1 /* $OpenBSD: which.c,v 1.14 2007/08/14 17:41:10 sobrado Exp $ */ 2 3 /* 4 * Copyright (c) 1997 Todd C. Miller <Todd.Miller@courtesan.com> 5 * 6 * Permission to use, copy, modify, and distribute this software for any 7 * purpose with or without fee is hereby granted, provided that the above 8 * copyright notice and this permission notice appear in all copies. 9 * 10 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES 11 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF 12 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR 13 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES 14 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN 15 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF 16 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. 17 */ 18 19 #ifndef lint 20 static const char rcsid[] = "$OpenBSD: which.c,v 1.14 2007/08/14 17:41:10 sobrado Exp $"; 21 #endif /* not lint */ 22 23 #include <sys/param.h> 24 #include <sys/stat.h> 25 #include <sys/sysctl.h> 26 27 #include <err.h> 28 #include <errno.h> 29 #include <locale.h> 30 #include <stdio.h> 31 #include <stdlib.h> 32 #include <string.h> 33 #include <unistd.h> 34 35 #define PROG_WHICH 1 36 #define PROG_WHEREIS 2 37 38 extern char *__progname; 39 40 int findprog(char *, char *, int, int); 41 __dead void usage(void); 42 43 /* 44 * which(1) -- find an executable(s) in the user's path 45 * whereis(1) -- find an executable(s) in the default user path 46 * 47 * Return values: 48 * 0 - all executables found 49 * 1 - some found, some not 50 * 2 - none found 51 */ 52 53 int 54 main(int argc, char *argv[]) 55 { 56 char *path; 57 size_t n; 58 int ch, allmatches = 0, notfound = 0, progmode = PROG_WHICH; 59 60 (void)setlocale(LC_ALL, ""); 61 62 if (argc == 1) 63 usage(); 64 65 /* Don't accept command args but check since old whereis(1) used to */ 66 while ((ch = getopt(argc, argv, "a")) != -1) { 67 switch (ch) { 68 case 'a': 69 allmatches = 1; 70 break; 71 default: 72 usage(); 73 } 74 } 75 76 /* 77 * which(1) uses user's $PATH. 78 * whereis(1) uses user.cs_path from sysctl(3). 79 */ 80 if (strcmp(__progname, "whereis") == 0) { 81 int mib[2]; 82 83 progmode = PROG_WHEREIS; 84 mib[0] = CTL_USER; 85 mib[1] = USER_CS_PATH; 86 if (sysctl(mib, 2, NULL, &n, NULL, 0) == -1) 87 err(1, "unable to get length of user.cs_path"); 88 if (n == 0) 89 errx(1, "user.cs_path was zero length!"); 90 if ((path = (char *)malloc(n)) == NULL) 91 errx(1, "can't allocate memory."); 92 if (sysctl(mib, 2, path, &n, NULL, 0) == -1) 93 err(1, "unable to get user.cs_path"); 94 } else { 95 if ((path = getenv("PATH")) == NULL) 96 err(1, "can't get $PATH from environment"); 97 } 98 99 /* To make access(2) do what we want */ 100 if (setgid(getegid())) 101 err(1, "Can't set gid to %u", getegid()); 102 if (setuid(geteuid())) 103 err(1, "Can't set uid to %u", geteuid()); 104 105 for (n = optind; n < argc; n++) 106 if (findprog(argv[n], path, progmode, allmatches) == 0) 107 notfound++; 108 109 exit((notfound == 0) ? 0 : ((notfound == argc - 1) ? 2 : 1)); 110 } 111 112 int 113 findprog(char *prog, char *path, int progmode, int allmatches) 114 { 115 char *p, filename[MAXPATHLEN]; 116 int proglen, plen, rval = 0; 117 struct stat sbuf; 118 char *pathcpy; 119 120 /* Special case if prog contains '/' */ 121 if (strchr(prog, '/')) { 122 if ((stat(prog, &sbuf) == 0) && S_ISREG(sbuf.st_mode) && 123 access(prog, X_OK) == 0) { 124 (void)puts(prog); 125 return (1); 126 } else { 127 (void)printf("%s: Command not found.\n", prog); 128 return (0); 129 } 130 } 131 132 if ((path = strdup(path)) == NULL) 133 errx(1, "Can't allocate memory."); 134 pathcpy = path; 135 136 proglen = strlen(prog); 137 while ((p = strsep(&pathcpy, ":")) != NULL) { 138 if (*p == '\0') 139 p = "."; 140 141 plen = strlen(p); 142 while (p[plen-1] == '/') 143 p[--plen] = '\0'; /* strip trailing '/' */ 144 145 if (plen + 1 + proglen >= sizeof(filename)) { 146 warnx("%s/%s: %s", p, prog, strerror(ENAMETOOLONG)); 147 free(path); 148 return (0); 149 } 150 151 snprintf(filename, sizeof(filename), "%s/%s", p, prog); 152 if ((stat(filename, &sbuf) == 0) && S_ISREG(sbuf.st_mode) && 153 access(filename, X_OK) == 0) { 154 (void)puts(filename); 155 rval = 1; 156 if (!allmatches) { 157 free(path); 158 return (rval); 159 } 160 } 161 } 162 (void)free(path); 163 164 /* whereis(1) is silent on failure. */ 165 if (!rval && progmode != PROG_WHEREIS) 166 (void)printf("%s: Command not found.\n", prog); 167 return (rval); 168 } 169 170 __dead void 171 usage(void) 172 { 173 (void)fprintf(stderr, "usage: %s [-a] name ...\n", __progname); 174 exit(1); 175 } 176