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[] = "@(#)getusershell.c 5.7 (Berkeley) 2/23/91"; 36 #endif /* LIBC_SCCS and not lint */ 37 38 #include <sys/param.h> 39 #include <sys/file.h> 40 #include <sys/stat.h> 41 #include <ctype.h> 42 #include <stdio.h> 43 #include <stdlib.h> 44 #include <unistd.h> 45 46 #define SHELLS "/etc/shells" 47 48 /* 49 * Do not add local shells here. They should be added in /etc/shells 50 */ 51 static char *okshells[] = 52 { "/bin/sh", "/bin/csh", 0 }; 53 54 static char **shells, *strings; 55 static char **curshell = NULL; 56 extern char **initshells(); 57 58 /* 59 * Get a list of shells from SHELLS, if it exists. 60 */ 61 char * 62 getusershell() 63 { 64 char *ret; 65 66 if (curshell == NULL) 67 curshell = initshells(); 68 ret = *curshell; 69 if (ret != NULL) 70 curshell++; 71 return (ret); 72 } 73 74 void 75 endusershell() 76 { 77 78 if (shells != NULL) 79 free((char *)shells); 80 shells = NULL; 81 if (strings != NULL) 82 free(strings); 83 strings = NULL; 84 curshell = NULL; 85 } 86 87 void 88 setusershell() 89 { 90 91 curshell = initshells(); 92 } 93 94 static char ** 95 initshells() 96 { 97 register char **sp, *cp; 98 register FILE *fp; 99 struct stat statb; 100 101 if (shells != NULL) 102 free((char *)shells); 103 shells = NULL; 104 if (strings != NULL) 105 free(strings); 106 strings = NULL; 107 if ((fp = fopen(SHELLS, "r")) == (FILE *)0) 108 return(okshells); 109 if (fstat(fileno(fp), &statb) == -1) { 110 (void)fclose(fp); 111 return(okshells); 112 } 113 if ((strings = malloc((unsigned)statb.st_size)) == NULL) { 114 (void)fclose(fp); 115 return(okshells); 116 } 117 shells = (char **)calloc((unsigned)statb.st_size / 3, sizeof (char *)); 118 if (shells == NULL) { 119 (void)fclose(fp); 120 free(strings); 121 strings = NULL; 122 return(okshells); 123 } 124 sp = shells; 125 cp = strings; 126 while (fgets(cp, MAXPATHLEN + 1, fp) != NULL) { 127 while (*cp != '#' && *cp != '/' && *cp != '\0') 128 cp++; 129 if (*cp == '#' || *cp == '\0') 130 continue; 131 *sp++ = cp; 132 while (!isspace(*cp) && *cp != '#' && *cp != '\0') 133 cp++; 134 *cp++ = '\0'; 135 } 136 *sp = (char *)0; 137 (void)fclose(fp); 138 return (shells); 139 } 140