diff --git a/ap/libc/glibc/glibc-2.23/misc/getusershell.c b/ap/libc/glibc/glibc-2.23/misc/getusershell.c
new file mode 100644
index 0000000..fc2c43b
--- /dev/null
+++ b/ap/libc/glibc/glibc-2.23/misc/getusershell.c
@@ -0,0 +1,143 @@
+/*
+ * Copyright (c) 1985, 1993
+ *	The Regents of the University of California.  All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 4. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#if defined(LIBC_SCCS) && !defined(lint)
+static char sccsid[] = "@(#)getusershell.c	8.1 (Berkeley) 6/4/93";
+#endif /* LIBC_SCCS and not lint */
+
+#include <sys/param.h>
+#include <sys/file.h>
+#include <sys/stat.h>
+#include <stdio.h>
+#include <stdio_ext.h>
+#include <ctype.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <paths.h>
+
+/*
+ * Local shells should NOT be added here.  They should be added in
+ * /etc/shells.
+ */
+
+/* NB: we do not initialize okshells here.  The initialization needs
+   relocations.  These interfaces are used so rarely that this is not
+   justified.  Instead explicitly initialize the array when it is
+   used.  */
+#if 0
+static const char *const okshells[] = { _PATH_BSHELL, _PATH_CSHELL, NULL };
+#else
+static const char *okshells[3];
+#endif
+static char **curshell, **shells, *strings;
+static char **initshells (void) __THROW;
+
+/*
+ * Get a list of shells from _PATH_SHELLS, if it exists.
+ */
+char *
+getusershell (void)
+{
+	char *ret;
+
+	if (curshell == NULL)
+		curshell = initshells();
+	ret = *curshell;
+	if (ret != NULL)
+		curshell++;
+	return (ret);
+}
+
+void
+endusershell (void)
+{
+
+	free(shells);
+	shells = NULL;
+	free(strings);
+	strings = NULL;
+	curshell = NULL;
+}
+
+void
+setusershell (void)
+{
+
+	curshell = initshells();
+}
+
+static char **
+initshells (void)
+{
+	char **sp, *cp;
+	FILE *fp;
+	struct stat64 statb;
+	size_t flen;
+
+	free(shells);
+	shells = NULL;
+	free(strings);
+	strings = NULL;
+	if ((fp = fopen(_PATH_SHELLS, "rce")) == NULL)
+		goto init_okshells_noclose;
+	if (fstat64(fileno(fp), &statb) == -1) {
+	init_okshells:
+		(void)fclose(fp);
+	init_okshells_noclose:
+		okshells[0] = _PATH_BSHELL;
+		okshells[1] = _PATH_CSHELL;
+		return (char **) okshells;
+	}
+	if (statb.st_size > ~(size_t)0 / sizeof (char *) * 3)
+		goto init_okshells;
+	flen = statb.st_size + 3;
+	if ((strings = malloc(flen)) == NULL)
+		goto init_okshells;
+	shells = malloc(statb.st_size / 3 * sizeof (char *));
+	if (shells == NULL) {
+		free(strings);
+		strings = NULL;
+		goto init_okshells;
+	}
+	sp = shells;
+	cp = strings;
+	while (fgets_unlocked(cp, flen - (cp - strings), fp) != NULL) {
+		while (*cp != '#' && *cp != '/' && *cp != '\0')
+			cp++;
+		if (*cp == '#' || *cp == '\0' || cp[1] == '\0')
+			continue;
+		*sp++ = cp;
+		while (!isspace(*cp) && *cp != '#' && *cp != '\0')
+			cp++;
+		*cp++ = '\0';
+	}
+	*sp = NULL;
+	(void)fclose(fp);
+	return (shells);
+}