIFADDRS, 1,
+      [Define to 1 if you have a working getifaddrs function.])
+    curl_cv_func_getifaddrs="yes"
+  else
+    AC_MSG_RESULT([no])
+    curl_cv_func_getifaddrs="no"
+  fi
+])
+
+
+dnl CURL_CHECK_FUNC_GETSERVBYPORT_R
+dnl -------------------------------------------------
+dnl Verify if getservbyport_r is available, prototyped,
+dnl and can be compiled. If all of these are true, and
+dnl usage has not been previously disallowed with
+dnl shell variable curl_disallow_getservbyport_r, then
+dnl HAVE_GETSERVBYPORT_R will be defined.
+
+AC_DEFUN([CURL_CHECK_FUNC_GETSERVBYPORT_R], [
+  AC_REQUIRE([CURL_INCLUDES_NETDB])dnl
+  #
+  tst_links_getservbyport_r="unknown"
+  tst_proto_getservbyport_r="unknown"
+  tst_compi_getservbyport_r="unknown"
+  tst_allow_getservbyport_r="unknown"
+  tst_nargs_getservbyport_r="unknown"
+  #
+  AC_MSG_CHECKING([if getservbyport_r can be linked])
+  AC_LINK_IFELSE([
+    AC_LANG_FUNC_LINK_TRY([getservbyport_r])
+  ],[
+    AC_MSG_RESULT([yes])
+    tst_links_getservbyport_r="yes"
+  ],[
+    AC_MSG_RESULT([no])
+    tst_links_getservbyport_r="no"
+  ])
+  #
+  if test "$tst_links_getservbyport_r" = "yes"; then
+    AC_MSG_CHECKING([if getservbyport_r is prototyped])
+    AC_EGREP_CPP([getservbyport_r],[
+      $curl_includes_netdb
+    ],[
+      AC_MSG_RESULT([yes])
+      tst_proto_getservbyport_r="yes"
+    ],[
+      AC_MSG_RESULT([no])
+      tst_proto_getservbyport_r="no"
+    ])
+  fi
+  #
+  if test "$tst_proto_getservbyport_r" = "yes"; then
+    if test "$tst_nargs_getservbyport_r" = "unknown"; then
+      AC_MSG_CHECKING([if getservbyport_r takes 4 args.])
+      AC_COMPILE_IFELSE([
+        AC_LANG_PROGRAM([[
+          $curl_includes_netdb
+        ]],[[
+          if(0 != getservbyport_r(0, 0, 0, 0))
+            return 1;
+        ]])
+      ],[
+        AC_MSG_RESULT([yes])
+        tst_compi_getservbyport_r="yes"
+        tst_nargs_getservbyport_r="4"
+      ],[
+        AC_MSG_RESULT([no])
+        tst_compi_getservbyport_r="no"
+      ])
+    fi
+    if test "$tst_nargs_getservbyport_r" = "unknown"; then
+      AC_MSG_CHECKING([if getservbyport_r takes 5 args.])
+      AC_COMPILE_IFELSE([
+        AC_LANG_PROGRAM([[
+          $curl_includes_netdb
+        ]],[[
+          if(0 != getservbyport_r(0, 0, 0, 0, 0))
+            return 1;
+        ]])
+      ],[
+        AC_MSG_RESULT([yes])
+        tst_compi_getservbyport_r="yes"
+        tst_nargs_getservbyport_r="5"
+      ],[
+        AC_MSG_RESULT([no])
+        tst_compi_getservbyport_r="no"
+      ])
+    fi
+    if test "$tst_nargs_getservbyport_r" = "unknown"; then
+      AC_MSG_CHECKING([if getservbyport_r takes 6 args.])
+      AC_COMPILE_IFELSE([
+        AC_LANG_PROGRAM([[
+          $curl_includes_netdb
+        ]],[[
+          if(0 != getservbyport_r(0, 0, 0, 0, 0, 0))
+            return 1;
+        ]])
+      ],[
+        AC_MSG_RESULT([yes])
+        tst_compi_getservbyport_r="yes"
+        tst_nargs_getservbyport_r="6"
+      ],[
+        AC_MSG_RESULT([no])
+        tst_compi_getservbyport_r="no"
+      ])
+    fi
+    AC_MSG_CHECKING([if getservbyport_r is compilable])
+    if test "$tst_compi_getservbyport_r" = "yes"; then
+      AC_MSG_RESULT([yes])
+    else
+      AC_MSG_RESULT([no])
+    fi
+  fi
+  #
+  if test "$tst_compi_getservbyport_r" = "yes"; then
+    AC_MSG_CHECKING([if getservbyport_r usage allowed])
+    if test "x$curl_disallow_getservbyport_r" != "xyes"; then
+      AC_MSG_RESULT([yes])
+      tst_allow_getservbyport_r="yes"
+    else
+      AC_MSG_RESULT([no])
+      tst_allow_getservbyport_r="no"
+    fi
+  fi
+  #
+  AC_MSG_CHECKING([if getservbyport_r might be used])
+  if test "$tst_links_getservbyport_r" = "yes" &&
+     test "$tst_proto_getservbyport_r" = "yes" &&
+     test "$tst_compi_getservbyport_r" = "yes" &&
+     test "$tst_allow_getservbyport_r" = "yes"; then
+    AC_MSG_RESULT([yes])
+    AC_DEFINE_UNQUOTED(HAVE_GETSERVBYPORT_R, 1,
+      [Define to 1 if you have the getservbyport_r function.])
+    AC_DEFINE_UNQUOTED(GETSERVBYPORT_R_ARGS, $tst_nargs_getservbyport_r,
+      [Specifies the number of arguments to getservbyport_r])
+    if test "$tst_nargs_getservbyport_r" -eq "4"; then
+      AC_DEFINE(GETSERVBYPORT_R_BUFSIZE, sizeof(struct servent_data),
+        [Specifies the size of the buffer to pass to getservbyport_r])
+    else
+      AC_DEFINE(GETSERVBYPORT_R_BUFSIZE, 4096,
+        [Specifies the size of the buffer to pass to getservbyport_r])
+    fi
+    curl_cv_func_getservbyport_r="yes"
+  else
+    AC_MSG_RESULT([no])
+    curl_cv_func_getservbyport_r="no"
+  fi
+])
+
+
+dnl CURL_CHECK_FUNC_GETXATTR
+dnl -------------------------------------------------
+dnl Verify if getxattr is available, prototyped, and
+dnl can be compiled. If all of these are true, and
+dnl usage has not been previously disallowed with
+dnl shell variable curl_disallow_getxattr, then
+dnl HAVE_GETXATTR will be defined.
+
+AC_DEFUN([CURL_CHECK_FUNC_GETXATTR], [
+  AC_REQUIRE([CURL_INCLUDES_SYS_XATTR])dnl
+  #
+  tst_links_getxattr="unknown"
+  tst_proto_getxattr="unknown"
+  tst_compi_getxattr="unknown"
+  tst_allow_getxattr="unknown"
+  tst_nargs_getxattr="unknown"
+  #
+  AC_MSG_CHECKING([if getxattr can be linked])
+  AC_LINK_IFELSE([
+    AC_LANG_FUNC_LINK_TRY([getxattr])
+  ],[
+    AC_MSG_RESULT([yes])
+    tst_links_getxattr="yes"
+  ],[
+    AC_MSG_RESULT([no])
+    tst_links_getxattr="no"
+  ])
+  #
+  if test "$tst_links_getxattr" = "yes"; then
+    AC_MSG_CHECKING([if getxattr is prototyped])
+    AC_EGREP_CPP([getxattr],[
+      $curl_includes_sys_xattr
+    ],[
+      AC_MSG_RESULT([yes])
+      tst_proto_getxattr="yes"
+    ],[
+      AC_MSG_RESULT([no])
+      tst_proto_getxattr="no"
+    ])
+  fi
+  #
+  if test "$tst_proto_getxattr" = "yes"; then
+    if test "$tst_nargs_getxattr" = "unknown"; then
+      AC_MSG_CHECKING([if getxattr takes 4 args.])
+      AC_COMPILE_IFELSE([
+        AC_LANG_PROGRAM([[
+          $curl_includes_sys_xattr
+        ]],[[
+          if(0 != getxattr(0, 0, 0, 0))
+            return 1;
+        ]])
+      ],[
+        AC_MSG_RESULT([yes])
+        tst_compi_getxattr="yes"
+        tst_nargs_getxattr="4"
+      ],[
+        AC_MSG_RESULT([no])
+        tst_compi_getxattr="no"
+      ])
+    fi
+    if test "$tst_nargs_getxattr" = "unknown"; then
+      AC_MSG_CHECKING([if getxattr takes 6 args.])
+      AC_COMPILE_IFELSE([
+        AC_LANG_PROGRAM([[
+          $curl_includes_sys_xattr
+        ]],[[
+          if(0 != getxattr(0, 0, 0, 0, 0, 0))
+            return 1;
+        ]])
+      ],[
+        AC_MSG_RESULT([yes])
+        tst_compi_getxattr="yes"
+        tst_nargs_getxattr="6"
+      ],[
+        AC_MSG_RESULT([no])
+        tst_compi_getxattr="no"
+      ])
+    fi
+    AC_MSG_CHECKING([if getxattr is compilable])
+    if test "$tst_compi_getxattr" = "yes"; then
+      AC_MSG_RESULT([yes])
+    else
+      AC_MSG_RESULT([no])
+    fi
+  fi
+  #
+  if test "$tst_compi_getxattr" = "yes"; then
+    AC_MSG_CHECKING([if getxattr usage allowed])
+    if test "x$curl_disallow_getxattr" != "xyes"; then
+      AC_MSG_RESULT([yes])
+      tst_allow_getxattr="yes"
+    else
+      AC_MSG_RESULT([no])
+      tst_allow_getxattr="no"
+    fi
+  fi
+  #
+  AC_MSG_CHECKING([if getxattr might be used])
+  if test "$tst_links_getxattr" = "yes" &&
+     test "$tst_proto_getxattr" = "yes" &&
+     test "$tst_compi_getxattr" = "yes" &&
+     test "$tst_allow_getxattr" = "yes"; then
+    AC_MSG_RESULT([yes])
+    AC_DEFINE_UNQUOTED(HAVE_GETXATTR, 1,
+      [Define to 1 if you have the getxattr function.])
+    dnl AC_DEFINE_UNQUOTED(GETXATTR_ARGS, $tst_nargs_getxattr,
+    dnl   [Specifies the number of arguments to getxattr])
+    #
+    if test "$tst_nargs_getxattr" -eq "4"; then
+      AC_DEFINE(HAVE_GETXATTR_4, 1, [getxattr() takes 4 args])
+    elif test "$tst_nargs_getxattr" -eq "6"; then
+      AC_DEFINE(HAVE_GETXATTR_6, 1, [getxattr() takes 6 args])
+    fi
+    #
+    curl_cv_func_getxattr="yes"
+  else
+    AC_MSG_RESULT([no])
+    curl_cv_func_getxattr="no"
+  fi
+])
+
+
+dnl CURL_CHECK_FUNC_GMTIME_R
+dnl -------------------------------------------------
+dnl Verify if gmtime_r is available, prototyped, can
+dnl be compiled and seems to work. If all of these are
+dnl true, and usage has not been previously disallowed
+dnl with shell variable curl_disallow_gmtime_r, then
+dnl HAVE_GMTIME_R will be defined.
+
+AC_DEFUN([CURL_CHECK_FUNC_GMTIME_R], [
+  AC_REQUIRE([CURL_INCLUDES_STDLIB])dnl
+  AC_REQUIRE([CURL_INCLUDES_TIME])dnl
+  #
+  tst_links_gmtime_r="unknown"
+  tst_proto_gmtime_r="unknown"
+  tst_compi_gmtime_r="unknown"
+  tst_works_gmtime_r="unknown"
+  tst_allow_gmtime_r="unknown"
+  #
+  AC_MSG_CHECKING([if gmtime_r can be linked])
+  AC_LINK_IFELSE([
+    AC_LANG_FUNC_LINK_TRY([gmtime_r])
+  ],[
+    AC_MSG_RESULT([yes])
+    tst_links_gmtime_r="yes"
+  ],[
+    AC_MSG_RESULT([no])
+    tst_links_gmtime_r="no"
+  ])
+  #
+  if test "$tst_links_gmtime_r" = "yes"; then
+    AC_MSG_CHECKING([if gmtime_r is prototyped])
+    AC_EGREP_CPP([gmtime_r],[
+      $curl_includes_time
+    ],[
+      AC_MSG_RESULT([yes])
+      tst_proto_gmtime_r="yes"
+    ],[
+      AC_MSG_RESULT([no])
+      tst_proto_gmtime_r="no"
+    ])
+  fi
+  #
+  if test "$tst_proto_gmtime_r" = "yes"; then
+    AC_MSG_CHECKING([if gmtime_r is compilable])
+    AC_COMPILE_IFELSE([
+      AC_LANG_PROGRAM([[
+        $curl_includes_time
+      ]],[[
+        if(0 != gmtime_r(0, 0))
+          return 1;
+      ]])
+    ],[
+      AC_MSG_RESULT([yes])
+      tst_compi_gmtime_r="yes"
+    ],[
+      AC_MSG_RESULT([no])
+      tst_compi_gmtime_r="no"
+    ])
+  fi
+  #
+  dnl only do runtime verification when not cross-compiling
+  if test "x$cross_compiling" != "xyes" &&
+    test "$tst_compi_gmtime_r" = "yes"; then
+    AC_MSG_CHECKING([if gmtime_r seems to work])
+    AC_RUN_IFELSE([
+      AC_LANG_PROGRAM([[
+        $curl_includes_stdlib
+        $curl_includes_time
+      ]],[[
+        time_t local = 1170352587;
+        struct tm *gmt = 0;
+        struct tm result;
+        gmt = gmtime_r(&local, &result);
+        if(gmt)
+          exit(0);
+        else
+          exit(1);
+      ]])
+    ],[
+      AC_MSG_RESULT([yes])
+      tst_works_gmtime_r="yes"
+    ],[
+      AC_MSG_RESULT([no])
+      tst_works_gmtime_r="no"
+    ])
+  fi
+  #
+  if test "$tst_compi_gmtime_r" = "yes" &&
+    test "$tst_works_gmtime_r" != "no"; then
+    AC_MSG_CHECKING([if gmtime_r usage allowed])
+    if test "x$curl_disallow_gmtime_r" != "xyes"; then
+      AC_MSG_RESULT([yes])
+      tst_allow_gmtime_r="yes"
+    else
+      AC_MSG_RESULT([no])
+      tst_allow_gmtime_r="no"
+    fi
+  fi
+  #
+  AC_MSG_CHECKING([if gmtime_r might be used])
+  if test "$tst_links_gmtime_r" = "yes" &&
+     test "$tst_proto_gmtime_r" = "yes" &&
+     test "$tst_compi_gmtime_r" = "yes" &&
+     test "$tst_allow_gmtime_r" = "yes" &&
+     test "$tst_works_gmtime_r" != "no"; then
+    AC_MSG_RESULT([yes])
+    AC_DEFINE_UNQUOTED(HAVE_GMTIME_R, 1,
+      [Define to 1 if you have a working gmtime_r function.])
+    curl_cv_func_gmtime_r="yes"
+  else
+    AC_MSG_RESULT([no])
+    curl_cv_func_gmtime_r="no"
+  fi
+])
+
+
+dnl CURL_CHECK_FUNC_INET_NTOA_R
+dnl -------------------------------------------------
+dnl Verify if inet_ntoa_r is available, prototyped,
+dnl and can be compiled. If all of these are true, and
+dnl usage has not been previously disallowed with
+dnl shell variable curl_disallow_inet_ntoa_r, then
+dnl HAVE_INET_NTOA_R will be defined.
+
+AC_DEFUN([CURL_CHECK_FUNC_INET_NTOA_R], [
+  AC_REQUIRE([CURL_INCLUDES_ARPA_INET])dnl
+  #
+  tst_links_inet_ntoa_r="unknown"
+  tst_proto_inet_ntoa_r="unknown"
+  tst_compi_inet_ntoa_r="unknown"
+  tst_allow_inet_ntoa_r="unknown"
+  tst_nargs_inet_ntoa_r="unknown"
+  #
+  AC_MSG_CHECKING([if inet_ntoa_r can be linked])
+  AC_LINK_IFELSE([
+    AC_LANG_FUNC_LINK_TRY([inet_ntoa_r])
+  ],[
+    AC_MSG_RESULT([yes])
+    tst_links_inet_ntoa_r="yes"
+  ],[
+    AC_MSG_RESULT([no])
+    tst_links_inet_ntoa_r="no"
+  ])
+  #
+  if test "$tst_links_inet_ntoa_r" = "yes"; then
+    AC_MSG_CHECKING([if inet_ntoa_r is prototyped])
+    AC_EGREP_CPP([inet_ntoa_r],[
+      $curl_includes_arpa_inet
+    ],[
+      AC_MSG_RESULT([yes])
+      tst_proto_inet_ntoa_r="yes"
+    ],[
+      AC_MSG_RESULT([no])
+      tst_proto_inet_ntoa_r="no"
+    ])
+  fi
+  #
+  if test "$tst_proto_inet_ntoa_r" = "yes"; then
+    if test "$tst_nargs_inet_ntoa_r" = "unknown"; then
+      AC_MSG_CHECKING([if inet_ntoa_r takes 2 args.])
+      AC_COMPILE_IFELSE([
+        AC_LANG_PROGRAM([[
+          $curl_includes_arpa_inet
+        ]],[[
+          struct in_addr addr;
+          if(0 != inet_ntoa_r(addr, 0))
+            return 1;
+        ]])
+      ],[
+        AC_MSG_RESULT([yes])
+        tst_compi_inet_ntoa_r="yes"
+        tst_nargs_inet_ntoa_r="2"
+      ],[
+        AC_MSG_RESULT([no])
+        tst_compi_inet_ntoa_r="no"
+      ])
+    fi
+    if test "$tst_nargs_inet_ntoa_r" = "unknown"; then
+      AC_MSG_CHECKING([if inet_ntoa_r takes 3 args.])
+      AC_COMPILE_IFELSE([
+        AC_LANG_PROGRAM([[
+          $curl_includes_arpa_inet
+        ]],[[
+          struct in_addr addr;
+          if(0 != inet_ntoa_r(addr, 0, 0))
+            return 1;
+        ]])
+      ],[
+        AC_MSG_RESULT([yes])
+        tst_compi_inet_ntoa_r="yes"
+        tst_nargs_inet_ntoa_r="3"
+      ],[
+        AC_MSG_RESULT([no])
+        tst_compi_inet_ntoa_r="no"
+      ])
+    fi
+    AC_MSG_CHECKING([if inet_ntoa_r is compilable])
+    if test "$tst_compi_inet_ntoa_r" = "yes"; then
+      AC_MSG_RESULT([yes])
+    else
+      AC_MSG_RESULT([no])
+    fi
+  fi
+  #
+  if test "$tst_compi_inet_ntoa_r" = "yes"; then
+    AC_MSG_CHECKING([if inet_ntoa_r usage allowed])
+    if test "x$curl_disallow_inet_ntoa_r" != "xyes"; then
+      AC_MSG_RESULT([yes])
+      tst_allow_inet_ntoa_r="yes"
+    else
+      AC_MSG_RESULT([no])
+      tst_allow_inet_ntoa_r="no"
+    fi
+  fi
+  #
+  AC_MSG_CHECKING([if inet_ntoa_r might be used])
+  if test "$tst_links_inet_ntoa_r" = "yes" &&
+     test "$tst_proto_inet_ntoa_r" = "yes" &&
+     test "$tst_compi_inet_ntoa_r" = "yes" &&
+     test "$tst_allow_inet_ntoa_r" = "yes"; then
+    AC_MSG_RESULT([yes])
+    AC_DEFINE_UNQUOTED(HAVE_INET_NTOA_R, 1,
+      [Define to 1 if you have the inet_ntoa_r function.])
+    dnl AC_DEFINE_UNQUOTED(INET_NTOA_R_ARGS, $tst_nargs_inet_ntoa_r,
+    dnl   [Specifies the number of arguments to inet_ntoa_r])
+    #
+    if test "$tst_nargs_inet_ntoa_r" -eq "2"; then
+      AC_DEFINE(HAVE_INET_NTOA_R_2, 1, [inet_ntoa_r() takes 2 args])
+    elif test "$tst_nargs_inet_ntoa_r" -eq "3"; then
+      AC_DEFINE(HAVE_INET_NTOA_R_3, 1, [inet_ntoa_r() takes 3 args])
+    fi
+    #
+    curl_cv_func_inet_ntoa_r="yes"
+  else
+    AC_MSG_RESULT([no])
+    curl_cv_func_inet_ntoa_r="no"
+  fi
+])
+
+
+dnl CURL_CHECK_FUNC_INET_NTOP
+dnl -------------------------------------------------
+dnl Verify if inet_ntop is available, prototyped, can
+dnl be compiled and seems to work. If all of these are
+dnl true, and usage has not been previously disallowed
+dnl with shell variable curl_disallow_inet_ntop, then
+dnl HAVE_INET_NTOP will be defined.
+
+AC_DEFUN([CURL_CHECK_FUNC_INET_NTOP], [
+  AC_REQUIRE([CURL_INCLUDES_STDLIB])dnl
+  AC_REQUIRE([CURL_INCLUDES_ARPA_INET])dnl
+  AC_REQUIRE([CURL_INCLUDES_STRING])dnl
+  #
+  tst_links_inet_ntop="unknown"
+  tst_proto_inet_ntop="unknown"
+  tst_compi_inet_ntop="unknown"
+  tst_works_inet_ntop="unknown"
+  tst_allow_inet_ntop="unknown"
+  #
+  AC_MSG_CHECKING([if inet_ntop can be linked])
+  AC_LINK_IFELSE([
+    AC_LANG_FUNC_LINK_TRY([inet_ntop])
+  ],[
+    AC_MSG_RESULT([yes])
+    tst_links_inet_ntop="yes"
+  ],[
+    AC_MSG_RESULT([no])
+    tst_links_inet_ntop="no"
+  ])
+  #
+  if test "$tst_links_inet_ntop" = "yes"; then
+    AC_MSG_CHECKING([if inet_ntop is prototyped])
+    AC_EGREP_CPP([inet_ntop],[
+      $curl_includes_arpa_inet
+    ],[
+      AC_MSG_RESULT([yes])
+      tst_proto_inet_ntop="yes"
+    ],[
+      AC_MSG_RESULT([no])
+      tst_proto_inet_ntop="no"
+    ])
+  fi
+  #
+  if test "$tst_proto_inet_ntop" = "yes"; then
+    AC_MSG_CHECKING([if inet_ntop is compilable])
+    AC_COMPILE_IFELSE([
+      AC_LANG_PROGRAM([[
+        $curl_includes_arpa_inet
+      ]],[[
+        if(0 != inet_ntop(0, 0, 0, 0))
+          return 1;
+      ]])
+    ],[
+      AC_MSG_RESULT([yes])
+      tst_compi_inet_ntop="yes"
+    ],[
+      AC_MSG_RESULT([no])
+      tst_compi_inet_ntop="no"
+    ])
+  fi
+  #
+  dnl only do runtime verification when not cross-compiling
+  if test "x$cross_compiling" != "xyes" &&
+    test "$tst_compi_inet_ntop" = "yes"; then
+    AC_MSG_CHECKING([if inet_ntop seems to work])
+    AC_RUN_IFELSE([
+      AC_LANG_PROGRAM([[
+        $curl_includes_stdlib
+        $curl_includes_arpa_inet
+        $curl_includes_string
+      ]],[[
+        char ipv6res[sizeof("ffff:ffff:ffff:ffff:ffff:ffff:255.255.255.255")];
+        char ipv4res[sizeof "255.255.255.255"];
+        unsigned char ipv6a[26];
+        unsigned char ipv4a[5];
+        char *ipv6ptr = 0;
+        char *ipv4ptr = 0;
+        /* - */
+        ipv4res[0] = '\0';
+        ipv4a[0] = 0xc0;
+        ipv4a[1] = 0xa8;
+        ipv4a[2] = 0x64;
+        ipv4a[3] = 0x01;
+        ipv4a[4] = 0x01;
+        /* - */
+        ipv4ptr = inet_ntop(AF_INET, ipv4a, ipv4res, sizeof(ipv4res));
+        if(!ipv4ptr)
+          exit(1); /* fail */
+        if(ipv4ptr != ipv4res)
+          exit(1); /* fail */
+        if(!ipv4ptr[0])
+          exit(1); /* fail */
+        if(memcmp(ipv4res, "192.168.100.1", 13) != 0)
+          exit(1); /* fail */
+        /* - */
+        ipv6res[0] = '\0';
+        memset(ipv6a, 0, sizeof(ipv6a));
+        ipv6a[0] = 0xfe;
+        ipv6a[1] = 0x80;
+        ipv6a[8] = 0x02;
+        ipv6a[9] = 0x14;
+        ipv6a[10] = 0x4f;
+        ipv6a[11] = 0xff;
+        ipv6a[12] = 0xfe;
+        ipv6a[13] = 0x0b;
+        ipv6a[14] = 0x76;
+        ipv6a[15] = 0xc8;
+        ipv6a[25] = 0x01;
+        /* - */
+        ipv6ptr = inet_ntop(AF_INET6, ipv6a, ipv6res, sizeof(ipv6res));
+        if(!ipv6ptr)
+          exit(1); /* fail */
+        if(ipv6ptr != ipv6res)
+          exit(1); /* fail */
+        if(!ipv6ptr[0])
+          exit(1); /* fail */
+        if(memcmp(ipv6res, "fe80::214:4fff:fe0b:76c8", 24) != 0)
+          exit(1); /* fail */
+        /* - */
+        exit(0);
+      ]])
+    ],[
+      AC_MSG_RESULT([yes])
+      tst_works_inet_ntop="yes"
+    ],[
+      AC_MSG_RESULT([no])
+      tst_works_inet_ntop="no"
+    ])
+  fi
+  #
+  if test "$tst_compi_inet_ntop" = "yes" &&
+    test "$tst_works_inet_ntop" != "no"; then
+    AC_MSG_CHECKING([if inet_ntop usage allowed])
+    if test "x$curl_disallow_inet_ntop" != "xyes"; then
+      AC_MSG_RESULT([yes])
+      tst_allow_inet_ntop="yes"
+    else
+      AC_MSG_RESULT([no])
+      tst_allow_inet_ntop="no"
+    fi
+  fi
+  #
+  AC_MSG_CHECKING([if inet_ntop might be used])
+  if test "$tst_links_inet_ntop" = "yes" &&
+     test "$tst_proto_inet_ntop" = "yes" &&
+     test "$tst_compi_inet_ntop" = "yes" &&
+     test "$tst_allow_inet_ntop" = "yes" &&
+     test "$tst_works_inet_ntop" != "no"; then
+    AC_MSG_RESULT([yes])
+    AC_DEFINE_UNQUOTED(HAVE_INET_NTOP, 1,
+      [Define to 1 if you have a IPv6 capable working inet_ntop function.])
+    curl_cv_func_inet_ntop="yes"
+  else
+    AC_MSG_RESULT([no])
+    curl_cv_func_inet_ntop="no"
+  fi
+])
+
+
+dnl CURL_CHECK_FUNC_INET_PTON
+dnl -------------------------------------------------
+dnl Verify if inet_pton is available, prototyped, can
+dnl be compiled and seems to work. If all of these are
+dnl true, and usage has not been previously disallowed
+dnl with shell variable curl_disallow_inet_pton, then
+dnl HAVE_INET_PTON will be defined.
+
+AC_DEFUN([CURL_CHECK_FUNC_INET_PTON], [
+  AC_REQUIRE([CURL_INCLUDES_STDLIB])dnl
+  AC_REQUIRE([CURL_INCLUDES_ARPA_INET])dnl
+  AC_REQUIRE([CURL_INCLUDES_STRING])dnl
+  #
+  tst_links_inet_pton="unknown"
+  tst_proto_inet_pton="unknown"
+  tst_compi_inet_pton="unknown"
+  tst_works_inet_pton="unknown"
+  tst_allow_inet_pton="unknown"
+  #
+  AC_MSG_CHECKING([if inet_pton can be linked])
+  AC_LINK_IFELSE([
+    AC_LANG_FUNC_LINK_TRY([inet_pton])
+  ],[
+    AC_MSG_RESULT([yes])
+    tst_links_inet_pton="yes"
+  ],[
+    AC_MSG_RESULT([no])
+    tst_links_inet_pton="no"
+  ])
+  #
+  if test "$tst_links_inet_pton" = "yes"; then
+    AC_MSG_CHECKING([if inet_pton is prototyped])
+    AC_EGREP_CPP([inet_pton],[
+      $curl_includes_arpa_inet
+    ],[
+      AC_MSG_RESULT([yes])
+      tst_proto_inet_pton="yes"
+    ],[
+      AC_MSG_RESULT([no])
+      tst_proto_inet_pton="no"
+    ])
+  fi
+  #
+  if test "$tst_proto_inet_pton" = "yes"; then
+    AC_MSG_CHECKING([if inet_pton is compilable])
+    AC_COMPILE_IFELSE([
+      AC_LANG_PROGRAM([[
+        $curl_includes_arpa_inet
+      ]],[[
+        if(0 != inet_pton(0, 0, 0))
+          return 1;
+      ]])
+    ],[
+      AC_MSG_RESULT([yes])
+      tst_compi_inet_pton="yes"
+    ],[
+      AC_MSG_RESULT([no])
+      tst_compi_inet_pton="no"
+    ])
+  fi
+  #
+  dnl only do runtime verification when not cross-compiling
+  if test "x$cross_compiling" != "xyes" &&
+    test "$tst_compi_inet_pton" = "yes"; then
+    AC_MSG_CHECKING([if inet_pton seems to work])
+    AC_RUN_IFELSE([
+      AC_LANG_PROGRAM([[
+        $curl_includes_stdlib
+        $curl_includes_arpa_inet
+        $curl_includes_string
+      ]],[[
+        unsigned char ipv6a[16+1];
+        unsigned char ipv4a[4+1];
+        const char *ipv6src = "fe80::214:4fff:fe0b:76c8";
+        const char *ipv4src = "192.168.100.1";
+        /* - */
+        memset(ipv4a, 1, sizeof(ipv4a));
+        if(1 != inet_pton(AF_INET, ipv4src, ipv4a))
+          exit(1); /* fail */
+        /* - */
+        if( (ipv4a[0] != 0xc0) ||
+            (ipv4a[1] != 0xa8) ||
+            (ipv4a[2] != 0x64) ||
+            (ipv4a[3] != 0x01) ||
+            (ipv4a[4] != 0x01) )
+          exit(1); /* fail */
+        /* - */
+        memset(ipv6a, 1, sizeof(ipv6a));
+        if(1 != inet_pton(AF_INET6, ipv6src, ipv6a))
+          exit(1); /* fail */
+        /* - */
+        if( (ipv6a[0]  != 0xfe) ||
+            (ipv6a[1]  != 0x80) ||
+            (ipv6a[8]  != 0x02) ||
+            (ipv6a[9]  != 0x14) ||
+            (ipv6a[10] != 0x4f) ||
+            (ipv6a[11] != 0xff) ||
+            (ipv6a[12] != 0xfe) ||
+            (ipv6a[13] != 0x0b) ||
+            (ipv6a[14] != 0x76) ||
+            (ipv6a[15] != 0xc8) ||
+            (ipv6a[16] != 0x01) )
+          exit(1); /* fail */
+        /* - */
+        if( (ipv6a[2]  != 0x0) ||
+            (ipv6a[3]  != 0x0) ||
+            (ipv6a[4]  != 0x0) ||
+            (ipv6a[5]  != 0x0) ||
+            (ipv6a[6]  != 0x0) ||
+            (ipv6a[7]  != 0x0) )
+          exit(1); /* fail */
+        /* - */
+        exit(0);
+      ]])
+    ],[
+      AC_MSG_RESULT([yes])
+      tst_works_inet_pton="yes"
+    ],[
+      AC_MSG_RESULT([no])
+      tst_works_inet_pton="no"
+    ])
+  fi
+  #
+  if test "$tst_compi_inet_pton" = "yes" &&
+    test "$tst_works_inet_pton" != "no"; then
+    AC_MSG_CHECKING([if inet_pton usage allowed])
+    if test "x$curl_disallow_inet_pton" != "xyes"; then
+      AC_MSG_RESULT([yes])
+      tst_allow_inet_pton="yes"
+    else
+      AC_MSG_RESULT([no])
+      tst_allow_inet_pton="no"
+    fi
+  fi
+  #
+  AC_MSG_CHECKING([if inet_pton might be used])
+  if test "$tst_links_inet_pton" = "yes" &&
+     test "$tst_proto_inet_pton" = "yes" &&
+     test "$tst_compi_inet_pton" = "yes" &&
+     test "$tst_allow_inet_pton" = "yes" &&
+     test "$tst_works_inet_pton" != "no"; then
+    AC_MSG_RESULT([yes])
+    AC_DEFINE_UNQUOTED(HAVE_INET_PTON, 1,
+      [Define to 1 if you have a IPv6 capable working inet_pton function.])
+    curl_cv_func_inet_pton="yes"
+  else
+    AC_MSG_RESULT([no])
+    curl_cv_func_inet_pton="no"
+  fi
+])
+
+
+dnl CURL_CHECK_FUNC_IOCTL
+dnl -------------------------------------------------
+dnl Verify if ioctl is available, prototyped, and
+dnl can be compiled. If all of these are true, and
+dnl usage has not been previously disallowed with
+dnl shell variable curl_disallow_ioctl, then
+dnl HAVE_IOCTL will be defined.
+
+AC_DEFUN([CURL_CHECK_FUNC_IOCTL], [
+  AC_REQUIRE([CURL_INCLUDES_STROPTS])dnl
+  #
+  tst_links_ioctl="unknown"
+  tst_proto_ioctl="unknown"
+  tst_compi_ioctl="unknown"
+  tst_allow_ioctl="unknown"
+  #
+  AC_MSG_CHECKING([if ioctl can be linked])
+  AC_LINK_IFELSE([
+    AC_LANG_FUNC_LINK_TRY([ioctl])
+  ],[
+    AC_MSG_RESULT([yes])
+    tst_links_ioctl="yes"
+  ],[
+    AC_MSG_RESULT([no])
+    tst_links_ioctl="no"
+  ])
+  #
+  if test "$tst_links_ioctl" = "yes"; then
+    AC_MSG_CHECKING([if ioctl is prototyped])
+    AC_EGREP_CPP([ioctl],[
+      $curl_includes_stropts
+    ],[
+      AC_MSG_RESULT([yes])
+      tst_proto_ioctl="yes"
+    ],[
+      AC_MSG_RESULT([no])
+      tst_proto_ioctl="no"
+    ])
+  fi
+  #
+  if test "$tst_proto_ioctl" = "yes"; then
+    AC_MSG_CHECKING([if ioctl is compilable])
+    AC_COMPILE_IFELSE([
+      AC_LANG_PROGRAM([[
+        $curl_includes_stropts
+      ]],[[
+        if(0 != ioctl(0, 0, 0))
+          return 1;
+      ]])
+    ],[
+      AC_MSG_RESULT([yes])
+      tst_compi_ioctl="yes"
+    ],[
+      AC_MSG_RESULT([no])
+      tst_compi_ioctl="no"
+    ])
+  fi
+  #
+  if test "$tst_compi_ioctl" = "yes"; then
+    AC_MSG_CHECKING([if ioctl usage allowed])
+    if test "x$curl_disallow_ioctl" != "xyes"; then
+      AC_MSG_RESULT([yes])
+      tst_allow_ioctl="yes"
+    else
+      AC_MSG_RESULT([no])
+      tst_allow_ioctl="no"
+    fi
+  fi
+  #
+  AC_MSG_CHECKING([if ioctl might be used])
+  if test "$tst_links_ioctl" = "yes" &&
+     test "$tst_proto_ioctl" = "yes" &&
+     test "$tst_compi_ioctl" = "yes" &&
+     test "$tst_allow_ioctl" = "yes"; then
+    AC_MSG_RESULT([yes])
+    AC_DEFINE_UNQUOTED(HAVE_IOCTL, 1,
+      [Define to 1 if you have the ioctl function.])
+    curl_cv_func_ioctl="yes"
+    CURL_CHECK_FUNC_IOCTL_FIONBIO
+    CURL_CHECK_FUNC_IOCTL_SIOCGIFADDR
+  else
+    AC_MSG_RESULT([no])
+    curl_cv_func_ioctl="no"
+  fi
+])
+
+
+dnl CURL_CHECK_FUNC_IOCTL_FIONBIO
+dnl -------------------------------------------------
+dnl Verify if ioctl with the FIONBIO command is
+dnl available, can be compiled, and seems to work. If
+dnl all of these are true, then HAVE_IOCTL_FIONBIO
+dnl will be defined.
+
+AC_DEFUN([CURL_CHECK_FUNC_IOCTL_FIONBIO], [
+  #
+  tst_compi_ioctl_fionbio="unknown"
+  tst_allow_ioctl_fionbio="unknown"
+  #
+  if test "$curl_cv_func_ioctl" = "yes"; then
+    AC_MSG_CHECKING([if ioctl FIONBIO is compilable])
+    AC_COMPILE_IFELSE([
+      AC_LANG_PROGRAM([[
+        $curl_includes_stropts
+      ]],[[
+        int flags = 0;
+        if(0 != ioctl(0, FIONBIO, &flags))
+          return 1;
+      ]])
+    ],[
+      AC_MSG_RESULT([yes])
+      tst_compi_ioctl_fionbio="yes"
+    ],[
+      AC_MSG_RESULT([no])
+      tst_compi_ioctl_fionbio="no"
+    ])
+  fi
+  #
+  if test "$tst_compi_ioctl_fionbio" = "yes"; then
+    AC_MSG_CHECKING([if ioctl FIONBIO usage allowed])
+    if test "x$curl_disallow_ioctl_fionbio" != "xyes"; then
+      AC_MSG_RESULT([yes])
+      tst_allow_ioctl_fionbio="yes"
+    else
+      AC_MSG_RESULT([no])
+      tst_allow_ioctl_fionbio="no"
+    fi
+  fi
+  #
+  AC_MSG_CHECKING([if ioctl FIONBIO might be used])
+  if test "$tst_compi_ioctl_fionbio" = "yes" &&
+     test "$tst_allow_ioctl_fionbio" = "yes"; then
+    AC_MSG_RESULT([yes])
+    AC_DEFINE_UNQUOTED(HAVE_IOCTL_FIONBIO, 1,
+      [Define to 1 if you have a working ioctl FIONBIO function.])
+    curl_cv_func_ioctl_fionbio="yes"
+  else
+    AC_MSG_RESULT([no])
+    curl_cv_func_ioctl_fionbio="no"
+  fi
+])
+
+
+dnl CURL_CHECK_FUNC_IOCTL_SIOCGIFADDR
+dnl -------------------------------------------------
+dnl Verify if ioctl with the SIOCGIFADDR command is available,
+dnl struct ifreq is defined, they can be compiled, and seem to
+dnl work. If all of these are true, then HAVE_IOCTL_SIOCGIFADDR
+dnl will be defined.
+
+AC_DEFUN([CURL_CHECK_FUNC_IOCTL_SIOCGIFADDR], [
+  #
+  tst_compi_ioctl_siocgifaddr="unknown"
+  tst_allow_ioctl_siocgifaddr="unknown"
+  #
+  if test "$curl_cv_func_ioctl" = "yes"; then
+    AC_MSG_CHECKING([if ioctl SIOCGIFADDR is compilable])
+    AC_COMPILE_IFELSE([
+      AC_LANG_PROGRAM([[
+        $curl_includes_stropts
+        #include <net/if.h>
+      ]],[[
+        struct ifreq ifr;
+        if(0 != ioctl(0, SIOCGIFADDR, &ifr))
+          return 1;
+      ]])
+    ],[
+      AC_MSG_RESULT([yes])
+      tst_compi_ioctl_siocgifaddr="yes"
+    ],[
+      AC_MSG_RESULT([no])
+      tst_compi_ioctl_siocgifaddr="no"
+    ])
+  fi
+  #
+  if test "$tst_compi_ioctl_siocgifaddr" = "yes"; then
+    AC_MSG_CHECKING([if ioctl SIOCGIFADDR usage allowed])
+    if test "x$curl_disallow_ioctl_siocgifaddr" != "xyes"; then
+      AC_MSG_RESULT([yes])
+      tst_allow_ioctl_siocgifaddr="yes"
+    else
+      AC_MSG_RESULT([no])
+      tst_allow_ioctl_siocgifaddr="no"
+    fi
+  fi
+  #
+  AC_MSG_CHECKING([if ioctl SIOCGIFADDR might be used])
+  if test "$tst_compi_ioctl_siocgifaddr" = "yes" &&
+     test "$tst_allow_ioctl_siocgifaddr" = "yes"; then
+    AC_MSG_RESULT([yes])
+    AC_DEFINE_UNQUOTED(HAVE_IOCTL_SIOCGIFADDR, 1,
+      [Define to 1 if you have a working ioctl SIOCGIFADDR function.])
+    curl_cv_func_ioctl_siocgifaddr="yes"
+  else
+    AC_MSG_RESULT([no])
+    curl_cv_func_ioctl_siocgifaddr="no"
+  fi
+])
+
+
+dnl CURL_CHECK_FUNC_IOCTLSOCKET
+dnl -------------------------------------------------
+dnl Verify if ioctlsocket is available, prototyped, and
+dnl can be compiled. If all of these are true, and
+dnl usage has not been previously disallowed with
+dnl shell variable curl_disallow_ioctlsocket, then
+dnl HAVE_IOCTLSOCKET will be defined.
+
+AC_DEFUN([CURL_CHECK_FUNC_IOCTLSOCKET], [
+  AC_REQUIRE([CURL_INCLUDES_WINSOCK2])dnl
+  #
+  tst_links_ioctlsocket="unknown"
+  tst_proto_ioctlsocket="unknown"
+  tst_compi_ioctlsocket="unknown"
+  tst_allow_ioctlsocket="unknown"
+  #
+  AC_MSG_CHECKING([if ioctlsocket can be linked])
+  AC_LINK_IFELSE([
+    AC_LANG_PROGRAM([[
+      $curl_includes_winsock2
+    ]],[[
+      if(0 != ioctlsocket(0, 0, 0))
+        return 1;
+    ]])
+  ],[
+    AC_MSG_RESULT([yes])
+    tst_links_ioctlsocket="yes"
+  ],[
+    AC_MSG_RESULT([no])
+    tst_links_ioctlsocket="no"
+  ])
+  #
+  if test "$tst_links_ioctlsocket" = "yes"; then
+    AC_MSG_CHECKING([if ioctlsocket is prototyped])
+    AC_EGREP_CPP([ioctlsocket],[
+      $curl_includes_winsock2
+    ],[
+      AC_MSG_RESULT([yes])
+      tst_proto_ioctlsocket="yes"
+    ],[
+      AC_MSG_RESULT([no])
+      tst_proto_ioctlsocket="no"
+    ])
+  fi
+  #
+  if test "$tst_proto_ioctlsocket" = "yes"; then
+    AC_MSG_CHECKING([if ioctlsocket is compilable])
+    AC_COMPILE_IFELSE([
+      AC_LANG_PROGRAM([[
+        $curl_includes_winsock2
+      ]],[[
+        if(0 != ioctlsocket(0, 0, 0))
+          return 1;
+      ]])
+    ],[
+      AC_MSG_RESULT([yes])
+      tst_compi_ioctlsocket="yes"
+    ],[
+      AC_MSG_RESULT([no])
+      tst_compi_ioctlsocket="no"
+    ])
+  fi
+  #
+  if test "$tst_compi_ioctlsocket" = "yes"; then
+    AC_MSG_CHECKING([if ioctlsocket usage allowed])
+    if test "x$curl_disallow_ioctlsocket" != "xyes"; then
+      AC_MSG_RESULT([yes])
+      tst_allow_ioctlsocket="yes"
+    else
+      AC_MSG_RESULT([no])
+      tst_allow_ioctlsocket="no"
+    fi
+  fi
+  #
+  AC_MSG_CHECKING([if ioctlsocket might be used])
+  if test "$tst_links_ioctlsocket" = "yes" &&
+     test "$tst_proto_ioctlsocket" = "yes" &&
+     test "$tst_compi_ioctlsocket" = "yes" &&
+     test "$tst_allow_ioctlsocket" = "yes"; then
+    AC_MSG_RESULT([yes])
+    AC_DEFINE_UNQUOTED(HAVE_IOCTLSOCKET, 1,
+      [Define to 1 if you have the ioctlsocket function.])
+    curl_cv_func_ioctlsocket="yes"
+    CURL_CHECK_FUNC_IOCTLSOCKET_FIONBIO
+  else
+    AC_MSG_RESULT([no])
+    curl_cv_func_ioctlsocket="no"
+  fi
+])
+
+
+dnl CURL_CHECK_FUNC_IOCTLSOCKET_FIONBIO
+dnl -------------------------------------------------
+dnl Verify if ioctlsocket with the FIONBIO command is
+dnl available, can be compiled, and seems to work. If
+dnl all of these are true, then HAVE_IOCTLSOCKET_FIONBIO
+dnl will be defined.
+
+AC_DEFUN([CURL_CHECK_FUNC_IOCTLSOCKET_FIONBIO], [
+  #
+  tst_compi_ioctlsocket_fionbio="unknown"
+  tst_allow_ioctlsocket_fionbio="unknown"
+  #
+  if test "$curl_cv_func_ioctlsocket" = "yes"; then
+    AC_MSG_CHECKING([if ioctlsocket FIONBIO is compilable])
+    AC_COMPILE_IFELSE([
+      AC_LANG_PROGRAM([[
+        $curl_includes_winsock2
+      ]],[[
+        int flags = 0;
+        if(0 != ioctlsocket(0, FIONBIO, &flags))
+          return 1;
+      ]])
+    ],[
+      AC_MSG_RESULT([yes])
+      tst_compi_ioctlsocket_fionbio="yes"
+    ],[
+      AC_MSG_RESULT([no])
+      tst_compi_ioctlsocket_fionbio="no"
+    ])
+  fi
+  #
+  if test "$tst_compi_ioctlsocket_fionbio" = "yes"; then
+    AC_MSG_CHECKING([if ioctlsocket FIONBIO usage allowed])
+    if test "x$curl_disallow_ioctlsocket_fionbio" != "xyes"; then
+      AC_MSG_RESULT([yes])
+      tst_allow_ioctlsocket_fionbio="yes"
+    else
+      AC_MSG_RESULT([no])
+      tst_allow_ioctlsocket_fionbio="no"
+    fi
+  fi
+  #
+  AC_MSG_CHECKING([if ioctlsocket FIONBIO might be used])
+  if test "$tst_compi_ioctlsocket_fionbio" = "yes" &&
+     test "$tst_allow_ioctlsocket_fionbio" = "yes"; then
+    AC_MSG_RESULT([yes])
+    AC_DEFINE_UNQUOTED(HAVE_IOCTLSOCKET_FIONBIO, 1,
+      [Define to 1 if you have a working ioctlsocket FIONBIO function.])
+    curl_cv_func_ioctlsocket_fionbio="yes"
+  else
+    AC_MSG_RESULT([no])
+    curl_cv_func_ioctlsocket_fionbio="no"
+  fi
+])
+
+
+dnl CURL_CHECK_FUNC_IOCTLSOCKET_CAMEL
+dnl -------------------------------------------------
+dnl Verify if IoctlSocket is available, prototyped, and
+dnl can be compiled. If all of these are true, and
+dnl usage has not been previously disallowed with
+dnl shell variable curl_disallow_ioctlsocket_camel,
+dnl then HAVE_IOCTLSOCKET_CAMEL will be defined.
+
+AC_DEFUN([CURL_CHECK_FUNC_IOCTLSOCKET_CAMEL], [
+  AC_REQUIRE([CURL_INCLUDES_STROPTS])dnl
+  #
+  tst_links_ioctlsocket_camel="unknown"
+  tst_proto_ioctlsocket_camel="unknown"
+  tst_compi_ioctlsocket_camel="unknown"
+  tst_allow_ioctlsocket_camel="unknown"
+  #
+  AC_MSG_CHECKING([if IoctlSocket can be linked])
+  AC_LINK_IFELSE([
+    AC_LANG_FUNC_LINK_TRY([IoctlSocket])
+  ],[
+    AC_MSG_RESULT([yes])
+    tst_links_ioctlsocket_camel="yes"
+  ],[
+    AC_MSG_RESULT([no])
+    tst_links_ioctlsocket_camel="no"
+  ])
+  #
+  if test "$tst_links_ioctlsocket_camel" = "yes"; then
+    AC_MSG_CHECKING([if IoctlSocket is prototyped])
+    AC_EGREP_CPP([IoctlSocket],[
+      $curl_includes_stropts
+    ],[
+      AC_MSG_RESULT([yes])
+      tst_proto_ioctlsocket_camel="yes"
+    ],[
+      AC_MSG_RESULT([no])
+      tst_proto_ioctlsocket_camel="no"
+    ])
+  fi
+  #
+  if test "$tst_proto_ioctlsocket_camel" = "yes"; then
+    AC_MSG_CHECKING([if IoctlSocket is compilable])
+    AC_COMPILE_IFELSE([
+      AC_LANG_PROGRAM([[
+        $curl_includes_stropts
+      ]],[[
+        if(0 != IoctlSocket(0, 0, 0))
+          return 1;
+      ]])
+    ],[
+      AC_MSG_RESULT([yes])
+      tst_compi_ioctlsocket_camel="yes"
+    ],[
+      AC_MSG_RESULT([no])
+      tst_compi_ioctlsocket_camel="no"
+    ])
+  fi
+  #
+  if test "$tst_compi_ioctlsocket_camel" = "yes"; then
+    AC_MSG_CHECKING([if IoctlSocket usage allowed])
+    if test "x$curl_disallow_ioctlsocket_camel" != "xyes"; then
+      AC_MSG_RESULT([yes])
+      tst_allow_ioctlsocket_camel="yes"
+    else
+      AC_MSG_RESULT([no])
+      tst_allow_ioctlsocket_camel="no"
+    fi
+  fi
+  #
+  AC_MSG_CHECKING([if IoctlSocket might be used])
+  if test "$tst_links_ioctlsocket_camel" = "yes" &&
+     test "$tst_proto_ioctlsocket_camel" = "yes" &&
+     test "$tst_compi_ioctlsocket_camel" = "yes" &&
+     test "$tst_allow_ioctlsocket_camel" = "yes"; then
+    AC_MSG_RESULT([yes])
+    AC_DEFINE_UNQUOTED(HAVE_IOCTLSOCKET_CAMEL, 1,
+      [Define to 1 if you have the IoctlSocket camel case function.])
+    curl_cv_func_ioctlsocket_camel="yes"
+    CURL_CHECK_FUNC_IOCTLSOCKET_CAMEL_FIONBIO
+  else
+    AC_MSG_RESULT([no])
+    curl_cv_func_ioctlsocket_camel="no"
+  fi
+])
+
+
+dnl CURL_CHECK_FUNC_IOCTLSOCKET_CAMEL_FIONBIO
+dnl -------------------------------------------------
+dnl Verify if IoctlSocket with FIONBIO command is available,
+dnl can be compiled, and seems to work. If all of these are
+dnl true, then HAVE_IOCTLSOCKET_CAMEL_FIONBIO will be defined.
+
+AC_DEFUN([CURL_CHECK_FUNC_IOCTLSOCKET_CAMEL_FIONBIO], [
+  #
+  tst_compi_ioctlsocket_camel_fionbio="unknown"
+  tst_allow_ioctlsocket_camel_fionbio="unknown"
+  #
+  if test "$curl_cv_func_ioctlsocket_camel" = "yes"; then
+    AC_MSG_CHECKING([if IoctlSocket FIONBIO is compilable])
+    AC_COMPILE_IFELSE([
+      AC_LANG_PROGRAM([[
+        $curl_includes_stropts
+      ]],[[
+        long flags = 0;
+        if(0 != ioctlsocket(0, FIONBIO, &flags))
+          return 1;
+      ]])
+    ],[
+      AC_MSG_RESULT([yes])
+      tst_compi_ioctlsocket_camel_fionbio="yes"
+    ],[
+      AC_MSG_RESULT([no])
+      tst_compi_ioctlsocket_camel_fionbio="no"
+    ])
+  fi
+  #
+  if test "$tst_compi_ioctlsocket_camel_fionbio" = "yes"; then
+    AC_MSG_CHECKING([if IoctlSocket FIONBIO usage allowed])
+    if test "x$curl_disallow_ioctlsocket_camel_fionbio" != "xyes"; then
+      AC_MSG_RESULT([yes])
+      tst_allow_ioctlsocket_camel_fionbio="yes"
+    else
+      AC_MSG_RESULT([no])
+      tst_allow_ioctlsocket_camel_fionbio="no"
+    fi
+  fi
+  #
+  AC_MSG_CHECKING([if IoctlSocket FIONBIO might be used])
+  if test "$tst_compi_ioctlsocket_camel_fionbio" = "yes" &&
+     test "$tst_allow_ioctlsocket_camel_fionbio" = "yes"; then
+    AC_MSG_RESULT([yes])
+    AC_DEFINE_UNQUOTED(HAVE_IOCTLSOCKET_CAMEL_FIONBIO, 1,
+      [Define to 1 if you have a working IoctlSocket camel case FIONBIO function.])
+    curl_cv_func_ioctlsocket_camel_fionbio="yes"
+  else
+    AC_MSG_RESULT([no])
+    curl_cv_func_ioctlsocket_camel_fionbio="no"
+  fi
+])
+
+
+dnl CURL_CHECK_FUNC_LISTXATTR
+dnl -------------------------------------------------
+dnl Verify if listxattr is available, prototyped, and
+dnl can be compiled. If all of these are true, and
+dnl usage has not been previously disallowed with
+dnl shell variable curl_disallow_listxattr, then
+dnl HAVE_LISTXATTR will be defined.
+
+AC_DEFUN([CURL_CHECK_FUNC_LISTXATTR], [
+  AC_REQUIRE([CURL_INCLUDES_SYS_XATTR])dnl
+  #
+  tst_links_listxattr="unknown"
+  tst_proto_listxattr="unknown"
+  tst_compi_listxattr="unknown"
+  tst_allow_listxattr="unknown"
+  tst_nargs_listxattr="unknown"
+  #
+  AC_MSG_CHECKING([if listxattr can be linked])
+  AC_LINK_IFELSE([
+    AC_LANG_FUNC_LINK_TRY([listxattr])
+  ],[
+    AC_MSG_RESULT([yes])
+    tst_links_listxattr="yes"
+  ],[
+    AC_MSG_RESULT([no])
+    tst_links_listxattr="no"
+  ])
+  #
+  if test "$tst_links_listxattr" = "yes"; then
+    AC_MSG_CHECKING([if listxattr is prototyped])
+    AC_EGREP_CPP([listxattr],[
+      $curl_includes_sys_xattr
+    ],[
+      AC_MSG_RESULT([yes])
+      tst_proto_listxattr="yes"
+    ],[
+      AC_MSG_RESULT([no])
+      tst_proto_listxattr="no"
+    ])
+  fi
+  #
+  if test "$tst_proto_listxattr" = "yes"; then
+    if test "$tst_nargs_listxattr" = "unknown"; then
+      AC_MSG_CHECKING([if listxattr takes 3 args.])
+      AC_COMPILE_IFELSE([
+        AC_LANG_PROGRAM([[
+          $curl_includes_sys_xattr
+        ]],[[
+          if(0 != listxattr(0, 0, 0))
+            return 1;
+        ]])
+      ],[
+        AC_MSG_RESULT([yes])
+        tst_compi_listxattr="yes"
+        tst_nargs_listxattr="3"
+      ],[
+        AC_MSG_RESULT([no])
+        tst_compi_listxattr="no"
+      ])
+    fi
+    if test "$tst_nargs_listxattr" = "unknown"; then
+      AC_MSG_CHECKING([if listxattr takes 4 args.])
+      AC_COMPILE_IFELSE([
+        AC_LANG_PROGRAM([[
+          $curl_includes_sys_xattr
+        ]],[[
+          if(0 != listxattr(0, 0, 0, 0))
+            return 1;
+        ]])
+      ],[
+        AC_MSG_RESULT([yes])
+        tst_compi_listxattr="yes"
+        tst_nargs_listxattr="4"
+      ],[
+        AC_MSG_RESULT([no])
+        tst_compi_listxattr="no"
+      ])
+    fi
+    AC_MSG_CHECKING([if listxattr is compilable])
+    if test "$tst_compi_listxattr" = "yes"; then
+      AC_MSG_RESULT([yes])
+    else
+      AC_MSG_RESULT([no])
+    fi
+  fi
+  #
+  if test "$tst_compi_listxattr" = "yes"; then
+    AC_MSG_CHECKING([if listxattr usage allowed])
+    if test "x$curl_disallow_listxattr" != "xyes"; then
+      AC_MSG_RESULT([yes])
+      tst_allow_listxattr="yes"
+    else
+      AC_MSG_RESULT([no])
+      tst_allow_listxattr="no"
+    fi
+  fi
+  #
+  AC_MSG_CHECKING([if listxattr might be used])
+  if test "$tst_links_listxattr" = "yes" &&
+     test "$tst_proto_listxattr" = "yes" &&
+     test "$tst_compi_listxattr" = "yes" &&
+     test "$tst_allow_listxattr" = "yes"; then
+    AC_MSG_RESULT([yes])
+    AC_DEFINE_UNQUOTED(HAVE_LISTXATTR, 1,
+      [Define to 1 if you have the listxattr function.])
+    dnl AC_DEFINE_UNQUOTED(LISTXATTR_ARGS, $tst_nargs_listxattr,
+    dnl   [Specifies the number of arguments to listxattr])
+    #
+    if test "$tst_nargs_listxattr" -eq "3"; then
+      AC_DEFINE(HAVE_LISTXATTR_3, 1, [listxattr() takes 3 args])
+    elif test "$tst_nargs_listxattr" -eq "4"; then
+      AC_DEFINE(HAVE_LISTXATTR_4, 1, [listxattr() takes 4 args])
+    fi
+    #
+    curl_cv_func_listxattr="yes"
+  else
+    AC_MSG_RESULT([no])
+    curl_cv_func_listxattr="no"
+  fi
+])
+
+
+dnl CURL_CHECK_FUNC_LOCALTIME_R
+dnl -------------------------------------------------
+dnl Verify if localtime_r is available, prototyped, can
+dnl be compiled and seems to work. If all of these are
+dnl true, and usage has not been previously disallowed
+dnl with shell variable curl_disallow_localtime_r, then
+dnl HAVE_LOCALTIME_R will be defined.
+
+AC_DEFUN([CURL_CHECK_FUNC_LOCALTIME_R], [
+  AC_REQUIRE([CURL_INCLUDES_STDLIB])dnl
+  AC_REQUIRE([CURL_INCLUDES_TIME])dnl
+  #
+  tst_links_localtime_r="unknown"
+  tst_proto_localtime_r="unknown"
+  tst_compi_localtime_r="unknown"
+  tst_works_localtime_r="unknown"
+  tst_allow_localtime_r="unknown"
+  #
+  AC_MSG_CHECKING([if localtime_r can be linked])
+  AC_LINK_IFELSE([
+    AC_LANG_FUNC_LINK_TRY([localtime_r])
+  ],[
+    AC_MSG_RESULT([yes])
+    tst_links_localtime_r="yes"
+  ],[
+    AC_MSG_RESULT([no])
+    tst_links_localtime_r="no"
+  ])
+  #
+  if test "$tst_links_localtime_r" = "yes"; then
+    AC_MSG_CHECKING([if localtime_r is prototyped])
+    AC_EGREP_CPP([localtime_r],[
+      $curl_includes_time
+    ],[
+      AC_MSG_RESULT([yes])
+      tst_proto_localtime_r="yes"
+    ],[
+      AC_MSG_RESULT([no])
+      tst_proto_localtime_r="no"
+    ])
+  fi
+  #
+  if test "$tst_proto_localtime_r" = "yes"; then
+    AC_MSG_CHECKING([if localtime_r is compilable])
+    AC_COMPILE_IFELSE([
+      AC_LANG_PROGRAM([[
+        $curl_includes_time
+      ]],[[
+        if(0 != localtime_r(0, 0))
+          return 1;
+      ]])
+    ],[
+      AC_MSG_RESULT([yes])
+      tst_compi_localtime_r="yes"
+    ],[
+      AC_MSG_RESULT([no])
+      tst_compi_localtime_r="no"
+    ])
+  fi
+  #
+  dnl only do runtime verification when not cross-compiling
+  if test "x$cross_compiling" != "xyes" &&
+    test "$tst_compi_localtime_r" = "yes"; then
+    AC_MSG_CHECKING([if localtime_r seems to work])
+    AC_RUN_IFELSE([
+      AC_LANG_PROGRAM([[
+        $curl_includes_stdlib
+        $curl_includes_time
+      ]],[[
+        time_t clock = 1170352587;
+        struct tm *tmp = 0;
+        struct tm result;
+        tmp = localtime_r(&clock, &result);
+        if(tmp)
+          exit(0);
+        else
+          exit(1);
+      ]])
+    ],[
+      AC_MSG_RESULT([yes])
+      tst_works_localtime_r="yes"
+    ],[
+      AC_MSG_RESULT([no])
+      tst_works_localtime_r="no"
+    ])
+  fi
+  #
+  if test "$tst_compi_localtime_r" = "yes" &&
+    test "$tst_works_localtime_r" != "no"; then
+    AC_MSG_CHECKING([if localtime_r usage allowed])
+    if test "x$curl_disallow_localtime_r" != "xyes"; then
+      AC_MSG_RESULT([yes])
+      tst_allow_localtime_r="yes"
+    else
+      AC_MSG_RESULT([no])
+      tst_allow_localtime_r="no"
+    fi
+  fi
+  #
+  AC_MSG_CHECKING([if localtime_r might be used])
+  if test "$tst_links_localtime_r" = "yes" &&
+     test "$tst_proto_localtime_r" = "yes" &&
+     test "$tst_compi_localtime_r" = "yes" &&
+     test "$tst_allow_localtime_r" = "yes" &&
+     test "$tst_works_localtime_r" != "no"; then
+    AC_MSG_RESULT([yes])
+    AC_DEFINE_UNQUOTED(HAVE_LOCALTIME_R, 1,
+      [Define to 1 if you have a working localtime_r function.])
+    curl_cv_func_localtime_r="yes"
+  else
+    AC_MSG_RESULT([no])
+    curl_cv_func_localtime_r="no"
+  fi
+])
+
+
+dnl CURL_CHECK_FUNC_MEMRCHR
+dnl -------------------------------------------------
+dnl Verify if memrchr is available, prototyped, and
+dnl can be compiled. If all of these are true, and
+dnl usage has not been previously disallowed with
+dnl shell variable curl_disallow_memrchr, then
+dnl HAVE_MEMRCHR will be defined.
+
+AC_DEFUN([CURL_CHECK_FUNC_MEMRCHR], [
+  AC_REQUIRE([CURL_INCLUDES_STRING])dnl
+  #
+  tst_links_memrchr="unknown"
+  tst_macro_memrchr="unknown"
+  tst_proto_memrchr="unknown"
+  tst_compi_memrchr="unknown"
+  tst_allow_memrchr="unknown"
+  #
+  AC_MSG_CHECKING([if memrchr can be linked])
+  AC_LINK_IFELSE([
+    AC_LANG_FUNC_LINK_TRY([memrchr])
+  ],[
+    AC_MSG_RESULT([yes])
+    tst_links_memrchr="yes"
+  ],[
+    AC_MSG_RESULT([no])
+    tst_links_memrchr="no"
+  ])
+  #
+  if test "$tst_links_memrchr" = "no"; then
+    AC_MSG_CHECKING([if memrchr seems a macro])
+    AC_LINK_IFELSE([
+      AC_LANG_PROGRAM([[
+        $curl_includes_string
+      ]],[[
+        if(0 != memrchr(0, 0, 0))
+          return 1;
+      ]])
+    ],[
+      AC_MSG_RESULT([yes])
+      tst_macro_memrchr="yes"
+    ],[
+      AC_MSG_RESULT([no])
+      tst_macro_memrchr="no"
+    ])
+  fi
+  #
+  if test "$tst_links_memrchr" = "yes"; then
+    AC_MSG_CHECKING([if memrchr is prototyped])
+    AC_EGREP_CPP([memrchr],[
+      $curl_includes_string
+    ],[
+      AC_MSG_RESULT([yes])
+      tst_proto_memrchr="yes"
+    ],[
+      AC_MSG_RESULT([no])
+      tst_proto_memrchr="no"
+    ])
+  fi
+  #
+  if test "$tst_proto_memrchr" = "yes" ||
+     test "$tst_macro_memrchr" = "yes"; then
+    AC_MSG_CHECKING([if memrchr is compilable])
+    AC_COMPILE_IFELSE([
+      AC_LANG_PROGRAM([[
+        $curl_includes_string
+      ]],[[
+        if(0 != memrchr(0, 0, 0))
+          return 1;
+      ]])
+    ],[
+      AC_MSG_RESULT([yes])
+      tst_compi_memrchr="yes"
+    ],[
+      AC_MSG_RESULT([no])
+      tst_compi_memrchr="no"
+    ])
+  fi
+  #
+  if test "$tst_compi_memrchr" = "yes"; then
+    AC_MSG_CHECKING([if memrchr usage allowed])
+    if test "x$curl_disallow_memrchr" != "xyes"; then
+      AC_MSG_RESULT([yes])
+      tst_allow_memrchr="yes"
+    else
+      AC_MSG_RESULT([no])
+      tst_allow_memrchr="no"
+    fi
+  fi
+  #
+  AC_MSG_CHECKING([if memrchr might be used])
+  if (test "$tst_proto_memrchr" = "yes" ||
+      test "$tst_macro_memrchr" = "yes") &&
+     test "$tst_compi_memrchr" = "yes" &&
+     test "$tst_allow_memrchr" = "yes"; then
+    AC_MSG_RESULT([yes])
+    AC_DEFINE_UNQUOTED(HAVE_MEMRCHR, 1,
+      [Define to 1 if you have the memrchr function or macro.])
+    curl_cv_func_memrchr="yes"
+  else
+    AC_MSG_RESULT([no])
+    curl_cv_func_memrchr="no"
+  fi
+])
+
+
+dnl CURL_CHECK_FUNC_POLL
+dnl -------------------------------------------------
+dnl Verify if poll is available, prototyped, can
+dnl be compiled and seems to work. If all of these are
+dnl true, and usage has not been previously disallowed
+dnl with shell variable curl_disallow_poll, then
+dnl HAVE_POLL will be defined.
+
+AC_DEFUN([CURL_CHECK_FUNC_POLL], [
+  AC_REQUIRE([CURL_INCLUDES_STDLIB])dnl
+  AC_REQUIRE([CURL_INCLUDES_POLL])dnl
+  #
+  tst_links_poll="unknown"
+  tst_proto_poll="unknown"
+  tst_compi_poll="unknown"
+  tst_works_poll="unknown"
+  tst_allow_poll="unknown"
+  #
+  case $host_os in
+    darwin*|interix*)
+      dnl poll() does not work on these platforms
+      dnl Interix: "does provide poll(), but the implementing developer must
+      dnl have been in a bad mood, because poll() only works on the /proc
+      dnl filesystem here"
+      dnl macOS: poll() first didn't exist, then was broken until fixed in 10.9
+      dnl only to break again in 10.12.
+      curl_disallow_poll="yes"
+      tst_compi_poll="no"
+      ;;
+  esac
+  #
+  AC_MSG_CHECKING([if poll can be linked])
+  AC_LINK_IFELSE([
+    AC_LANG_PROGRAM([[
+      $curl_includes_poll
+    ]],[[
+      if(0 != poll(0, 0, 0))
+        return 1;
+    ]])
+  ],[
+    AC_MSG_RESULT([yes])
+    tst_links_poll="yes"
+  ],[
+    AC_MSG_RESULT([no])
+    tst_links_poll="no"
+  ])
+  #
+  if test "$tst_links_poll" = "yes"; then
+    AC_MSG_CHECKING([if poll is prototyped])
+    AC_EGREP_CPP([poll],[
+      $curl_includes_poll
+    ],[
+      AC_MSG_RESULT([yes])
+      tst_proto_poll="yes"
+    ],[
+      AC_MSG_RESULT([no])
+      tst_proto_poll="no"
+    ])
+  fi
+  #
+  if test "$tst_proto_poll" = "yes"; then
+    AC_MSG_CHECKING([if poll is compilable])
+    AC_COMPILE_IFELSE([
+      AC_LANG_PROGRAM([[
+        $curl_includes_poll
+      ]],[[
+        if(0 != poll(0, 0, 0))
+          return 1;
+      ]])
+    ],[
+      AC_MSG_RESULT([yes])
+      tst_compi_poll="yes"
+    ],[
+      AC_MSG_RESULT([no])
+      tst_compi_poll="no"
+    ])
+  fi
+  #
+  dnl only do runtime verification when not cross-compiling
+  if test "x$cross_compiling" != "xyes" &&
+    test "$tst_compi_poll" = "yes"; then
+    AC_MSG_CHECKING([if poll seems to work])
+    AC_RUN_IFELSE([
+      AC_LANG_PROGRAM([[
+        $curl_includes_stdlib
+        $curl_includes_poll
+        $curl_includes_time
+      ]],[[
+        /* detect the original poll() breakage */
+        if(0 != poll(0, 0, 10))
+          exit(1); /* fail */
+        else {
+          /* detect the 10.12 poll() breakage */
+          struct timeval before, after;
+          int rc;
+          size_t us;
+
+          gettimeofday(&before, NULL);
+          rc = poll(NULL, 0, 500);
+          gettimeofday(&after, NULL);
+
+          us = (after.tv_sec - before.tv_sec) * 1000000 +
+            (after.tv_usec - before.tv_usec);
+
+          if(us < 400000)
+            exit(1);
+        }
+      ]])
+    ],[
+      AC_MSG_RESULT([yes])
+      tst_works_poll="yes"
+    ],[
+      AC_MSG_RESULT([no])
+      tst_works_poll="no"
+    ])
+  fi
+  #
+  if test "$tst_compi_poll" = "yes" &&
+    test "$tst_works_poll" != "no"; then
+    AC_MSG_CHECKING([if poll usage allowed])
+    if test "x$curl_disallow_poll" != "xyes"; then
+      AC_MSG_RESULT([yes])
+      tst_allow_poll="yes"
+    else
+      AC_MSG_RESULT([no])
+      tst_allow_poll="no"
+    fi
+  fi
+  #
+  AC_MSG_CHECKING([if poll might be used])
+  if test "$tst_links_poll" = "yes" &&
+     test "$tst_proto_poll" = "yes" &&
+     test "$tst_compi_poll" = "yes" &&
+     test "$tst_allow_poll" = "yes" &&
+     test "$tst_works_poll" != "no"; then
+    AC_MSG_RESULT([yes])
+    AC_DEFINE_UNQUOTED(HAVE_POLL, 1,
+      [Define to 1 if you have a working poll function.])
+    AC_DEFINE_UNQUOTED(HAVE_POLL_FINE, 1,
+      [If you have a fine poll])
+    curl_cv_func_poll="yes"
+  else
+    AC_MSG_RESULT([no])
+    curl_cv_func_poll="no"
+  fi
+])
+
+
+dnl CURL_CHECK_FUNC_REMOVEXATTR
+dnl -------------------------------------------------
+dnl Verify if removexattr is available, prototyped, and
+dnl can be compiled. If all of these are true, and
+dnl usage has not been previously disallowed with
+dnl shell variable curl_disallow_removexattr, then
+dnl HAVE_REMOVEXATTR will be defined.
+
+AC_DEFUN([CURL_CHECK_FUNC_REMOVEXATTR], [
+  AC_REQUIRE([CURL_INCLUDES_SYS_XATTR])dnl
+  #
+  tst_links_removexattr="unknown"
+  tst_proto_removexattr="unknown"
+  tst_compi_removexattr="unknown"
+  tst_allow_removexattr="unknown"
+  tst_nargs_removexattr="unknown"
+  #
+  AC_MSG_CHECKING([if removexattr can be linked])
+  AC_LINK_IFELSE([
+    AC_LANG_FUNC_LINK_TRY([removexattr])
+  ],[
+    AC_MSG_RESULT([yes])
+    tst_links_removexattr="yes"
+  ],[
+    AC_MSG_RESULT([no])
+    tst_links_removexattr="no"
+  ])
+  #
+  if test "$tst_links_removexattr" = "yes"; then
+    AC_MSG_CHECKING([if removexattr is prototyped])
+    AC_EGREP_CPP([removexattr],[
+      $curl_includes_sys_xattr
+    ],[
+      AC_MSG_RESULT([yes])
+      tst_proto_removexattr="yes"
+    ],[
+      AC_MSG_RESULT([no])
+      tst_proto_removexattr="no"
+    ])
+  fi
+  #
+  if test "$tst_proto_removexattr" = "yes"; then
+    if test "$tst_nargs_removexattr" = "unknown"; then
+      AC_MSG_CHECKING([if removexattr takes 2 args.])
+      AC_COMPILE_IFELSE([
+        AC_LANG_PROGRAM([[
+          $curl_includes_sys_xattr
+        ]],[[
+          if(0 != removexattr(0, 0))
+            return 1;
+        ]])
+      ],[
+        AC_MSG_RESULT([yes])
+        tst_compi_removexattr="yes"
+        tst_nargs_removexattr="2"
+      ],[
+        AC_MSG_RESULT([no])
+        tst_compi_removexattr="no"
+      ])
+    fi
+    if test "$tst_nargs_removexattr" = "unknown"; then
+      AC_MSG_CHECKING([if removexattr takes 3 args.])
+      AC_COMPILE_IFELSE([
+        AC_LANG_PROGRAM([[
+          $curl_includes_sys_xattr
+        ]],[[
+          if(0 != removexattr(0, 0, 0))
+            return 1;
+        ]])
+      ],[
+        AC_MSG_RESULT([yes])
+        tst_compi_removexattr="yes"
+        tst_nargs_removexattr="3"
+      ],[
+        AC_MSG_RESULT([no])
+        tst_compi_removexattr="no"
+      ])
+    fi
+    AC_MSG_CHECKING([if removexattr is compilable])
+    if test "$tst_compi_removexattr" = "yes"; then
+      AC_MSG_RESULT([yes])
+    else
+      AC_MSG_RESULT([no])
+    fi
+  fi
+  #
+  if test "$tst_compi_removexattr" = "yes"; then
+    AC_MSG_CHECKING([if removexattr usage allowed])
+    if test "x$curl_disallow_removexattr" != "xyes"; then
+      AC_MSG_RESULT([yes])
+      tst_allow_removexattr="yes"
+    else
+      AC_MSG_RESULT([no])
+      tst_allow_removexattr="no"
+    fi
+  fi
+  #
+  AC_MSG_CHECKING([if removexattr might be used])
+  if test "$tst_links_removexattr" = "yes" &&
+     test "$tst_proto_removexattr" = "yes" &&
+     test "$tst_compi_removexattr" = "yes" &&
+     test "$tst_allow_removexattr" = "yes"; then
+    AC_MSG_RESULT([yes])
+    AC_DEFINE_UNQUOTED(HAVE_REMOVEXATTR, 1,
+      [Define to 1 if you have the removexattr function.])
+    dnl AC_DEFINE_UNQUOTED(REMOVEXATTR_ARGS, $tst_nargs_removexattr,
+    dnl   [Specifies the number of arguments to removexattr])
+    #
+    if test "$tst_nargs_removexattr" -eq "2"; then
+      AC_DEFINE(HAVE_REMOVEXATTR_2, 1, [removexattr() takes 2 args])
+    elif test "$tst_nargs_removexattr" -eq "3"; then
+      AC_DEFINE(HAVE_REMOVEXATTR_3, 1, [removexattr() takes 3 args])
+    fi
+    #
+    curl_cv_func_removexattr="yes"
+  else
+    AC_MSG_RESULT([no])
+    curl_cv_func_removexattr="no"
+  fi
+])
+
+
+dnl CURL_CHECK_FUNC_SETSOCKOPT
+dnl -------------------------------------------------
+dnl Verify if setsockopt is available, prototyped, and
+dnl can be compiled. If all of these are true, and
+dnl usage has not been previously disallowed with
+dnl shell variable curl_disallow_setsockopt, then
+dnl HAVE_SETSOCKOPT will be defined.
+
+AC_DEFUN([CURL_CHECK_FUNC_SETSOCKOPT], [
+  AC_REQUIRE([CURL_INCLUDES_WINSOCK2])dnl
+  AC_REQUIRE([CURL_INCLUDES_SYS_SOCKET])dnl
+  #
+  tst_links_setsockopt="unknown"
+  tst_proto_setsockopt="unknown"
+  tst_compi_setsockopt="unknown"
+  tst_allow_setsockopt="unknown"
+  #
+  AC_MSG_CHECKING([if setsockopt can be linked])
+  AC_LINK_IFELSE([
+    AC_LANG_PROGRAM([[
+      $curl_includes_winsock2
+      $curl_includes_sys_socket
+    ]],[[
+      if(0 != setsockopt(0, 0, 0, 0, 0))
+        return 1;
+    ]])
+  ],[
+    AC_MSG_RESULT([yes])
+    tst_links_setsockopt="yes"
+  ],[
+    AC_MSG_RESULT([no])
+    tst_links_setsockopt="no"
+  ])
+  #
+  if test "$tst_links_setsockopt" = "yes"; then
+    AC_MSG_CHECKING([if setsockopt is prototyped])
+    AC_EGREP_CPP([setsockopt],[
+      $curl_includes_winsock2
+      $curl_includes_sys_socket
+    ],[
+      AC_MSG_RESULT([yes])
+      tst_proto_setsockopt="yes"
+    ],[
+      AC_MSG_RESULT([no])
+      tst_proto_setsockopt="no"
+    ])
+  fi
+  #
+  if test "$tst_proto_setsockopt" = "yes"; then
+    AC_MSG_CHECKING([if setsockopt is compilable])
+    AC_COMPILE_IFELSE([
+      AC_LANG_PROGRAM([[
+        $curl_includes_winsock2
+        $curl_includes_sys_socket
+      ]],[[
+        if(0 != setsockopt(0, 0, 0, 0, 0))
+          return 1;
+      ]])
+    ],[
+      AC_MSG_RESULT([yes])
+      tst_compi_setsockopt="yes"
+    ],[
+      AC_MSG_RESULT([no])
+      tst_compi_setsockopt="no"
+    ])
+  fi
+  #
+  if test "$tst_compi_setsockopt" = "yes"; then
+    AC_MSG_CHECKING([if setsockopt usage allowed])
+    if test "x$curl_disallow_setsockopt" != "xyes"; then
+      AC_MSG_RESULT([yes])
+      tst_allow_setsockopt="yes"
+    else
+      AC_MSG_RESULT([no])
+      tst_allow_setsockopt="no"
+    fi
+  fi
+  #
+  AC_MSG_CHECKING([if setsockopt might be used])
+  if test "$tst_links_setsockopt" = "yes" &&
+     test "$tst_proto_setsockopt" = "yes" &&
+     test "$tst_compi_setsockopt" = "yes" &&
+     test "$tst_allow_setsockopt" = "yes"; then
+    AC_MSG_RESULT([yes])
+    AC_DEFINE_UNQUOTED(HAVE_SETSOCKOPT, 1,
+      [Define to 1 if you have the setsockopt function.])
+    curl_cv_func_setsockopt="yes"
+    CURL_CHECK_FUNC_SETSOCKOPT_SO_NONBLOCK
+  else
+    AC_MSG_RESULT([no])
+    curl_cv_func_setsockopt="no"
+  fi
+])
+
+
+dnl CURL_CHECK_FUNC_SETSOCKOPT_SO_NONBLOCK
+dnl -------------------------------------------------
+dnl Verify if setsockopt with the SO_NONBLOCK command is
+dnl available, can be compiled, and seems to work. If
+dnl all of these are true, then HAVE_SETSOCKOPT_SO_NONBLOCK
+dnl will be defined.
+
+AC_DEFUN([CURL_CHECK_FUNC_SETSOCKOPT_SO_NONBLOCK], [
+  #
+  tst_compi_setsockopt_so_nonblock="unknown"
+  tst_allow_setsockopt_so_nonblock="unknown"
+  #
+  if test "$curl_cv_func_setsockopt" = "yes"; then
+    AC_MSG_CHECKING([if setsockopt SO_NONBLOCK is compilable])
+    AC_COMPILE_IFELSE([
+      AC_LANG_PROGRAM([[
+        $curl_includes_winsock2
+        $curl_includes_sys_socket
+      ]],[[
+        if(0 != setsockopt(0, SOL_SOCKET, SO_NONBLOCK, 0, 0))
+          return 1;
+      ]])
+    ],[
+      AC_MSG_RESULT([yes])
+      tst_compi_setsockopt_so_nonblock="yes"
+    ],[
+      AC_MSG_RESULT([no])
+      tst_compi_setsockopt_so_nonblock="no"
+    ])
+  fi
+  #
+  if test "$tst_compi_setsockopt_so_nonblock" = "yes"; then
+    AC_MSG_CHECKING([if setsockopt SO_NONBLOCK usage allowed])
+    if test "x$curl_disallow_setsockopt_so_nonblock" != "xyes"; then
+      AC_MSG_RESULT([yes])
+      tst_allow_setsockopt_so_nonblock="yes"
+    else
+      AC_MSG_RESULT([no])
+      tst_allow_setsockopt_so_nonblock="no"
+    fi
+  fi
+  #
+  AC_MSG_CHECKING([if setsockopt SO_NONBLOCK might be used])
+  if test "$tst_compi_setsockopt_so_nonblock" = "yes" &&
+     test "$tst_allow_setsockopt_so_nonblock" = "yes"; then
+    AC_MSG_RESULT([yes])
+    AC_DEFINE_UNQUOTED(HAVE_SETSOCKOPT_SO_NONBLOCK, 1,
+      [Define to 1 if you have a working setsockopt SO_NONBLOCK function.])
+    curl_cv_func_setsockopt_so_nonblock="yes"
+  else
+    AC_MSG_RESULT([no])
+    curl_cv_func_setsockopt_so_nonblock="no"
+  fi
+])
+
+
+dnl CURL_CHECK_FUNC_SETXATTR
+dnl -------------------------------------------------
+dnl Verify if setxattr is available, prototyped, and
+dnl can be compiled. If all of these are true, and
+dnl usage has not been previously disallowed with
+dnl shell variable curl_disallow_setxattr, then
+dnl HAVE_SETXATTR will be defined.
+
+AC_DEFUN([CURL_CHECK_FUNC_SETXATTR], [
+  AC_REQUIRE([CURL_INCLUDES_SYS_XATTR])dnl
+  #
+  tst_links_setxattr="unknown"
+  tst_proto_setxattr="unknown"
+  tst_compi_setxattr="unknown"
+  tst_allow_setxattr="unknown"
+  tst_nargs_setxattr="unknown"
+  #
+  AC_MSG_CHECKING([if setxattr can be linked])
+  AC_LINK_IFELSE([
+    AC_LANG_FUNC_LINK_TRY([setxattr])
+  ],[
+    AC_MSG_RESULT([yes])
+    tst_links_setxattr="yes"
+  ],[
+    AC_MSG_RESULT([no])
+    tst_links_setxattr="no"
+  ])
+  #
+  if test "$tst_links_setxattr" = "yes"; then
+    AC_MSG_CHECKING([if setxattr is prototyped])
+    AC_EGREP_CPP([setxattr],[
+      $curl_includes_sys_xattr
+    ],[
+      AC_MSG_RESULT([yes])
+      tst_proto_setxattr="yes"
+    ],[
+      AC_MSG_RESULT([no])
+      tst_proto_setxattr="no"
+    ])
+  fi
+  #
+  if test "$tst_proto_setxattr" = "yes"; then
+    if test "$tst_nargs_setxattr" = "unknown"; then
+      AC_MSG_CHECKING([if setxattr takes 5 args.])
+      AC_COMPILE_IFELSE([
+        AC_LANG_PROGRAM([[
+          $curl_includes_sys_xattr
+        ]],[[
+          if(0 != setxattr(0, 0, 0, 0, 0))
+            return 1;
+        ]])
+      ],[
+        AC_MSG_RESULT([yes])
+        tst_compi_setxattr="yes"
+        tst_nargs_setxattr="5"
+      ],[
+        AC_MSG_RESULT([no])
+        tst_compi_setxattr="no"
+      ])
+    fi
+    if test "$tst_nargs_setxattr" = "unknown"; then
+      AC_MSG_CHECKING([if setxattr takes 6 args.])
+      AC_COMPILE_IFELSE([
+        AC_LANG_PROGRAM([[
+          $curl_includes_sys_xattr
+        ]],[[
+          if(0 != setxattr(0, 0, 0, 0, 0, 0))
+            return 1;
+        ]])
+      ],[
+        AC_MSG_RESULT([yes])
+        tst_compi_setxattr="yes"
+        tst_nargs_setxattr="6"
+      ],[
+        AC_MSG_RESULT([no])
+        tst_compi_setxattr="no"
+      ])
+    fi
+    AC_MSG_CHECKING([if setxattr is compilable])
+    if test "$tst_compi_setxattr" = "yes"; then
+      AC_MSG_RESULT([yes])
+    else
+      AC_MSG_RESULT([no])
+    fi
+  fi
+  #
+  if test "$tst_compi_setxattr" = "yes"; then
+    AC_MSG_CHECKING([if setxattr usage allowed])
+    if test "x$curl_disallow_setxattr" != "xyes"; then
+      AC_MSG_RESULT([yes])
+      tst_allow_setxattr="yes"
+    else
+      AC_MSG_RESULT([no])
+      tst_allow_setxattr="no"
+    fi
+  fi
+  #
+  AC_MSG_CHECKING([if setxattr might be used])
+  if test "$tst_links_setxattr" = "yes" &&
+     test "$tst_proto_setxattr" = "yes" &&
+     test "$tst_compi_setxattr" = "yes" &&
+     test "$tst_allow_setxattr" = "yes"; then
+    AC_MSG_RESULT([yes])
+    AC_DEFINE_UNQUOTED(HAVE_SETXATTR, 1,
+      [Define to 1 if you have the setxattr function.])
+    dnl AC_DEFINE_UNQUOTED(SETXATTR_ARGS, $tst_nargs_setxattr,
+    dnl   [Specifies the number of arguments to setxattr])
+    #
+    if test "$tst_nargs_setxattr" -eq "5"; then
+      AC_DEFINE(HAVE_SETXATTR_5, 1, [setxattr() takes 5 args])
+    elif test "$tst_nargs_setxattr" -eq "6"; then
+      AC_DEFINE(HAVE_SETXATTR_6, 1, [setxattr() takes 6 args])
+    fi
+    #
+    curl_cv_func_setxattr="yes"
+  else
+    AC_MSG_RESULT([no])
+    curl_cv_func_setxattr="no"
+  fi
+])
+
+
+dnl CURL_CHECK_FUNC_SIGACTION
+dnl -------------------------------------------------
+dnl Verify if sigaction is available, prototyped, and
+dnl can be compiled. If all of these are true, and
+dnl usage has not been previously disallowed with
+dnl shell variable curl_disallow_sigaction, then
+dnl HAVE_SIGACTION will be defined.
+
+AC_DEFUN([CURL_CHECK_FUNC_SIGACTION], [
+  AC_REQUIRE([CURL_INCLUDES_SIGNAL])dnl
+  #
+  tst_links_sigaction="unknown"
+  tst_proto_sigaction="unknown"
+  tst_compi_sigaction="unknown"
+  tst_allow_sigaction="unknown"
+  #
+  AC_MSG_CHECKING([if sigaction can be linked])
+  AC_LINK_IFELSE([
+    AC_LANG_FUNC_LINK_TRY([sigaction])
+  ],[
+    AC_MSG_RESULT([yes])
+    tst_links_sigaction="yes"
+  ],[
+    AC_MSG_RESULT([no])
+    tst_links_sigaction="no"
+  ])
+  #
+  if test "$tst_links_sigaction" = "yes"; then
+    AC_MSG_CHECKING([if sigaction is prototyped])
+    AC_EGREP_CPP([sigaction],[
+      $curl_includes_signal
+    ],[
+      AC_MSG_RESULT([yes])
+      tst_proto_sigaction="yes"
+    ],[
+      AC_MSG_RESULT([no])
+      tst_proto_sigaction="no"
+    ])
+  fi
+  #
+  if test "$tst_proto_sigaction" = "yes"; then
+    AC_MSG_CHECKING([if sigaction is compilable])
+    AC_COMPILE_IFELSE([
+      AC_LANG_PROGRAM([[
+        $curl_includes_signal
+      ]],[[
+        if(0 != sigaction(0, 0, 0))
+          return 1;
+      ]])
+    ],[
+      AC_MSG_RESULT([yes])
+      tst_compi_sigaction="yes"
+    ],[
+      AC_MSG_RESULT([no])
+      tst_compi_sigaction="no"
+    ])
+  fi
+  #
+  if test "$tst_compi_sigaction" = "yes"; then
+    AC_MSG_CHECKING([if sigaction usage allowed])
+    if test "x$curl_disallow_sigaction" != "xyes"; then
+      AC_MSG_RESULT([yes])
+      tst_allow_sigaction="yes"
+    else
+      AC_MSG_RESULT([no])
+      tst_allow_sigaction="no"
+    fi
+  fi
+  #
+  AC_MSG_CHECKING([if sigaction might be used])
+  if test "$tst_links_sigaction" = "yes" &&
+     test "$tst_proto_sigaction" = "yes" &&
+     test "$tst_compi_sigaction" = "yes" &&
+     test "$tst_allow_sigaction" = "yes"; then
+    AC_MSG_RESULT([yes])
+    AC_DEFINE_UNQUOTED(HAVE_SIGACTION, 1,
+      [Define to 1 if you have the sigaction function.])
+    curl_cv_func_sigaction="yes"
+  else
+    AC_MSG_RESULT([no])
+    curl_cv_func_sigaction="no"
+  fi
+])
+
+
+dnl CURL_CHECK_FUNC_SIGINTERRUPT
+dnl -------------------------------------------------
+dnl Verify if siginterrupt is available, prototyped, and
+dnl can be compiled. If all of these are true, and
+dnl usage has not been previously disallowed with
+dnl shell variable curl_disallow_siginterrupt, then
+dnl HAVE_SIGINTERRUPT will be defined.
+
+AC_DEFUN([CURL_CHECK_FUNC_SIGINTERRUPT], [
+  AC_REQUIRE([CURL_INCLUDES_SIGNAL])dnl
+  #
+  tst_links_siginterrupt="unknown"
+  tst_proto_siginterrupt="unknown"
+  tst_compi_siginterrupt="unknown"
+  tst_allow_siginterrupt="unknown"
+  #
+  AC_MSG_CHECKING([if siginterrupt can be linked])
+  AC_LINK_IFELSE([
+    AC_LANG_FUNC_LINK_TRY([siginterrupt])
+  ],[
+    AC_MSG_RESULT([yes])
+    tst_links_siginterrupt="yes"
+  ],[
+    AC_MSG_RESULT([no])
+    tst_links_siginterrupt="no"
+  ])
+  #
+  if test "$tst_links_siginterrupt" = "yes"; then
+    AC_MSG_CHECKING([if siginterrupt is prototyped])
+    AC_EGREP_CPP([siginterrupt],[
+      $curl_includes_signal
+    ],[
+      AC_MSG_RESULT([yes])
+      tst_proto_siginterrupt="yes"
+    ],[
+      AC_MSG_RESULT([no])
+      tst_proto_siginterrupt="no"
+    ])
+  fi
+  #
+  if test "$tst_proto_siginterrupt" = "yes"; then
+    AC_MSG_CHECKING([if siginterrupt is compilable])
+    AC_COMPILE_IFELSE([
+      AC_LANG_PROGRAM([[
+        $curl_includes_signal
+      ]],[[
+        if(0 != siginterrupt(0, 0))
+          return 1;
+      ]])
+    ],[
+      AC_MSG_RESULT([yes])
+      tst_compi_siginterrupt="yes"
+    ],[
+      AC_MSG_RESULT([no])
+      tst_compi_siginterrupt="no"
+    ])
+  fi
+  #
+  if test "$tst_compi_siginterrupt" = "yes"; then
+    AC_MSG_CHECKING([if siginterrupt usage allowed])
+    if test "x$curl_disallow_siginterrupt" != "xyes"; then
+      AC_MSG_RESULT([yes])
+      tst_allow_siginterrupt="yes"
+    else
+      AC_MSG_RESULT([no])
+      tst_allow_siginterrupt="no"
+    fi
+  fi
+  #
+  AC_MSG_CHECKING([if siginterrupt might be used])
+  if test "$tst_links_siginterrupt" = "yes" &&
+     test "$tst_proto_siginterrupt" = "yes" &&
+     test "$tst_compi_siginterrupt" = "yes" &&
+     test "$tst_allow_siginterrupt" = "yes"; then
+    AC_MSG_RESULT([yes])
+    AC_DEFINE_UNQUOTED(HAVE_SIGINTERRUPT, 1,
+      [Define to 1 if you have the siginterrupt function.])
+    curl_cv_func_siginterrupt="yes"
+  else
+    AC_MSG_RESULT([no])
+    curl_cv_func_siginterrupt="no"
+  fi
+])
+
+
+dnl CURL_CHECK_FUNC_SIGNAL
+dnl -------------------------------------------------
+dnl Verify if signal is available, prototyped, and
+dnl can be compiled. If all of these are true, and
+dnl usage has not been previously disallowed with
+dnl shell variable curl_disallow_signal, then
+dnl HAVE_SIGNAL will be defined.
+
+AC_DEFUN([CURL_CHECK_FUNC_SIGNAL], [
+  AC_REQUIRE([CURL_INCLUDES_SIGNAL])dnl
+  #
+  tst_links_signal="unknown"
+  tst_proto_signal="unknown"
+  tst_compi_signal="unknown"
+  tst_allow_signal="unknown"
+  #
+  AC_MSG_CHECKING([if signal can be linked])
+  AC_LINK_IFELSE([
+    AC_LANG_FUNC_LINK_TRY([signal])
+  ],[
+    AC_MSG_RESULT([yes])
+    tst_links_signal="yes"
+  ],[
+    AC_MSG_RESULT([no])
+    tst_links_signal="no"
+  ])
+  #
+  if test "$tst_links_signal" = "yes"; then
+    AC_MSG_CHECKING([if signal is prototyped])
+    AC_EGREP_CPP([signal],[
+      $curl_includes_signal
+    ],[
+      AC_MSG_RESULT([yes])
+      tst_proto_signal="yes"
+    ],[
+      AC_MSG_RESULT([no])
+      tst_proto_signal="no"
+    ])
+  fi
+  #
+  if test "$tst_proto_signal" = "yes"; then
+    AC_MSG_CHECKING([if signal is compilable])
+    AC_COMPILE_IFELSE([
+      AC_LANG_PROGRAM([[
+        $curl_includes_signal
+      ]],[[
+        if(0 != signal(0, 0))
+          return 1;
+      ]])
+    ],[
+      AC_MSG_RESULT([yes])
+      tst_compi_signal="yes"
+    ],[
+      AC_MSG_RESULT([no])
+      tst_compi_signal="no"
+    ])
+  fi
+  #
+  if test "$tst_compi_signal" = "yes"; then
+    AC_MSG_CHECKING([if signal usage allowed])
+    if test "x$curl_disallow_signal" != "xyes"; then
+      AC_MSG_RESULT([yes])
+      tst_allow_signal="yes"
+    else
+      AC_MSG_RESULT([no])
+      tst_allow_signal="no"
+    fi
+  fi
+  #
+  AC_MSG_CHECKING([if signal might be used])
+  if test "$tst_links_signal" = "yes" &&
+     test "$tst_proto_signal" = "yes" &&
+     test "$tst_compi_signal" = "yes" &&
+     test "$tst_allow_signal" = "yes"; then
+    AC_MSG_RESULT([yes])
+    AC_DEFINE_UNQUOTED(HAVE_SIGNAL, 1,
+      [Define to 1 if you have the signal function.])
+    curl_cv_func_signal="yes"
+  else
+    AC_MSG_RESULT([no])
+    curl_cv_func_signal="no"
+  fi
+])
+
+
+dnl CURL_CHECK_FUNC_SIGSETJMP
+dnl -------------------------------------------------
+dnl Verify if sigsetjmp is available, prototyped, and
+dnl can be compiled. If all of these are true, and
+dnl usage has not been previously disallowed with
+dnl shell variable curl_disallow_sigsetjmp, then
+dnl HAVE_SIGSETJMP will be defined.
+
+AC_DEFUN([CURL_CHECK_FUNC_SIGSETJMP], [
+  AC_REQUIRE([CURL_INCLUDES_SETJMP])dnl
+  #
+  tst_links_sigsetjmp="unknown"
+  tst_macro_sigsetjmp="unknown"
+  tst_proto_sigsetjmp="unknown"
+  tst_compi_sigsetjmp="unknown"
+  tst_allow_sigsetjmp="unknown"
+  #
+  AC_MSG_CHECKING([if sigsetjmp can be linked])
+  AC_LINK_IFELSE([
+    AC_LANG_FUNC_LINK_TRY([sigsetjmp])
+  ],[
+    AC_MSG_RESULT([yes])
+    tst_links_sigsetjmp="yes"
+  ],[
+    AC_MSG_RESULT([no])
+    tst_links_sigsetjmp="no"
+  ])
+  #
+  if test "$tst_links_sigsetjmp" = "no"; then
+    AC_MSG_CHECKING([if sigsetjmp seems a macro])
+    AC_LINK_IFELSE([
+      AC_LANG_PROGRAM([[
+        $curl_includes_setjmp
+      ]],[[
+        sigjmp_buf env;
+        if(0 != sigsetjmp(env, 0))
+          return 1;
+      ]])
+    ],[
+      AC_MSG_RESULT([yes])
+      tst_macro_sigsetjmp="yes"
+    ],[
+      AC_MSG_RESULT([no])
+      tst_macro_sigsetjmp="no"
+    ])
+  fi
+  #
+  if test "$tst_links_sigsetjmp" = "yes"; then
+    AC_MSG_CHECKING([if sigsetjmp is prototyped])
+    AC_EGREP_CPP([sigsetjmp],[
+      $curl_includes_setjmp
+    ],[
+      AC_MSG_RESULT([yes])
+      tst_proto_sigsetjmp="yes"
+    ],[
+      AC_MSG_RESULT([no])
+      tst_proto_sigsetjmp="no"
+    ])
+  fi
+  #
+  if test "$tst_proto_sigsetjmp" = "yes" ||
+     test "$tst_macro_sigsetjmp" = "yes"; then
+    AC_MSG_CHECKING([if sigsetjmp is compilable])
+    AC_COMPILE_IFELSE([
+      AC_LANG_PROGRAM([[
+        $curl_includes_setjmp
+      ]],[[
+        sigjmp_buf env;
+        if(0 != sigsetjmp(env, 0))
+          return 1;
+      ]])
+    ],[
+      AC_MSG_RESULT([yes])
+      tst_compi_sigsetjmp="yes"
+    ],[
+      AC_MSG_RESULT([no])
+      tst_compi_sigsetjmp="no"
+    ])
+  fi
+  #
+  if test "$tst_compi_sigsetjmp" = "yes"; then
+    AC_MSG_CHECKING([if sigsetjmp usage allowed])
+    if test "x$curl_disallow_sigsetjmp" != "xyes"; then
+      AC_MSG_RESULT([yes])
+      tst_allow_sigsetjmp="yes"
+    else
+      AC_MSG_RESULT([no])
+      tst_allow_sigsetjmp="no"
+    fi
+  fi
+  #
+  AC_MSG_CHECKING([if sigsetjmp might be used])
+  if (test "$tst_proto_sigsetjmp" = "yes" ||
+      test "$tst_macro_sigsetjmp" = "yes") &&
+     test "$tst_compi_sigsetjmp" = "yes" &&
+     test "$tst_allow_sigsetjmp" = "yes"; then
+    AC_MSG_RESULT([yes])
+    AC_DEFINE_UNQUOTED(HAVE_SIGSETJMP, 1,
+      [Define to 1 if you have the sigsetjmp function or macro.])
+    curl_cv_func_sigsetjmp="yes"
+  else
+    AC_MSG_RESULT([no])
+    curl_cv_func_sigsetjmp="no"
+  fi
+])
+
+
+dnl CURL_CHECK_FUNC_SOCKET
+dnl -------------------------------------------------
+dnl Verify if socket is available, prototyped, and
+dnl can be compiled. If all of these are true, and
+dnl usage has not been previously disallowed with
+dnl shell variable curl_disallow_socket, then
+dnl HAVE_SOCKET will be defined.
+
+AC_DEFUN([CURL_CHECK_FUNC_SOCKET], [
+  AC_REQUIRE([CURL_INCLUDES_WINSOCK2])dnl
+  AC_REQUIRE([CURL_INCLUDES_SYS_SOCKET])dnl
+  AC_REQUIRE([CURL_INCLUDES_SOCKET])dnl
+  #
+  tst_links_socket="unknown"
+  tst_proto_socket="unknown"
+  tst_compi_socket="unknown"
+  tst_allow_socket="unknown"
+  #
+  AC_MSG_CHECKING([if socket can be linked])
+  AC_LINK_IFELSE([
+    AC_LANG_PROGRAM([[
+      $curl_includes_winsock2
+      $curl_includes_sys_socket
+      $curl_includes_socket
+    ]],[[
+      if(0 != socket(0, 0, 0))
+        return 1;
+    ]])
+  ],[
+    AC_MSG_RESULT([yes])
+    tst_links_socket="yes"
+  ],[
+    AC_MSG_RESULT([no])
+    tst_links_socket="no"
+  ])
+  #
+  if test "$tst_links_socket" = "yes"; then
+    AC_MSG_CHECKING([if socket is prototyped])
+    AC_EGREP_CPP([socket],[
+      $curl_includes_winsock2
+      $curl_includes_sys_socket
+      $curl_includes_socket
+    ],[
+      AC_MSG_RESULT([yes])
+      tst_proto_socket="yes"
+    ],[
+      AC_MSG_RESULT([no])
+      tst_proto_socket="no"
+    ])
+  fi
+  #
+  if test "$tst_proto_socket" = "yes"; then
+    AC_MSG_CHECKING([if socket is compilable])
+    AC_COMPILE_IFELSE([
+      AC_LANG_PROGRAM([[
+        $curl_includes_winsock2
+        $curl_includes_sys_socket
+        $curl_includes_socket
+      ]],[[
+        if(0 != socket(0, 0, 0))
+          return 1;
+      ]])
+    ],[
+      AC_MSG_RESULT([yes])
+      tst_compi_socket="yes"
+    ],[
+      AC_MSG_RESULT([no])
+      tst_compi_socket="no"
+    ])
+  fi
+  #
+  if test "$tst_compi_socket" = "yes"; then
+    AC_MSG_CHECKING([if socket usage allowed])
+    if test "x$curl_disallow_socket" != "xyes"; then
+      AC_MSG_RESULT([yes])
+      tst_allow_socket="yes"
+    else
+      AC_MSG_RESULT([no])
+      tst_allow_socket="no"
+    fi
+  fi
+  #
+  AC_MSG_CHECKING([if socket might be used])
+  if test "$tst_links_socket" = "yes" &&
+     test "$tst_proto_socket" = "yes" &&
+     test "$tst_compi_socket" = "yes" &&
+     test "$tst_allow_socket" = "yes"; then
+    AC_MSG_RESULT([yes])
+    AC_DEFINE_UNQUOTED(HAVE_SOCKET, 1,
+      [Define to 1 if you have the socket function.])
+    curl_cv_func_socket="yes"
+  else
+    AC_MSG_RESULT([no])
+    curl_cv_func_socket="no"
+  fi
+])
+
+
+dnl CURL_CHECK_FUNC_SOCKETPAIR
+dnl -------------------------------------------------
+dnl Verify if socketpair is available, prototyped, and
+dnl can be compiled. If all of these are true, and
+dnl usage has not been previously disallowed with
+dnl shell variable curl_disallow_socketpair, then
+dnl HAVE_SOCKETPAIR will be defined.
+
+AC_DEFUN([CURL_CHECK_FUNC_SOCKETPAIR], [
+  AC_REQUIRE([CURL_INCLUDES_SYS_SOCKET])dnl
+  AC_REQUIRE([CURL_INCLUDES_SOCKET])dnl
+  #
+  tst_links_socketpair="unknown"
+  tst_proto_socketpair="unknown"
+  tst_compi_socketpair="unknown"
+  tst_allow_socketpair="unknown"
+  #
+  AC_MSG_CHECKING([if socketpair can be linked])
+  AC_LINK_IFELSE([
+    AC_LANG_FUNC_LINK_TRY([socketpair])
+  ],[
+    AC_MSG_RESULT([yes])
+    tst_links_socketpair="yes"
+  ],[
+    AC_MSG_RESULT([no])
+    tst_links_socketpair="no"
+  ])
+  #
+  if test "$tst_links_socketpair" = "yes"; then
+    AC_MSG_CHECKING([if socketpair is prototyped])
+    AC_EGREP_CPP([socketpair],[
+      $curl_includes_sys_socket
+      $curl_includes_socket
+    ],[
+      AC_MSG_RESULT([yes])
+      tst_proto_socketpair="yes"
+    ],[
+      AC_MSG_RESULT([no])
+      tst_proto_socketpair="no"
+    ])
+  fi
+  #
+  if test "$tst_proto_socketpair" = "yes"; then
+    AC_MSG_CHECKING([if socketpair is compilable])
+    AC_COMPILE_IFELSE([
+      AC_LANG_PROGRAM([[
+        $curl_includes_sys_socket
+        $curl_includes_socket
+      ]],[[
+        int sv[2];
+        if(0 != socketpair(0, 0, 0, sv))
+          return 1;
+      ]])
+    ],[
+      AC_MSG_RESULT([yes])
+      tst_compi_socketpair="yes"
+    ],[
+      AC_MSG_RESULT([no])
+      tst_compi_socketpair="no"
+    ])
+  fi
+  #
+  if test "$tst_compi_socketpair" = "yes"; then
+    AC_MSG_CHECKING([if socketpair usage allowed])
+    if test "x$curl_disallow_socketpair" != "xyes"; then
+      AC_MSG_RESULT([yes])
+      tst_allow_socketpair="yes"
+    else
+      AC_MSG_RESULT([no])
+      tst_allow_socketpair="no"
+    fi
+  fi
+  #
+  AC_MSG_CHECKING([if socketpair might be used])
+  if test "$tst_links_socketpair" = "yes" &&
+     test "$tst_proto_socketpair" = "yes" &&
+     test "$tst_compi_socketpair" = "yes" &&
+     test "$tst_allow_socketpair" = "yes"; then
+    AC_MSG_RESULT([yes])
+    AC_DEFINE_UNQUOTED(HAVE_SOCKETPAIR, 1,
+      [Define to 1 if you have the socketpair function.])
+    curl_cv_func_socketpair="yes"
+  else
+    AC_MSG_RESULT([no])
+    curl_cv_func_socketpair="no"
+  fi
+])
+
+
+dnl CURL_CHECK_FUNC_STRCASECMP
+dnl -------------------------------------------------
+dnl Verify if strcasecmp is available, prototyped, and
+dnl can be compiled. If all of these are true, and
+dnl usage has not been previously disallowed with
+dnl shell variable curl_disallow_strcasecmp, then
+dnl HAVE_STRCASECMP will be defined.
+
+AC_DEFUN([CURL_CHECK_FUNC_STRCASECMP], [
+  AC_REQUIRE([CURL_INCLUDES_STRING])dnl
+  #
+  tst_links_strcasecmp="unknown"
+  tst_proto_strcasecmp="unknown"
+  tst_compi_strcasecmp="unknown"
+  tst_allow_strcasecmp="unknown"
+  #
+  AC_MSG_CHECKING([if strcasecmp can be linked])
+  AC_LINK_IFELSE([
+    AC_LANG_FUNC_LINK_TRY([strcasecmp])
+  ],[
+    AC_MSG_RESULT([yes])
+    tst_links_strcasecmp="yes"
+  ],[
+    AC_MSG_RESULT([no])
+    tst_links_strcasecmp="no"
+  ])
+  #
+  if test "$tst_links_strcasecmp" = "yes"; then
+    AC_MSG_CHECKING([if strcasecmp is prototyped])
+    AC_EGREP_CPP([strcasecmp],[
+      $curl_includes_string
+    ],[
+      AC_MSG_RESULT([yes])
+      tst_proto_strcasecmp="yes"
+    ],[
+      AC_MSG_RESULT([no])
+      tst_proto_strcasecmp="no"
+    ])
+  fi
+  #
+  if test "$tst_proto_strcasecmp" = "yes"; then
+    AC_MSG_CHECKING([if strcasecmp is compilable])
+    AC_COMPILE_IFELSE([
+      AC_LANG_PROGRAM([[
+        $curl_includes_string
+      ]],[[
+        if(0 != strcasecmp(0, 0))
+          return 1;
+      ]])
+    ],[
+      AC_MSG_RESULT([yes])
+      tst_compi_strcasecmp="yes"
+    ],[
+      AC_MSG_RESULT([no])
+      tst_compi_strcasecmp="no"
+    ])
+  fi
+  #
+  if test "$tst_compi_strcasecmp" = "yes"; then
+    AC_MSG_CHECKING([if strcasecmp usage allowed])
+    if test "x$curl_disallow_strcasecmp" != "xyes"; then
+      AC_MSG_RESULT([yes])
+      tst_allow_strcasecmp="yes"
+    else
+      AC_MSG_RESULT([no])
+      tst_allow_strcasecmp="no"
+    fi
+  fi
+  #
+  AC_MSG_CHECKING([if strcasecmp might be used])
+  if test "$tst_links_strcasecmp" = "yes" &&
+     test "$tst_proto_strcasecmp" = "yes" &&
+     test "$tst_compi_strcasecmp" = "yes" &&
+     test "$tst_allow_strcasecmp" = "yes"; then
+    AC_MSG_RESULT([yes])
+    AC_DEFINE_UNQUOTED(HAVE_STRCASECMP, 1,
+      [Define to 1 if you have the strcasecmp function.])
+    curl_cv_func_strcasecmp="yes"
+  else
+    AC_MSG_RESULT([no])
+    curl_cv_func_strcasecmp="no"
+  fi
+])
+
+dnl CURL_CHECK_FUNC_STRCMPI
+dnl -------------------------------------------------
+dnl Verify if strcmpi is available, prototyped, and
+dnl can be compiled. If all of these are true, and
+dnl usage has not been previously disallowed with
+dnl shell variable curl_disallow_strcmpi, then
+dnl HAVE_STRCMPI will be defined.
+
+AC_DEFUN([CURL_CHECK_FUNC_STRCMPI], [
+  AC_REQUIRE([CURL_INCLUDES_STRING])dnl
+  #
+  tst_links_strcmpi="unknown"
+  tst_proto_strcmpi="unknown"
+  tst_compi_strcmpi="unknown"
+  tst_allow_strcmpi="unknown"
+  #
+  AC_MSG_CHECKING([if strcmpi can be linked])
+  AC_LINK_IFELSE([
+    AC_LANG_FUNC_LINK_TRY([strcmpi])
+  ],[
+    AC_MSG_RESULT([yes])
+    tst_links_strcmpi="yes"
+  ],[
+    AC_MSG_RESULT([no])
+    tst_links_strcmpi="no"
+  ])
+  #
+  if test "$tst_links_strcmpi" = "yes"; then
+    AC_MSG_CHECKING([if strcmpi is prototyped])
+    AC_EGREP_CPP([strcmpi],[
+      $curl_includes_string
+    ],[
+      AC_MSG_RESULT([yes])
+      tst_proto_strcmpi="yes"
+    ],[
+      AC_MSG_RESULT([no])
+      tst_proto_strcmpi="no"
+    ])
+  fi
+  #
+  if test "$tst_proto_strcmpi" = "yes"; then
+    AC_MSG_CHECKING([if strcmpi is compilable])
+    AC_COMPILE_IFELSE([
+      AC_LANG_PROGRAM([[
+        $curl_includes_string
+      ]],[[
+        if(0 != strcmpi(0, 0))
+          return 1;
+      ]])
+    ],[
+      AC_MSG_RESULT([yes])
+      tst_compi_strcmpi="yes"
+    ],[
+      AC_MSG_RESULT([no])
+      tst_compi_strcmpi="no"
+    ])
+  fi
+  #
+  if test "$tst_compi_strcmpi" = "yes"; then
+    AC_MSG_CHECKING([if strcmpi usage allowed])
+    if test "x$curl_disallow_strcmpi" != "xyes"; then
+      AC_MSG_RESULT([yes])
+      tst_allow_strcmpi="yes"
+    else
+      AC_MSG_RESULT([no])
+      tst_allow_strcmpi="no"
+    fi
+  fi
+  #
+  AC_MSG_CHECKING([if strcmpi might be used])
+  if test "$tst_links_strcmpi" = "yes" &&
+     test "$tst_proto_strcmpi" = "yes" &&
+     test "$tst_compi_strcmpi" = "yes" &&
+     test "$tst_allow_strcmpi" = "yes"; then
+    AC_MSG_RESULT([yes])
+    AC_DEFINE_UNQUOTED(HAVE_STRCMPI, 1,
+      [Define to 1 if you have the strcmpi function.])
+    curl_cv_func_strcmpi="yes"
+  else
+    AC_MSG_RESULT([no])
+    curl_cv_func_strcmpi="no"
+  fi
+])
+
+
+dnl CURL_CHECK_FUNC_STRDUP
+dnl -------------------------------------------------
+dnl Verify if strdup is available, prototyped, and
+dnl can be compiled. If all of these are true, and
+dnl usage has not been previously disallowed with
+dnl shell variable curl_disallow_strdup, then
+dnl HAVE_STRDUP will be defined.
+
+AC_DEFUN([CURL_CHECK_FUNC_STRDUP], [
+  AC_REQUIRE([CURL_INCLUDES_STRING])dnl
+  #
+  tst_links_strdup="unknown"
+  tst_proto_strdup="unknown"
+  tst_compi_strdup="unknown"
+  tst_allow_strdup="unknown"
+  #
+  AC_MSG_CHECKING([if strdup can be linked])
+  AC_LINK_IFELSE([
+    AC_LANG_FUNC_LINK_TRY([strdup])
+  ],[
+    AC_MSG_RESULT([yes])
+    tst_links_strdup="yes"
+  ],[
+    AC_MSG_RESULT([no])
+    tst_links_strdup="no"
+  ])
+  #
+  if test "$tst_links_strdup" = "yes"; then
+    AC_MSG_CHECKING([if strdup is prototyped])
+    AC_EGREP_CPP([strdup],[
+      $curl_includes_string
+    ],[
+      AC_MSG_RESULT([yes])
+      tst_proto_strdup="yes"
+    ],[
+      AC_MSG_RESULT([no])
+      tst_proto_strdup="no"
+    ])
+  fi
+  #
+  if test "$tst_proto_strdup" = "yes"; then
+    AC_MSG_CHECKING([if strdup is compilable])
+    AC_COMPILE_IFELSE([
+      AC_LANG_PROGRAM([[
+        $curl_includes_string
+      ]],[[
+        if(0 != strdup(0))
+          return 1;
+      ]])
+    ],[
+      AC_MSG_RESULT([yes])
+      tst_compi_strdup="yes"
+    ],[
+      AC_MSG_RESULT([no])
+      tst_compi_strdup="no"
+    ])
+  fi
+  #
+  if test "$tst_compi_strdup" = "yes"; then
+    AC_MSG_CHECKING([if strdup usage allowed])
+    if test "x$curl_disallow_strdup" != "xyes"; then
+      AC_MSG_RESULT([yes])
+      tst_allow_strdup="yes"
+    else
+      AC_MSG_RESULT([no])
+      tst_allow_strdup="no"
+    fi
+  fi
+  #
+  AC_MSG_CHECKING([if strdup might be used])
+  if test "$tst_links_strdup" = "yes" &&
+     test "$tst_proto_strdup" = "yes" &&
+     test "$tst_compi_strdup" = "yes" &&
+     test "$tst_allow_strdup" = "yes"; then
+    AC_MSG_RESULT([yes])
+    AC_DEFINE_UNQUOTED(HAVE_STRDUP, 1,
+      [Define to 1 if you have the strdup function.])
+    curl_cv_func_strdup="yes"
+  else
+    AC_MSG_RESULT([no])
+    curl_cv_func_strdup="no"
+  fi
+])
+
+
+dnl CURL_CHECK_FUNC_STRERROR_R
+dnl -------------------------------------------------
+dnl Verify if strerror_r is available, prototyped, can be compiled and
+dnl seems to work. If all of these are true, and usage has not been
+dnl previously disallowed with shell variable curl_disallow_strerror_r,
+dnl then HAVE_STRERROR_R and STRERROR_R_TYPE_ARG3 will be defined, as
+dnl well as one of HAVE_GLIBC_STRERROR_R or HAVE_POSIX_STRERROR_R.
+dnl
+dnl glibc-style strerror_r:
+dnl
+dnl      char *strerror_r(int errnum, char *workbuf, size_t bufsize);
+dnl
+dnl  glibc-style strerror_r returns a pointer to the the error string,
+dnl  and might use the provided workbuf as a scratch area if needed. A
+dnl  quick test on a few systems shows that it's usually not used at all.
+dnl
+dnl POSIX-style strerror_r:
+dnl
+dnl      int strerror_r(int errnum, char *resultbuf, size_t bufsize);
+dnl
+dnl  POSIX-style strerror_r returns 0 upon successful completion and the
+dnl  error string in the provided resultbuf.
+dnl
+
+AC_DEFUN([CURL_CHECK_FUNC_STRERROR_R], [
+  AC_REQUIRE([CURL_INCLUDES_STDLIB])dnl
+  AC_REQUIRE([CURL_INCLUDES_STRING])dnl
+  #
+  tst_links_strerror_r="unknown"
+  tst_proto_strerror_r="unknown"
+  tst_compi_strerror_r="unknown"
+  tst_glibc_strerror_r="unknown"
+  tst_posix_strerror_r="unknown"
+  tst_allow_strerror_r="unknown"
+  tst_works_glibc_strerror_r="unknown"
+  tst_works_posix_strerror_r="unknown"
+  tst_glibc_strerror_r_type_arg3="unknown"
+  tst_posix_strerror_r_type_arg3="unknown"
+  #
+  AC_MSG_CHECKING([if strerror_r can be linked])
+  AC_LINK_IFELSE([
+    AC_LANG_FUNC_LINK_TRY([strerror_r])
+  ],[
+    AC_MSG_RESULT([yes])
+    tst_links_strerror_r="yes"
+  ],[
+    AC_MSG_RESULT([no])
+    tst_links_strerror_r="no"
+  ])
+  #
+  if test "$tst_links_strerror_r" = "yes"; then
+    AC_MSG_CHECKING([if strerror_r is prototyped])
+    AC_EGREP_CPP([strerror_r],[
+      $curl_includes_string
+    ],[
+      AC_MSG_RESULT([yes])
+      tst_proto_strerror_r="yes"
+    ],[
+      AC_MSG_RESULT([no])
+      tst_proto_strerror_r="no"
+    ])
+  fi
+  #
+  if test "$tst_proto_strerror_r" = "yes"; then
+    AC_MSG_CHECKING([if strerror_r is compilable])
+    AC_COMPILE_IFELSE([
+      AC_LANG_PROGRAM([[
+        $curl_includes_string
+      ]],[[
+        if(0 != strerror_r(0, 0, 0))
+          return 1;
+      ]])
+    ],[
+      AC_MSG_RESULT([yes])
+      tst_compi_strerror_r="yes"
+    ],[
+      AC_MSG_RESULT([no])
+      tst_compi_strerror_r="no"
+    ])
+  fi
+  #
+  if test "$tst_compi_strerror_r" = "yes"; then
+    AC_MSG_CHECKING([if strerror_r is glibc like])
+    tst_glibc_strerror_r_type_arg3="unknown"
+    for arg3 in 'size_t' 'int' 'unsigned int'; do
+      if test "$tst_glibc_strerror_r_type_arg3" = "unknown"; then
+        AC_COMPILE_IFELSE([
+          AC_LANG_PROGRAM([[
+            $curl_includes_string
+            char *strerror_r(int errnum, char *workbuf, $arg3 bufsize);
+          ]],[[
+            if(0 != strerror_r(0, 0, 0))
+              return 1;
+          ]])
+        ],[
+          tst_glibc_strerror_r_type_arg3="$arg3"
+        ])
+      fi
+    done
+    case "$tst_glibc_strerror_r_type_arg3" in
+      unknown)
+        AC_MSG_RESULT([no])
+        tst_glibc_strerror_r="no"
+        ;;
+      *)
+        AC_MSG_RESULT([yes])
+        tst_glibc_strerror_r="yes"
+        ;;
+    esac
+  fi
+  #
+  dnl only do runtime verification when not cross-compiling
+  if test "x$cross_compiling" != "xyes" &&
+    test "$tst_glibc_strerror_r" = "yes"; then
+    AC_MSG_CHECKING([if strerror_r seems to work])
+    AC_RUN_IFELSE([
+      AC_LANG_PROGRAM([[
+        $curl_includes_stdlib
+        $curl_includes_string
+#       include <errno.h>
+      ]],[[
+        char buffer[1024];
+        char *string = 0;
+        buffer[0] = '\0';
+        string = strerror_r(EACCES, buffer, sizeof(buffer));
+        if(!string)
+          exit(1); /* fail */
+        if(!string[0])
+          exit(1); /* fail */
+        else
+          exit(0);
+      ]])
+    ],[
+      AC_MSG_RESULT([yes])
+      tst_works_glibc_strerror_r="yes"
+    ],[
+      AC_MSG_RESULT([no])
+      tst_works_glibc_strerror_r="no"
+    ])
+  fi
+  #
+  if test "$tst_compi_strerror_r" = "yes" &&
+    test "$tst_works_glibc_strerror_r" != "yes"; then
+    AC_MSG_CHECKING([if strerror_r is POSIX like])
+    tst_posix_strerror_r_type_arg3="unknown"
+    for arg3 in 'size_t' 'int' 'unsigned int'; do
+      if test "$tst_posix_strerror_r_type_arg3" = "unknown"; then
+        AC_COMPILE_IFELSE([
+          AC_LANG_PROGRAM([[
+            $curl_includes_string
+            int strerror_r(int errnum, char *resultbuf, $arg3 bufsize);
+          ]],[[
+            if(0 != strerror_r(0, 0, 0))
+              return 1;
+          ]])
+        ],[
+          tst_posix_strerror_r_type_arg3="$arg3"
+        ])
+      fi
+    done
+    case "$tst_posix_strerror_r_type_arg3" in
+      unknown)
+        AC_MSG_RESULT([no])
+        tst_posix_strerror_r="no"
+        ;;
+      *)
+        AC_MSG_RESULT([yes])
+        tst_posix_strerror_r="yes"
+        ;;
+    esac
+  fi
+  #
+  dnl only do runtime verification when not cross-compiling
+  if test "x$cross_compiling" != "xyes" &&
+    test "$tst_posix_strerror_r" = "yes"; then
+    AC_MSG_CHECKING([if strerror_r seems to work])
+    AC_RUN_IFELSE([
+      AC_LANG_PROGRAM([[
+        $curl_includes_stdlib
+        $curl_includes_string
+#       include <errno.h>
+      ]],[[
+        char buffer[1024];
+        int error = 1;
+        buffer[0] = '\0';
+        error = strerror_r(EACCES, buffer, sizeof(buffer));
+        if(error)
+          exit(1); /* fail */
+        if(buffer[0] == '\0')
+          exit(1); /* fail */
+        else
+          exit(0);
+      ]])
+    ],[
+      AC_MSG_RESULT([yes])
+      tst_works_posix_strerror_r="yes"
+    ],[
+      AC_MSG_RESULT([no])
+      tst_works_posix_strerror_r="no"
+    ])
+  fi
+  #
+  if test "$tst_works_glibc_strerror_r" = "yes"; then
+    tst_posix_strerror_r="no"
+  fi
+  if test "$tst_works_posix_strerror_r" = "yes"; then
+    tst_glibc_strerror_r="no"
+  fi
+  if test "$tst_glibc_strerror_r" = "yes" &&
+    test "$tst_works_glibc_strerror_r" != "no" &&
+    test "$tst_posix_strerror_r" != "yes"; then
+    tst_allow_strerror_r="check"
+  fi
+  if test "$tst_posix_strerror_r" = "yes" &&
+    test "$tst_works_posix_strerror_r" != "no" &&
+    test "$tst_glibc_strerror_r" != "yes"; then
+    tst_allow_strerror_r="check"
+  fi
+  if test "$tst_allow_strerror_r" = "check"; then
+    AC_MSG_CHECKING([if strerror_r usage allowed])
+    if test "x$curl_disallow_strerror_r" != "xyes"; then
+      AC_MSG_RESULT([yes])
+      tst_allow_strerror_r="yes"
+    else
+      AC_MSG_RESULT([no])
+      tst_allow_strerror_r="no"
+    fi
+  fi
+  #
+  AC_MSG_CHECKING([if strerror_r might be used])
+  if test "$tst_links_strerror_r" = "yes" &&
+     test "$tst_proto_strerror_r" = "yes" &&
+     test "$tst_compi_strerror_r" = "yes" &&
+     test "$tst_allow_strerror_r" = "yes"; then
+    AC_MSG_RESULT([yes])
+    if test "$tst_glibc_strerror_r" = "yes"; then
+      AC_DEFINE_UNQUOTED(HAVE_STRERROR_R, 1,
+        [Define to 1 if you have the strerror_r function.])
+      AC_DEFINE_UNQUOTED(HAVE_GLIBC_STRERROR_R, 1,
+        [Define to 1 if you have a working glibc-style strerror_r function.])
+      AC_DEFINE_UNQUOTED(STRERROR_R_TYPE_ARG3, $tst_glibc_strerror_r_type_arg3,
+        [Define to the type of arg 3 for strerror_r.])
+    fi
+    if test "$tst_posix_strerror_r" = "yes"; then
+      AC_DEFINE_UNQUOTED(HAVE_STRERROR_R, 1,
+        [Define to 1 if you have the strerror_r function.])
+      AC_DEFINE_UNQUOTED(HAVE_POSIX_STRERROR_R, 1,
+        [Define to 1 if you have a working POSIX-style strerror_r function.])
+      AC_DEFINE_UNQUOTED(STRERROR_R_TYPE_ARG3, $tst_posix_strerror_r_type_arg3,
+        [Define to the type of arg 3 for strerror_r.])
+    fi
+    curl_cv_func_strerror_r="yes"
+  else
+    AC_MSG_RESULT([no])
+    curl_cv_func_strerror_r="no"
+  fi
+  #
+  if test "$tst_compi_strerror_r" = "yes" &&
+     test "$tst_allow_strerror_r" = "unknown"; then
+    AC_MSG_WARN([cannot determine strerror_r() style: edit lib/curl_config.h manually.])
+  fi
+  #
+])
+
+
+dnl CURL_CHECK_FUNC_STRICMP
+dnl -------------------------------------------------
+dnl Verify if stricmp is available, prototyped, and
+dnl can be compiled. If all of these are true, and
+dnl usage has not been previously disallowed with
+dnl shell variable curl_disallow_stricmp, then
+dnl HAVE_STRICMP will be defined.
+
+AC_DEFUN([CURL_CHECK_FUNC_STRICMP], [
+  AC_REQUIRE([CURL_INCLUDES_STRING])dnl
+  #
+  tst_links_stricmp="unknown"
+  tst_proto_stricmp="unknown"
+  tst_compi_stricmp="unknown"
+  tst_allow_stricmp="unknown"
+  #
+  AC_MSG_CHECKING([if stricmp can be linked])
+  AC_LINK_IFELSE([
+    AC_LANG_FUNC_LINK_TRY([stricmp])
+  ],[
+    AC_MSG_RESULT([yes])
+    tst_links_stricmp="yes"
+  ],[
+    AC_MSG_RESULT([no])
+    tst_links_stricmp="no"
+  ])
+  #
+  if test "$tst_links_stricmp" = "yes"; then
+    AC_MSG_CHECKING([if stricmp is prototyped])
+    AC_EGREP_CPP([stricmp],[
+      $curl_includes_string
+    ],[
+      AC_MSG_RESULT([yes])
+      tst_proto_stricmp="yes"
+    ],[
+      AC_MSG_RESULT([no])
+      tst_proto_stricmp="no"
+    ])
+  fi
+  #
+  if test "$tst_proto_stricmp" = "yes"; then
+    AC_MSG_CHECKING([if stricmp is compilable])
+    AC_COMPILE_IFELSE([
+      AC_LANG_PROGRAM([[
+        $curl_includes_string
+      ]],[[
+        if(0 != stricmp(0, 0))
+          return 1;
+      ]])
+    ],[
+      AC_MSG_RESULT([yes])
+      tst_compi_stricmp="yes"
+    ],[
+      AC_MSG_RESULT([no])
+      tst_compi_stricmp="no"
+    ])
+  fi
+  #
+  if test "$tst_compi_stricmp" = "yes"; then
+    AC_MSG_CHECKING([if stricmp usage allowed])
+    if test "x$curl_disallow_stricmp" != "xyes"; then
+      AC_MSG_RESULT([yes])
+      tst_allow_stricmp="yes"
+    else
+      AC_MSG_RESULT([no])
+      tst_allow_stricmp="no"
+    fi
+  fi
+  #
+  AC_MSG_CHECKING([if stricmp might be used])
+  if test "$tst_links_stricmp" = "yes" &&
+     test "$tst_proto_stricmp" = "yes" &&
+     test "$tst_compi_stricmp" = "yes" &&
+     test "$tst_allow_stricmp" = "yes"; then
+    AC_MSG_RESULT([yes])
+    AC_DEFINE_UNQUOTED(HAVE_STRICMP, 1,
+      [Define to 1 if you have the stricmp function.])
+    curl_cv_func_stricmp="yes"
+  else
+    AC_MSG_RESULT([no])
+    curl_cv_func_stricmp="no"
+  fi
+])
+
+dnl CURL_CHECK_FUNC_STRNCASECMP
+dnl -------------------------------------------------
+dnl Verify if strncasecmp is available, prototyped, and
+dnl can be compiled. If all of these are true, and
+dnl usage has not been previously disallowed with
+dnl shell variable curl_disallow_strncasecmp, then
+dnl HAVE_STRNCASECMP will be defined.
+
+AC_DEFUN([CURL_CHECK_FUNC_STRNCASECMP], [
+  AC_REQUIRE([CURL_INCLUDES_STRING])dnl
+  #
+  tst_links_strncasecmp="unknown"
+  tst_proto_strncasecmp="unknown"
+  tst_compi_strncasecmp="unknown"
+  tst_allow_strncasecmp="unknown"
+  #
+  AC_MSG_CHECKING([if strncasecmp can be linked])
+  AC_LINK_IFELSE([
+    AC_LANG_FUNC_LINK_TRY([strncasecmp])
+  ],[
+    AC_MSG_RESULT([yes])
+    tst_links_strncasecmp="yes"
+  ],[
+    AC_MSG_RESULT([no])
+    tst_links_strncasecmp="no"
+  ])
+  #
+  if test "$tst_links_strncasecmp" = "yes"; then
+    AC_MSG_CHECKING([if strncasecmp is prototyped])
+    AC_EGREP_CPP([strncasecmp],[
+      $curl_includes_string
+    ],[
+      AC_MSG_RESULT([yes])
+      tst_proto_strncasecmp="yes"
+    ],[
+      AC_MSG_RESULT([no])
+      tst_proto_strncasecmp="no"
+    ])
+  fi
+  #
+  if test "$tst_proto_strncasecmp" = "yes"; then
+    AC_MSG_CHECKING([if strncasecmp is compilable])
+    AC_COMPILE_IFELSE([
+      AC_LANG_PROGRAM([[
+        $curl_includes_string
+      ]],[[
+        if(0 != strncasecmp(0, 0, 0))
+          return 1;
+      ]])
+    ],[
+      AC_MSG_RESULT([yes])
+      tst_compi_strncasecmp="yes"
+    ],[
+      AC_MSG_RESULT([no])
+      tst_compi_strncasecmp="no"
+    ])
+  fi
+  #
+  if test "$tst_compi_strncasecmp" = "yes"; then
+    AC_MSG_CHECKING([if strncasecmp usage allowed])
+    if test "x$curl_disallow_strncasecmp" != "xyes"; then
+      AC_MSG_RESULT([yes])
+      tst_allow_strncasecmp="yes"
+    else
+      AC_MSG_RESULT([no])
+      tst_allow_strncasecmp="no"
+    fi
+  fi
+  #
+  AC_MSG_CHECKING([if strncasecmp might be used])
+  if test "$tst_links_strncasecmp" = "yes" &&
+     test "$tst_proto_strncasecmp" = "yes" &&
+     test "$tst_compi_strncasecmp" = "yes" &&
+     test "$tst_allow_strncasecmp" = "yes"; then
+    AC_MSG_RESULT([yes])
+    AC_DEFINE_UNQUOTED(HAVE_STRNCASECMP, 1,
+      [Define to 1 if you have the strncasecmp function.])
+    curl_cv_func_strncasecmp="yes"
+  else
+    AC_MSG_RESULT([no])
+    curl_cv_func_strncasecmp="no"
+  fi
+])
+
+
+dnl CURL_CHECK_FUNC_STRNCMPI
+dnl -------------------------------------------------
+dnl Verify if strncmpi is available, prototyped, and
+dnl can be compiled. If all of these are true, and
+dnl usage has not been previously disallowed with
+dnl shell variable curl_disallow_strncmpi, then
+dnl HAVE_STRNCMPI will be defined.
+
+AC_DEFUN([CURL_CHECK_FUNC_STRNCMPI], [
+  AC_REQUIRE([CURL_INCLUDES_STRING])dnl
+  #
+  tst_links_strncmpi="unknown"
+  tst_proto_strncmpi="unknown"
+  tst_compi_strncmpi="unknown"
+  tst_allow_strncmpi="unknown"
+  #
+  AC_MSG_CHECKING([if strncmpi can be linked])
+  AC_LINK_IFELSE([
+    AC_LANG_FUNC_LINK_TRY([strncmpi])
+  ],[
+    AC_MSG_RESULT([yes])
+    tst_links_strncmpi="yes"
+  ],[
+    AC_MSG_RESULT([no])
+    tst_links_strncmpi="no"
+  ])
+  #
+  if test "$tst_links_strncmpi" = "yes"; then
+    AC_MSG_CHECKING([if strncmpi is prototyped])
+    AC_EGREP_CPP([strncmpi],[
+      $curl_includes_string
+    ],[
+      AC_MSG_RESULT([yes])
+      tst_proto_strncmpi="yes"
+    ],[
+      AC_MSG_RESULT([no])
+      tst_proto_strncmpi="no"
+    ])
+  fi
+  #
+  if test "$tst_proto_strncmpi" = "yes"; then
+    AC_MSG_CHECKING([if strncmpi is compilable])
+    AC_COMPILE_IFELSE([
+      AC_LANG_PROGRAM([[
+        $curl_includes_string
+      ]],[[
+        if(0 != strncmpi(0, 0))
+          return 1;
+      ]])
+    ],[
+      AC_MSG_RESULT([yes])
+      tst_compi_strncmpi="yes"
+    ],[
+      AC_MSG_RESULT([no])
+      tst_compi_strncmpi="no"
+    ])
+  fi
+  #
+  if test "$tst_compi_strncmpi" = "yes"; then
+    AC_MSG_CHECKING([if strncmpi usage allowed])
+    if test "x$curl_disallow_strncmpi" != "xyes"; then
+      AC_MSG_RESULT([yes])
+      tst_allow_strncmpi="yes"
+    else
+      AC_MSG_RESULT([no])
+      tst_allow_strncmpi="no"
+    fi
+  fi
+  #
+  AC_MSG_CHECKING([if strncmpi might be used])
+  if test "$tst_links_strncmpi" = "yes" &&
+     test "$tst_proto_strncmpi" = "yes" &&
+     test "$tst_compi_strncmpi" = "yes" &&
+     test "$tst_allow_strncmpi" = "yes"; then
+    AC_MSG_RESULT([yes])
+    AC_DEFINE_UNQUOTED(HAVE_STRNCMPI, 1,
+      [Define to 1 if you have the strncmpi function.])
+    curl_cv_func_strncmpi="yes"
+  else
+    AC_MSG_RESULT([no])
+    curl_cv_func_strncmpi="no"
+  fi
+])
+
+
+dnl CURL_CHECK_FUNC_STRNICMP
+dnl -------------------------------------------------
+dnl Verify if strnicmp is available, prototyped, and
+dnl can be compiled. If all of these are true, and
+dnl usage has not been previously disallowed with
+dnl shell variable curl_disallow_strnicmp, then
+dnl HAVE_STRNICMP will be defined.
+
+AC_DEFUN([CURL_CHECK_FUNC_STRNICMP], [
+  AC_REQUIRE([CURL_INCLUDES_STRING])dnl
+  #
+  tst_links_strnicmp="unknown"
+  tst_proto_strnicmp="unknown"
+  tst_compi_strnicmp="unknown"
+  tst_allow_strnicmp="unknown"
+  #
+  AC_MSG_CHECKING([if strnicmp can be linked])
+  AC_LINK_IFELSE([
+    AC_LANG_FUNC_LINK_TRY([strnicmp])
+  ],[
+    AC_MSG_RESULT([yes])
+    tst_links_strnicmp="yes"
+  ],[
+    AC_MSG_RESULT([no])
+    tst_links_strnicmp="no"
+  ])
+  #
+  if test "$tst_links_strnicmp" = "yes"; then
+    AC_MSG_CHECKING([if strnicmp is prototyped])
+    AC_EGREP_CPP([strnicmp],[
+      $curl_includes_string
+    ],[
+      AC_MSG_RESULT([yes])
+      tst_proto_strnicmp="yes"
+    ],[
+      AC_MSG_RESULT([no])
+      tst_proto_strnicmp="no"
+    ])
+  fi
+  #
+  if test "$tst_proto_strnicmp" = "yes"; then
+    AC_MSG_CHECKING([if strnicmp is compilable])
+    AC_COMPILE_IFELSE([
+      AC_LANG_PROGRAM([[
+        $curl_includes_string
+      ]],[[
+        if(0 != strnicmp(0, 0))
+          return 1;
+      ]])
+    ],[
+      AC_MSG_RESULT([yes])
+      tst_compi_strnicmp="yes"
+    ],[
+      AC_MSG_RESULT([no])
+      tst_compi_strnicmp="no"
+    ])
+  fi
+  #
+  if test "$tst_compi_strnicmp" = "yes"; then
+    AC_MSG_CHECKING([if strnicmp usage allowed])
+    if test "x$curl_disallow_strnicmp" != "xyes"; then
+      AC_MSG_RESULT([yes])
+      tst_allow_strnicmp="yes"
+    else
+      AC_MSG_RESULT([no])
+      tst_allow_strnicmp="no"
+    fi
+  fi
+  #
+  AC_MSG_CHECKING([if strnicmp might be used])
+  if test "$tst_links_strnicmp" = "yes" &&
+     test "$tst_proto_strnicmp" = "yes" &&
+     test "$tst_compi_strnicmp" = "yes" &&
+     test "$tst_allow_strnicmp" = "yes"; then
+    AC_MSG_RESULT([yes])
+    AC_DEFINE_UNQUOTED(HAVE_STRNICMP, 1,
+      [Define to 1 if you have the strnicmp function.])
+    curl_cv_func_strnicmp="yes"
+  else
+    AC_MSG_RESULT([no])
+    curl_cv_func_strnicmp="no"
+  fi
+])
+
+
+dnl CURL_CHECK_FUNC_STRSTR
+dnl -------------------------------------------------
+dnl Verify if strstr is available, prototyped, and
+dnl can be compiled. If all of these are true, and
+dnl usage has not been previously disallowed with
+dnl shell variable curl_disallow_strstr, then
+dnl HAVE_STRSTR will be defined.
+
+AC_DEFUN([CURL_CHECK_FUNC_STRSTR], [
+  AC_REQUIRE([CURL_INCLUDES_STRING])dnl
+  #
+  tst_links_strstr="unknown"
+  tst_proto_strstr="unknown"
+  tst_compi_strstr="unknown"
+  tst_allow_strstr="unknown"
+  #
+  AC_MSG_CHECKING([if strstr can be linked])
+  AC_LINK_IFELSE([
+    AC_LANG_FUNC_LINK_TRY([strstr])
+  ],[
+    AC_MSG_RESULT([yes])
+    tst_links_strstr="yes"
+  ],[
+    AC_MSG_RESULT([no])
+    tst_links_strstr="no"
+  ])
+  #
+  if test "$tst_links_strstr" = "yes"; then
+    AC_MSG_CHECKING([if strstr is prototyped])
+    AC_EGREP_CPP([strstr],[
+      $curl_includes_string
+    ],[
+      AC_MSG_RESULT([yes])
+      tst_proto_strstr="yes"
+    ],[
+      AC_MSG_RESULT([no])
+      tst_proto_strstr="no"
+    ])
+  fi
+  #
+  if test "$tst_proto_strstr" = "yes"; then
+    AC_MSG_CHECKING([if strstr is compilable])
+    AC_COMPILE_IFELSE([
+      AC_LANG_PROGRAM([[
+        $curl_includes_string
+      ]],[[
+        if(0 != strstr(0, 0))
+          return 1;
+      ]])
+    ],[
+      AC_MSG_RESULT([yes])
+      tst_compi_strstr="yes"
+    ],[
+      AC_MSG_RESULT([no])
+      tst_compi_strstr="no"
+    ])
+  fi
+  #
+  if test "$tst_compi_strstr" = "yes"; then
+    AC_MSG_CHECKING([if strstr usage allowed])
+    if test "x$curl_disallow_strstr" != "xyes"; then
+      AC_MSG_RESULT([yes])
+      tst_allow_strstr="yes"
+    else
+      AC_MSG_RESULT([no])
+      tst_allow_strstr="no"
+    fi
+  fi
+  #
+  AC_MSG_CHECKING([if strstr might be used])
+  if test "$tst_links_strstr" = "yes" &&
+     test "$tst_proto_strstr" = "yes" &&
+     test "$tst_compi_strstr" = "yes" &&
+     test "$tst_allow_strstr" = "yes"; then
+    AC_MSG_RESULT([yes])
+    AC_DEFINE_UNQUOTED(HAVE_STRSTR, 1,
+      [Define to 1 if you have the strstr function.])
+    curl_cv_func_strstr="yes"
+  else
+    AC_MSG_RESULT([no])
+    curl_cv_func_strstr="no"
+  fi
+])
+
+
+dnl CURL_CHECK_FUNC_STRTOK_R
+dnl -------------------------------------------------
+dnl Verify if strtok_r is available, prototyped, and
+dnl can be compiled. If all of these are true, and
+dnl usage has not been previously disallowed with
+dnl shell variable curl_disallow_strtok_r, then
+dnl HAVE_STRTOK_R will be defined.
+
+AC_DEFUN([CURL_CHECK_FUNC_STRTOK_R], [
+  AC_REQUIRE([CURL_INCLUDES_STRING])dnl
+  #
+  tst_links_strtok_r="unknown"
+  tst_proto_strtok_r="unknown"
+  tst_compi_strtok_r="unknown"
+  tst_allow_strtok_r="unknown"
+  #
+  AC_MSG_CHECKING([if strtok_r can be linked])
+  AC_LINK_IFELSE([
+    AC_LANG_FUNC_LINK_TRY([strtok_r])
+  ],[
+    AC_MSG_RESULT([yes])
+    tst_links_strtok_r="yes"
+  ],[
+    AC_MSG_RESULT([no])
+    tst_links_strtok_r="no"
+  ])
+  #
+  if test "$tst_links_strtok_r" = "yes"; then
+    AC_MSG_CHECKING([if strtok_r is prototyped])
+    AC_EGREP_CPP([strtok_r],[
+      $curl_includes_string
+    ],[
+      AC_MSG_RESULT([yes])
+      tst_proto_strtok_r="yes"
+    ],[
+      AC_MSG_RESULT([no])
+      tst_proto_strtok_r="no"
+    ])
+  fi
+  #
+  if test "$tst_proto_strtok_r" = "yes"; then
+    AC_MSG_CHECKING([if strtok_r is compilable])
+    AC_COMPILE_IFELSE([
+      AC_LANG_PROGRAM([[
+        $curl_includes_string
+      ]],[[
+        if(0 != strtok_r(0, 0, 0))
+          return 1;
+      ]])
+    ],[
+      AC_MSG_RESULT([yes])
+      tst_compi_strtok_r="yes"
+    ],[
+      AC_MSG_RESULT([no])
+      tst_compi_strtok_r="no"
+    ])
+  fi
+  #
+  if test "$tst_compi_strtok_r" = "yes"; then
+    AC_MSG_CHECKING([if strtok_r usage allowed])
+    if test "x$curl_disallow_strtok_r" != "xyes"; then
+      AC_MSG_RESULT([yes])
+      tst_allow_strtok_r="yes"
+    else
+      AC_MSG_RESULT([no])
+      tst_allow_strtok_r="no"
+    fi
+  fi
+  #
+  AC_MSG_CHECKING([if strtok_r might be used])
+  if test "$tst_links_strtok_r" = "yes" &&
+     test "$tst_proto_strtok_r" = "yes" &&
+     test "$tst_compi_strtok_r" = "yes" &&
+     test "$tst_allow_strtok_r" = "yes"; then
+    AC_MSG_RESULT([yes])
+    AC_DEFINE_UNQUOTED(HAVE_STRTOK_R, 1,
+      [Define to 1 if you have the strtok_r function.])
+    curl_cv_func_strtok_r="yes"
+  else
+    AC_MSG_RESULT([no])
+    curl_cv_func_strtok_r="no"
+  fi
+])
+
+
+dnl CURL_CHECK_FUNC_STRTOLL
+dnl -------------------------------------------------
+dnl Verify if strtoll is available, prototyped, and
+dnl can be compiled. If all of these are true, and
+dnl usage has not been previously disallowed with
+dnl shell variable curl_disallow_strtoll, then
+dnl HAVE_STRTOLL will be defined.
+
+AC_DEFUN([CURL_CHECK_FUNC_STRTOLL], [
+  AC_REQUIRE([CURL_INCLUDES_STDLIB])dnl
+  #
+  tst_links_strtoll="unknown"
+  tst_proto_strtoll="unknown"
+  tst_compi_strtoll="unknown"
+  tst_allow_strtoll="unknown"
+  #
+  AC_MSG_CHECKING([if strtoll can be linked])
+  AC_LINK_IFELSE([
+    AC_LANG_FUNC_LINK_TRY([strtoll])
+  ],[
+    AC_MSG_RESULT([yes])
+    tst_links_strtoll="yes"
+  ],[
+    AC_MSG_RESULT([no])
+    tst_links_strtoll="no"
+  ])
+  #
+  if test "$tst_links_strtoll" = "yes"; then
+    AC_MSG_CHECKING([if strtoll is prototyped])
+    AC_EGREP_CPP([strtoll],[
+      $curl_includes_stdlib
+    ],[
+      AC_MSG_RESULT([yes])
+      tst_proto_strtoll="yes"
+    ],[
+      AC_MSG_RESULT([no])
+      tst_proto_strtoll="no"
+    ])
+  fi
+  #
+  if test "$tst_proto_strtoll" = "yes"; then
+    AC_MSG_CHECKING([if strtoll is compilable])
+    AC_COMPILE_IFELSE([
+      AC_LANG_PROGRAM([[
+        $curl_includes_stdlib
+      ]],[[
+        if(0 != strtoll(0, 0, 0))
+          return 1;
+      ]])
+    ],[
+      AC_MSG_RESULT([yes])
+      tst_compi_strtoll="yes"
+    ],[
+      AC_MSG_RESULT([no])
+      tst_compi_strtoll="no"
+    ])
+  fi
+  #
+  if test "$tst_compi_strtoll" = "yes"; then
+    AC_MSG_CHECKING([if strtoll usage allowed])
+    if test "x$curl_disallow_strtoll" != "xyes"; then
+      AC_MSG_RESULT([yes])
+      tst_allow_strtoll="yes"
+    else
+      AC_MSG_RESULT([no])
+      tst_allow_strtoll="no"
+    fi
+  fi
+  #
+  AC_MSG_CHECKING([if strtoll might be used])
+  if test "$tst_links_strtoll" = "yes" &&
+     test "$tst_proto_strtoll" = "yes" &&
+     test "$tst_compi_strtoll" = "yes" &&
+     test "$tst_allow_strtoll" = "yes"; then
+    AC_MSG_RESULT([yes])
+    AC_DEFINE_UNQUOTED(HAVE_STRTOLL, 1,
+      [Define to 1 if you have the strtoll function.])
+    curl_cv_func_strtoll="yes"
+  else
+    AC_MSG_RESULT([no])
+    curl_cv_func_strtoll="no"
+  fi
+])
+
+
+dnl CURL_CHECK_FUNC_WRITEV
+dnl -------------------------------------------------
+dnl Verify if writev is available, prototyped, and
+dnl can be compiled. If all of these are true, and
+dnl usage has not been previously disallowed with
+dnl shell variable curl_disallow_writev, then
+dnl HAVE_WRITEV will be defined.
+
+AC_DEFUN([CURL_CHECK_FUNC_WRITEV], [
+  AC_REQUIRE([CURL_INCLUDES_SYS_UIO])dnl
+  #
+  tst_links_writev="unknown"
+  tst_proto_writev="unknown"
+  tst_compi_writev="unknown"
+  tst_allow_writev="unknown"
+  #
+  AC_MSG_CHECKING([if writev can be linked])
+  AC_LINK_IFELSE([
+    AC_LANG_FUNC_LINK_TRY([writev])
+  ],[
+    AC_MSG_RESULT([yes])
+    tst_links_writev="yes"
+  ],[
+    AC_MSG_RESULT([no])
+    tst_links_writev="no"
+  ])
+  #
+  if test "$tst_links_writev" = "yes"; then
+    AC_MSG_CHECKING([if writev is prototyped])
+    AC_EGREP_CPP([writev],[
+      $curl_includes_sys_uio
+    ],[
+      AC_MSG_RESULT([yes])
+      tst_proto_writev="yes"
+    ],[
+      AC_MSG_RESULT([no])
+      tst_proto_writev="no"
+    ])
+  fi
+  #
+  if test "$tst_proto_writev" = "yes"; then
+    AC_MSG_CHECKING([if writev is compilable])
+    AC_COMPILE_IFELSE([
+      AC_LANG_PROGRAM([[
+        $curl_includes_sys_uio
+      ]],[[
+        if(0 != writev(0, 0, 0))
+          return 1;
+      ]])
+    ],[
+      AC_MSG_RESULT([yes])
+      tst_compi_writev="yes"
+    ],[
+      AC_MSG_RESULT([no])
+      tst_compi_writev="no"
+    ])
+  fi
+  #
+  if test "$tst_compi_writev" = "yes"; then
+    AC_MSG_CHECKING([if writev usage allowed])
+    if test "x$curl_disallow_writev" != "xyes"; then
+      AC_MSG_RESULT([yes])
+      tst_allow_writev="yes"
+    else
+      AC_MSG_RESULT([no])
+      tst_allow_writev="no"
+    fi
+  fi
+  #
+  AC_MSG_CHECKING([if writev might be used])
+  if test "$tst_links_writev" = "yes" &&
+     test "$tst_proto_writev" = "yes" &&
+     test "$tst_compi_writev" = "yes" &&
+     test "$tst_allow_writev" = "yes"; then
+    AC_MSG_RESULT([yes])
+    AC_DEFINE_UNQUOTED(HAVE_WRITEV, 1,
+      [Define to 1 if you have the writev function.])
+    curl_cv_func_writev="yes"
+  else
+    AC_MSG_RESULT([no])
+    curl_cv_func_writev="no"
+  fi
+])