1 /** 2 * Copyright (c) 2000 Dan Papasian. All rights reserved. 3 * 4 * Redistribution and use in source and binary forms, with or without 5 * modification, are permitted provided that the following conditions 6 * are met: 7 * 1. Redistributions of source code must retain the above copyright 8 * notice, this list of conditions and the following disclaimer. 9 * 2. Redistributions in binary form must reproduce the above copyright 10 * notice, this list of conditions and the following disclaimer in the 11 * documentation and/or other materials provided with the distribution. 12 * 3. The name of the author may not be used to endorse or promote products 13 * derived from this software without specific prior written permission. 14 * 15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 16 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 17 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 18 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 19 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 20 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 21 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 22 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 23 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 24 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 25 * $FreeBSD: src/usr.bin/which/which.c,v 1.5 2002/06/30 06:02:39 tjr Exp $"); 26 * $DragonFly: src/usr.bin/which/which.c,v 1.1 2004/03/25 16:18:40 drhodus Exp $ 27 */ 28 29 #include <sys/cdefs.h> 30 31 32 #include <sys/stat.h> 33 #include <sys/param.h> 34 35 #include <err.h> 36 #include <stdio.h> 37 #include <stdlib.h> 38 #include <string.h> 39 #include <unistd.h> 40 41 static void usage(void); 42 static int print_matches(char *, char *); 43 44 int silent; 45 int allpaths; 46 47 int 48 main(int argc, char **argv) 49 { 50 char *p, *path; 51 ssize_t pathlen; 52 int opt, status; 53 54 status = EXIT_SUCCESS; 55 56 /* If called without args, die silently to conform */ 57 if (argc < 2) 58 exit(EXIT_FAILURE); 59 60 while ((opt = getopt(argc, argv, "as")) != -1) { 61 switch (opt) { 62 case 'a': 63 allpaths = 1; 64 break; 65 case 's': 66 silent = 1; 67 break; 68 default: 69 usage(); 70 break; 71 } 72 } 73 74 argv += optind; 75 argc -= optind; 76 77 if ((p = getenv("PATH")) == NULL) 78 exit(EXIT_FAILURE); 79 pathlen = strlen(p) + 1; 80 path = malloc(pathlen); 81 if (path == NULL) 82 err(EXIT_FAILURE, NULL); 83 84 if (argc == 0) 85 status = EXIT_FAILURE; 86 87 while (argc > 0) { 88 memcpy(path, p, pathlen); 89 90 if (strlen(*argv) >= FILENAME_MAX || 91 print_matches(path, *argv) == -1) 92 status = EXIT_FAILURE; 93 94 argv++; 95 argc--; 96 } 97 98 exit(status); 99 } 100 101 static void 102 usage(void) 103 { 104 105 errx(EXIT_FAILURE, "usage: which [-as] program ..."); 106 } 107 108 static int 109 is_there(char *candidate) 110 { 111 struct stat fin; 112 113 /* XXX work around access(2) false positives for superuser */ 114 if (access(candidate, X_OK) == 0 && 115 stat(candidate, &fin) == 0 && 116 S_ISREG(fin.st_mode) && 117 (getuid() != 0 || 118 (fin.st_mode & (S_IXUSR | S_IXGRP | S_IXOTH)) != 0)) { 119 if (!silent) 120 printf("%s\n", candidate); 121 return (1); 122 } 123 return (0); 124 } 125 126 static int 127 print_matches(char *path, char *filename) 128 { 129 char candidate[PATH_MAX]; 130 const char *d; 131 int found; 132 133 if (strchr(filename, '/') != NULL) 134 return (is_there(filename) ? 0 : -1); 135 found = 0; 136 while ((d = strsep(&path, ":")) != NULL) { 137 if (*d == '\0') 138 d = "."; 139 if (snprintf(candidate, sizeof(candidate), "%s/%s", d, 140 filename) >= (int)sizeof(candidate)) 141 continue; 142 if (is_there(candidate)) { 143 found = 1; 144 if (!allpaths) 145 break; 146 } 147 } 148 return (found ? 0 : -1); 149 } 150 151