1 /* $OpenBSD: which.c,v 1.19 2014/05/20 01:25:23 guenther 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 #include <sys/param.h> 20 #include <sys/stat.h> 21 #include <sys/sysctl.h> 22 23 #include <err.h> 24 #include <errno.h> 25 #include <locale.h> 26 #include <paths.h> 27 #include <stdio.h> 28 #include <stdlib.h> 29 #include <string.h> 30 #include <unistd.h> 31 32 #define PROG_WHICH 1 33 #define PROG_WHEREIS 2 34 35 extern char *__progname; 36 37 int findprog(char *, char *, int, int); 38 __dead void usage(void); 39 40 /* 41 * which(1) -- find an executable(s) in the user's path 42 * whereis(1) -- find an executable(s) in the default user path 43 * 44 * Return values: 45 * 0 - all executables found 46 * 1 - some found, some not 47 * 2 - none found 48 */ 49 50 int 51 main(int argc, char *argv[]) 52 { 53 char *path; 54 size_t n; 55 int ch, allmatches = 0, notfound = 0, progmode = PROG_WHICH; 56 57 (void)setlocale(LC_ALL, ""); 58 59 while ((ch = getopt(argc, argv, "a")) != -1) 60 switch (ch) { 61 case 'a': 62 allmatches = 1; 63 break; 64 default: 65 usage(); 66 } 67 argc -= optind; 68 argv += optind; 69 70 if (argc == 0) 71 usage(); 72 73 if (strcmp(__progname, "whereis") == 0) { 74 progmode = PROG_WHEREIS; 75 path = _PATH_STDPATH; 76 } else { 77 if ((path = getenv("PATH")) == NULL) 78 err(1, "can't get $PATH from environment"); 79 } 80 81 /* To make access(2) do what we want */ 82 if (setgid(getegid())) 83 err(1, "Can't set gid to %u", getegid()); 84 if (setuid(geteuid())) 85 err(1, "Can't set uid to %u", geteuid()); 86 87 for (n = 0; n < argc; n++) 88 if (findprog(argv[n], path, progmode, allmatches) == 0) 89 notfound++; 90 91 exit((notfound == 0) ? 0 : ((notfound == argc) ? 2 : 1)); 92 } 93 94 int 95 findprog(char *prog, char *path, int progmode, int allmatches) 96 { 97 char *p, filename[MAXPATHLEN]; 98 int proglen, plen, rval = 0; 99 struct stat sbuf; 100 char *pathcpy; 101 102 /* Special case if prog contains '/' */ 103 if (strchr(prog, '/')) { 104 if ((stat(prog, &sbuf) == 0) && S_ISREG(sbuf.st_mode) && 105 access(prog, X_OK) == 0) { 106 (void)puts(prog); 107 return (1); 108 } else { 109 warnx("%s: Command not found.", prog); 110 return (0); 111 } 112 } 113 114 if ((path = strdup(path)) == NULL) 115 err(1, "strdup"); 116 pathcpy = path; 117 118 proglen = strlen(prog); 119 while ((p = strsep(&pathcpy, ":")) != NULL) { 120 if (*p == '\0') 121 p = "."; 122 123 plen = strlen(p); 124 while (p[plen-1] == '/') 125 p[--plen] = '\0'; /* strip trailing '/' */ 126 127 if (plen + 1 + proglen >= sizeof(filename)) { 128 warnc(ENAMETOOLONG, "%s/%s", p, prog); 129 free(path); 130 return (0); 131 } 132 133 snprintf(filename, sizeof(filename), "%s/%s", p, prog); 134 if ((stat(filename, &sbuf) == 0) && S_ISREG(sbuf.st_mode) && 135 access(filename, X_OK) == 0) { 136 (void)puts(filename); 137 rval = 1; 138 if (!allmatches) { 139 free(path); 140 return (rval); 141 } 142 } 143 } 144 (void)free(path); 145 146 /* whereis(1) is silent on failure. */ 147 if (!rval && progmode != PROG_WHEREIS) 148 warnx("%s: Command not found.", prog); 149 return (rval); 150 } 151 152 __dead void 153 usage(void) 154 { 155 (void)fprintf(stderr, "usage: %s [-a] name ...\n", __progname); 156 exit(1); 157 } 158