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 * 3. 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 rcsid[] = "$OpenBSD: getusershell.c,v 1.5 2004/05/18 02:05:52 jfb Exp $"; 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 <ctype.h> 39 #include <stdlib.h> 40 #include <unistd.h> 41 #include <paths.h> 42 43 /* 44 * Local shells should NOT be added here. They should be added in 45 * /etc/shells. 46 */ 47 48 static char *okshells[] = { _PATH_BSHELL, _PATH_CSHELL, NULL }; 49 static char **curshell, **shells, *strings; 50 static char **initshells(void); 51 52 /* 53 * Get a list of shells from _PATH_SHELLS, if it exists. 54 */ 55 char * 56 getusershell(void) 57 { 58 char *ret; 59 60 if (curshell == NULL) 61 curshell = initshells(); 62 ret = *curshell; 63 if (ret != NULL) 64 curshell++; 65 return (ret); 66 } 67 68 void 69 endusershell(void) 70 { 71 72 if (shells != NULL) 73 free(shells); 74 shells = NULL; 75 if (strings != NULL) 76 free(strings); 77 strings = NULL; 78 curshell = NULL; 79 } 80 81 void 82 setusershell(void) 83 { 84 85 curshell = initshells(); 86 } 87 88 static char ** 89 initshells(void) 90 { 91 register char **sp, *cp; 92 register FILE *fp; 93 struct stat statb; 94 95 if (shells != NULL) 96 free(shells); 97 shells = NULL; 98 if (strings != NULL) 99 free(strings); 100 strings = NULL; 101 if ((fp = fopen(_PATH_SHELLS, "r")) == NULL) 102 return (okshells); 103 if (fstat(fileno(fp), &statb) == -1) { 104 (void)fclose(fp); 105 return (okshells); 106 } 107 if ((strings = malloc((u_int)statb.st_size)) == NULL) { 108 (void)fclose(fp); 109 return (okshells); 110 } 111 shells = calloc((unsigned)statb.st_size / 3, sizeof (char *)); 112 if (shells == NULL) { 113 (void)fclose(fp); 114 free(strings); 115 strings = NULL; 116 return (okshells); 117 } 118 sp = shells; 119 cp = strings; 120 while (fgets(cp, MAXPATHLEN + 1, fp) != NULL) { 121 while (*cp != '#' && *cp != '/' && *cp != '\0') 122 cp++; 123 if (*cp == '#' || *cp == '\0') 124 continue; 125 *sp++ = cp; 126 while (!isspace(*cp) && *cp != '#' && *cp != '\0') 127 cp++; 128 *cp++ = '\0'; 129 } 130 *sp = NULL; 131 (void)fclose(fp); 132 return (shells); 133 } 134