1 /* $NetBSD: getusershell.c,v 1.12 1998/11/13 15:49:29 christos Exp $ */ 2 3 /* 4 * Copyright (c) 1985, 1993 5 * The Regents of the University of California. All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. All advertising materials mentioning features or use of this software 16 * must display the following acknowledgement: 17 * This product includes software developed by the University of 18 * California, Berkeley and its contributors. 19 * 4. Neither the name of the University nor the names of its contributors 20 * may be used to endorse or promote products derived from this software 21 * without specific prior written permission. 22 * 23 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 26 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 33 * SUCH DAMAGE. 34 */ 35 36 #include <sys/cdefs.h> 37 #if defined(LIBC_SCCS) && !defined(lint) 38 #if 0 39 static char sccsid[] = "@(#)getusershell.c 8.1 (Berkeley) 6/4/93"; 40 #else 41 __RCSID("$NetBSD: getusershell.c,v 1.12 1998/11/13 15:49:29 christos Exp $"); 42 #endif 43 #endif /* LIBC_SCCS and not lint */ 44 45 #include "namespace.h" 46 #include <sys/param.h> 47 #include <sys/file.h> 48 #include <sys/stat.h> 49 #include <stdio.h> 50 #include <ctype.h> 51 #include <stdlib.h> 52 #include <unistd.h> 53 #include <paths.h> 54 55 #ifdef __weak_alias 56 __weak_alias(endusershell,_endusershell); 57 __weak_alias(getusershell,_getusershell); 58 __weak_alias(setusershell,_setusershell); 59 #endif 60 61 /* 62 * Local shells should NOT be added here. They should be added in 63 * /etc/shells. 64 */ 65 66 static const char *const okshells[] = { _PATH_BSHELL, _PATH_CSHELL, NULL }; 67 static const char *const *curshell, **shells; 68 static char *strings; 69 static const char *const *initshells __P((void)); 70 71 /* 72 * Get a list of shells from _PATH_SHELLS, if it exists. 73 */ 74 __aconst char * 75 getusershell() 76 { 77 __aconst char *ret; 78 79 if (curshell == NULL) 80 curshell = initshells(); 81 82 /* LINTED (auditing puproses only */ 83 ret = (__aconst char *)*curshell; 84 85 if (ret != NULL) 86 curshell++; 87 return (ret); 88 } 89 90 void 91 endusershell() 92 { 93 94 if (shells != NULL) 95 free(shells); 96 shells = NULL; 97 if (strings != NULL) 98 free(strings); 99 strings = NULL; 100 curshell = NULL; 101 } 102 103 void 104 setusershell() 105 { 106 107 curshell = initshells(); 108 } 109 110 static const char *const * 111 initshells() 112 { 113 const char **sp; 114 char *cp; 115 FILE *fp; 116 struct stat statb; 117 118 if (shells != NULL) 119 free(shells); 120 shells = NULL; 121 if (strings != NULL) 122 free(strings); 123 strings = NULL; 124 if ((fp = fopen(_PATH_SHELLS, "r")) == NULL) 125 return (okshells); 126 if (fstat(fileno(fp), &statb) == -1) { 127 (void)fclose(fp); 128 return (okshells); 129 } 130 if ((cp = malloc((u_int)statb.st_size)) == NULL) { 131 (void)fclose(fp); 132 return (okshells); 133 } 134 sp = calloc((unsigned)statb.st_size / 3, sizeof (char *)); 135 if (sp == NULL) { 136 (void)fclose(fp); 137 free(cp); 138 strings = NULL; 139 return (okshells); 140 } 141 shells = sp; 142 strings = cp; 143 while (fgets(cp, MAXPATHLEN + 1, fp) != NULL) { 144 while (*cp != '#' && *cp != '/' && *cp != '\0') 145 cp++; 146 if (*cp == '#' || *cp == '\0') 147 continue; 148 *sp++ = cp; 149 while (!isspace(*cp) && *cp != '#' && *cp != '\0') 150 cp++; 151 *cp++ = '\0'; 152 } 153 *sp = NULL; 154 (void)fclose(fp); 155 return (shells); 156 } 157