| lh | 9ed821d | 2023-04-07 01:36:19 -0700 | [diff] [blame] | 1 | /* |
| 2 | * Copyright (c) 1985, 1993 |
| 3 | * The Regents of the University of California. All rights reserved. |
| 4 | * |
| 5 | * Redistribution and use in source and binary forms, with or without |
| 6 | * modification, are permitted provided that the following conditions |
| 7 | * are met: |
| 8 | * 1. Redistributions of source code must retain the above copyright |
| 9 | * notice, this list of conditions and the following disclaimer. |
| 10 | * 2. Redistributions in binary form must reproduce the above copyright |
| 11 | * notice, this list of conditions and the following disclaimer in the |
| 12 | * documentation and/or other materials provided with the distribution. |
| 13 | * 4. Neither the name of the University nor the names of its contributors |
| 14 | * may be used to endorse or promote products derived from this software |
| 15 | * without specific prior written permission. |
| 16 | * |
| 17 | * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND |
| 18 | * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
| 19 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
| 20 | * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE |
| 21 | * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL |
| 22 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS |
| 23 | * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) |
| 24 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT |
| 25 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY |
| 26 | * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF |
| 27 | * SUCH DAMAGE. |
| 28 | */ |
| 29 | |
| 30 | #if defined(LIBC_SCCS) && !defined(lint) |
| 31 | static char sccsid[] = "@(#)getusershell.c 8.1 (Berkeley) 6/4/93"; |
| 32 | #endif /* LIBC_SCCS and not lint */ |
| 33 | |
| 34 | #include <sys/param.h> |
| 35 | #include <sys/file.h> |
| 36 | #include <sys/stat.h> |
| 37 | #include <stdio.h> |
| 38 | #include <stdio_ext.h> |
| 39 | #include <ctype.h> |
| 40 | #include <stdlib.h> |
| 41 | #include <unistd.h> |
| 42 | #include <paths.h> |
| 43 | |
| 44 | /* |
| 45 | * Local shells should NOT be added here. They should be added in |
| 46 | * /etc/shells. |
| 47 | */ |
| 48 | |
| 49 | /* NB: we do not initialize okshells here. The initialization needs |
| 50 | relocations. These interfaces are used so rarely that this is not |
| 51 | justified. Instead explicitly initialize the array when it is |
| 52 | used. */ |
| 53 | #if 0 |
| 54 | static const char *const okshells[] = { _PATH_BSHELL, _PATH_CSHELL, NULL }; |
| 55 | #else |
| 56 | static const char *okshells[3]; |
| 57 | #endif |
| 58 | static char **curshell, **shells, *strings; |
| 59 | static char **initshells (void) __THROW; |
| 60 | |
| 61 | /* |
| 62 | * Get a list of shells from _PATH_SHELLS, if it exists. |
| 63 | */ |
| 64 | char * |
| 65 | getusershell (void) |
| 66 | { |
| 67 | char *ret; |
| 68 | |
| 69 | if (curshell == NULL) |
| 70 | curshell = initshells(); |
| 71 | ret = *curshell; |
| 72 | if (ret != NULL) |
| 73 | curshell++; |
| 74 | return (ret); |
| 75 | } |
| 76 | |
| 77 | void |
| 78 | endusershell (void) |
| 79 | { |
| 80 | |
| 81 | free(shells); |
| 82 | shells = NULL; |
| 83 | free(strings); |
| 84 | strings = NULL; |
| 85 | curshell = NULL; |
| 86 | } |
| 87 | |
| 88 | void |
| 89 | setusershell (void) |
| 90 | { |
| 91 | |
| 92 | curshell = initshells(); |
| 93 | } |
| 94 | |
| 95 | static char ** |
| 96 | initshells (void) |
| 97 | { |
| 98 | char **sp, *cp; |
| 99 | FILE *fp; |
| 100 | struct stat64 statb; |
| 101 | size_t flen; |
| 102 | |
| 103 | free(shells); |
| 104 | shells = NULL; |
| 105 | free(strings); |
| 106 | strings = NULL; |
| 107 | if ((fp = fopen(_PATH_SHELLS, "rce")) == NULL) |
| 108 | goto init_okshells_noclose; |
| 109 | if (fstat64(fileno(fp), &statb) == -1) { |
| 110 | init_okshells: |
| 111 | (void)fclose(fp); |
| 112 | init_okshells_noclose: |
| 113 | okshells[0] = _PATH_BSHELL; |
| 114 | okshells[1] = _PATH_CSHELL; |
| 115 | return (char **) okshells; |
| 116 | } |
| 117 | if (statb.st_size > ~(size_t)0 / sizeof (char *) * 3) |
| 118 | goto init_okshells; |
| 119 | flen = statb.st_size + 3; |
| 120 | if ((strings = malloc(flen)) == NULL) |
| 121 | goto init_okshells; |
| 122 | shells = malloc(statb.st_size / 3 * sizeof (char *)); |
| 123 | if (shells == NULL) { |
| 124 | free(strings); |
| 125 | strings = NULL; |
| 126 | goto init_okshells; |
| 127 | } |
| 128 | sp = shells; |
| 129 | cp = strings; |
| 130 | while (fgets_unlocked(cp, flen - (cp - strings), fp) != NULL) { |
| 131 | while (*cp != '#' && *cp != '/' && *cp != '\0') |
| 132 | cp++; |
| 133 | if (*cp == '#' || *cp == '\0' || cp[1] == '\0') |
| 134 | continue; |
| 135 | *sp++ = cp; |
| 136 | while (!isspace(*cp) && *cp != '#' && *cp != '\0') |
| 137 | cp++; |
| 138 | *cp++ = '\0'; |
| 139 | } |
| 140 | *sp = NULL; |
| 141 | (void)fclose(fp); |
| 142 | return (shells); |
| 143 | } |