1 /* $OpenBSD: which.c,v 1.27 2019/01/25 00:19:27 millert Exp $ */ 2 3 /* 4 * Copyright (c) 1997 Todd C. Miller <millert@openbsd.org> 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 <limits.h> 25 #include <paths.h> 26 #include <stdio.h> 27 #include <stdlib.h> 28 #include <string.h> 29 #include <unistd.h> 30 31 #define PROG_WHICH 1 32 #define PROG_WHEREIS 2 33 34 extern char *__progname; 35 36 int findprog(char *, char *, int, int); 37 static void __dead usage(void); 38 39 /* 40 * which(1) -- find an executable(s) in the user's path 41 * whereis(1) -- find an executable(s) in the default user path 42 * 43 * Return values: 44 * 0 - all executables found 45 * 1 - some found, some not 46 * 2 - none found 47 */ 48 49 int 50 main(int argc, char *argv[]) 51 { 52 char *path; 53 size_t n; 54 int ch, allmatches = 0, notfound = 0, progmode = PROG_WHICH; 55 56 while ((ch = getopt(argc, argv, "a")) != -1) 57 switch (ch) { 58 case 'a': 59 allmatches = 1; 60 break; 61 default: 62 usage(); 63 } 64 argc -= optind; 65 argv += optind; 66 67 if (argc == 0) 68 usage(); 69 70 if (strcmp(__progname, "whereis") == 0) { 71 progmode = PROG_WHEREIS; 72 path = _PATH_STDPATH; 73 } else { 74 if ((path = getenv("PATH")) == NULL || *path == '\0') 75 path = _PATH_DEFPATH; 76 } 77 78 /* To make access(2) do what we want */ 79 if (setgid(getegid())) 80 err(1, "Can't set gid to %u", getegid()); 81 if (setuid(geteuid())) 82 err(1, "Can't set uid to %u", geteuid()); 83 84 if (pledge("stdio rpath", NULL) == -1) 85 err(2, "pledge"); 86 87 for (n = 0; n < argc; n++) 88 if (findprog(argv[n], path, progmode, allmatches) == 0) 89 notfound++; 90 91 return ((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[PATH_MAX]; 98 int len, 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 while ((p = strsep(&pathcpy, ":")) != NULL) { 119 if (*p == '\0') 120 p = "."; 121 122 len = strlen(p); 123 while (len > 0 && p[len-1] == '/') 124 p[--len] = '\0'; /* strip trailing '/' */ 125 126 len = snprintf(filename, sizeof(filename), "%s/%s", p, prog); 127 if (len < 0 || len >= sizeof(filename)) { 128 warnc(ENAMETOOLONG, "%s/%s", p, prog); 129 free(path); 130 return (0); 131 } 132 if ((stat(filename, &sbuf) == 0) && S_ISREG(sbuf.st_mode) && 133 access(filename, X_OK) == 0) { 134 (void)puts(filename); 135 rval = 1; 136 if (!allmatches) { 137 free(path); 138 return (rval); 139 } 140 } 141 } 142 (void)free(path); 143 144 /* whereis(1) is silent on failure. */ 145 if (!rval && progmode != PROG_WHEREIS) 146 warnx("%s: Command not found.", prog); 147 return (rval); 148 } 149 150 static void __dead 151 usage(void) 152 { 153 (void)fprintf(stderr, "usage: %s [-a] name ...\n", __progname); 154 exit(1); 155 } 156