1 /* $OpenBSD: getusershell.c,v 1.8 2005/08/08 08:05:34 espie Exp $ */
2 /*
3 * Copyright (c) 1985, 1993
4 * The Regents of the University of California. All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
14 * 3. Neither the name of the University nor the names of its contributors
15 * may be used to endorse or promote products derived from this software
16 * without specific prior written permission.
17 *
18 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
19 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
22 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
23 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
24 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
25 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
26 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
27 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
28 * SUCH DAMAGE.
29 */
30
31 #include <sys/param.h>
32 #include <sys/file.h>
33 #include <sys/stat.h>
34 #include <stdio.h>
35 #include <ctype.h>
36 #include <stdlib.h>
37 #include <unistd.h>
38 #include <paths.h>
39
40 __RCSID("$MirOS: src/lib/libc/gen/getusershell.c,v 1.5 2006/06/02 02:29:49 tg Exp $");
41
42 /*
43 * Local shells should NOT be added here. They should be added in
44 * /etc/shells.
45 */
46
47 static char *okshells[] = { (char *)_PATH_BSHELL, (char *)"/bin/mksh", NULL };
48 static char **curshell, **shells, *strings;
49 static char **initshells(void);
50
51 /*
52 * Get a list of shells from _PATH_SHELLS, if it exists.
53 */
54 char *
getusershell(void)55 getusershell(void)
56 {
57 char *ret;
58
59 if (curshell == NULL)
60 curshell = initshells();
61 ret = *curshell;
62 if (ret != NULL)
63 curshell++;
64 return (ret);
65 }
66
67 void
endusershell(void)68 endusershell(void)
69 {
70
71 if (shells != NULL)
72 free(shells);
73 shells = NULL;
74 if (strings != NULL)
75 free(strings);
76 strings = NULL;
77 curshell = NULL;
78 }
79
80 void
setusershell(void)81 setusershell(void)
82 {
83
84 curshell = initshells();
85 }
86
87 static char **
initshells(void)88 initshells(void)
89 {
90 char **sp, *cp;
91 FILE *fp;
92 struct stat statb;
93
94 if (shells != NULL)
95 free(shells);
96 shells = NULL;
97 if (strings != NULL)
98 free(strings);
99 strings = NULL;
100 if ((fp = fopen(_PATH_SHELLS, "r")) == NULL)
101 return (okshells);
102 if (fstat(fileno(fp), &statb) == -1) {
103 (void)fclose(fp);
104 return (okshells);
105 }
106 if ((strings = malloc((u_int)statb.st_size)) == NULL) {
107 (void)fclose(fp);
108 return (okshells);
109 }
110 shells = calloc((unsigned)statb.st_size / 3, sizeof (char *));
111 if (shells == NULL) {
112 (void)fclose(fp);
113 free(strings);
114 strings = NULL;
115 return (okshells);
116 }
117 sp = shells;
118 cp = strings;
119 while (fgets(cp, MAXPATHLEN + 1, fp) != NULL) {
120 while (*cp != '#' && *cp != '/' && *cp != '\0')
121 cp++;
122 if (*cp == '#' || *cp == '\0')
123 continue;
124 *sp++ = cp;
125 while (!isspace(*cp) && *cp != '#' && *cp != '\0')
126 cp++;
127 *cp++ = '\0';
128 }
129 *sp = NULL;
130 (void)fclose(fp);
131 return (shells);
132 }
133