1 /* $OpenBSD: which.c,v 1.25 2016/01/14 22:02:13 millert 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/stat.h> 20 #include <sys/sysctl.h> 21 22 #include <err.h> 23 #include <errno.h> 24 #include <locale.h> 25 #include <paths.h> 26 #include <stdio.h> 27 #include <stdlib.h> 28 #include <string.h> 29 #include <unistd.h> 30 #include <limits.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 || *path == '\0') 78 path = _PATH_DEFPATH; 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 if (pledge("stdio rpath", NULL) == -1) 88 err(2, "pledge"); 89 90 for (n = 0; n < argc; n++) 91 if (findprog(argv[n], path, progmode, allmatches) == 0) 92 notfound++; 93 94 exit((notfound == 0) ? 0 : ((notfound == argc) ? 2 : 1)); 95 } 96 97 int 98 findprog(char *prog, char *path, int progmode, int allmatches) 99 { 100 char *p, filename[PATH_MAX]; 101 int len, rval = 0; 102 struct stat sbuf; 103 char *pathcpy; 104 105 /* Special case if prog contains '/' */ 106 if (strchr(prog, '/')) { 107 if ((stat(prog, &sbuf) == 0) && S_ISREG(sbuf.st_mode) && 108 access(prog, X_OK) == 0) { 109 (void)puts(prog); 110 return (1); 111 } else { 112 warnx("%s: Command not found.", prog); 113 return (0); 114 } 115 } 116 117 if ((path = strdup(path)) == NULL) 118 err(1, "strdup"); 119 pathcpy = path; 120 121 while ((p = strsep(&pathcpy, ":")) != NULL) { 122 if (*p == '\0') 123 p = "."; 124 125 len = strlen(p); 126 while (len > 0 && p[len-1] == '/') 127 p[--len] = '\0'; /* strip trailing '/' */ 128 129 len = snprintf(filename, sizeof(filename), "%s/%s", p, prog); 130 if (len < 0 || len >= sizeof(filename)) { 131 warnc(ENAMETOOLONG, "%s/%s", p, prog); 132 free(path); 133 return (0); 134 } 135 if ((stat(filename, &sbuf) == 0) && S_ISREG(sbuf.st_mode) && 136 access(filename, X_OK) == 0) { 137 (void)puts(filename); 138 rval = 1; 139 if (!allmatches) { 140 free(path); 141 return (rval); 142 } 143 } 144 } 145 (void)free(path); 146 147 /* whereis(1) is silent on failure. */ 148 if (!rval && progmode != PROG_WHEREIS) 149 warnx("%s: Command not found.", prog); 150 return (rval); 151 } 152 153 __dead void 154 usage(void) 155 { 156 (void)fprintf(stderr, "usage: %s [-a] name ...\n", __progname); 157 exit(1); 158 } 159