1 /* 2 * Copyright (c) 1985 Regents of the University of California. 3 * 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. All advertising materials mentioning features or use of this software 14 * must display the following acknowledgement: 15 * This product includes software developed by the University of 16 * California, Berkeley and its contributors. 17 * 4. Neither the name of the University nor the names of its contributors 18 * may be used to endorse or promote products derived from this software 19 * without specific prior written permission. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 24 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31 * SUCH DAMAGE. 32 */ 33 34 #if defined(LIBC_SCCS) && !defined(lint) 35 /*static char *sccsid = "from: @(#)getusershell.c 5.7 (Berkeley) 2/23/91";*/ 36 static char *rcsid = "$Id: getusershell.c,v 1.4 1993/08/26 00:44:45 jtc Exp $"; 37 #endif /* LIBC_SCCS and not lint */ 38 39 #include <sys/param.h> 40 #include <sys/file.h> 41 #include <sys/stat.h> 42 #include <ctype.h> 43 #include <stdio.h> 44 #include <stdlib.h> 45 #include <unistd.h> 46 47 #define SHELLS "/etc/shells" 48 49 /* 50 * Do not add local shells here. They should be added in /etc/shells 51 */ 52 static char *okshells[] = 53 { "/bin/sh", "/bin/csh", 0 }; 54 55 static char **shells, *strings; 56 static char **curshell = NULL; 57 static char **initshells(); 58 59 /* 60 * Get a list of shells from SHELLS, if it exists. 61 */ 62 char * 63 getusershell() 64 { 65 char *ret; 66 67 if (curshell == NULL) 68 curshell = initshells(); 69 ret = *curshell; 70 if (ret != NULL) 71 curshell++; 72 return (ret); 73 } 74 75 void 76 endusershell() 77 { 78 79 if (shells != NULL) 80 free((char *)shells); 81 shells = NULL; 82 if (strings != NULL) 83 free(strings); 84 strings = NULL; 85 curshell = NULL; 86 } 87 88 void 89 setusershell() 90 { 91 92 curshell = initshells(); 93 } 94 95 static char ** 96 initshells() 97 { 98 register char **sp, *cp; 99 register FILE *fp; 100 struct stat statb; 101 102 if (shells != NULL) 103 free((char *)shells); 104 shells = NULL; 105 if (strings != NULL) 106 free(strings); 107 strings = NULL; 108 if ((fp = fopen(SHELLS, "r")) == (FILE *)0) 109 return(okshells); 110 if (fstat(fileno(fp), &statb) == -1) { 111 (void)fclose(fp); 112 return(okshells); 113 } 114 if ((strings = malloc((unsigned)statb.st_size)) == NULL) { 115 (void)fclose(fp); 116 return(okshells); 117 } 118 shells = (char **)calloc((unsigned)statb.st_size / 3, sizeof (char *)); 119 if (shells == NULL) { 120 (void)fclose(fp); 121 free(strings); 122 strings = NULL; 123 return(okshells); 124 } 125 sp = shells; 126 cp = strings; 127 while (fgets(cp, MAXPATHLEN + 1, fp) != NULL) { 128 while (*cp != '#' && *cp != '/' && *cp != '\0') 129 cp++; 130 if (*cp == '#' || *cp == '\0') 131 continue; 132 *sp++ = cp; 133 while (!isspace(*cp) && *cp != '#' && *cp != '\0') 134 cp++; 135 *cp++ = '\0'; 136 } 137 *sp = (char *)0; 138 (void)fclose(fp); 139 return (shells); 140 } 141