| 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 | */ |
| 26 | |
| 27 | #include <sys/cdefs.h> |
| 28 | |
| 29 | __FBSDID("$FreeBSD: head/usr.bin/which/which.c 227245 2011-11-06 18:50:26Z ed $"); |
| 30 | |
| 31 | #include <sys/stat.h> |
| 32 | #include <sys/param.h> |
| 33 | |
| 34 | #include <err.h> |
| 35 | #include <stdio.h> |
| 36 | #include <stdlib.h> |
| 37 | #include <string.h> |
| 38 | #include <unistd.h> |
| 39 | |
| 40 | static void usage(void); |
| 41 | static int print_matches(char *, char *); |
| 42 | |
| 43 | static int silent; |
| 44 | static int allpaths; |
| 45 | |
| 46 | int |
| 47 | main(int argc, char **argv) |
| 48 | { |
| 49 | char *p, *path; |
| 50 | ssize_t pathlen; |
| 51 | int opt, status; |
| 52 | |
| 53 | status = EXIT_SUCCESS; |
| 54 | |
| 55 | while ((opt = getopt(argc, argv, "as")) != -1) { |
| 56 | switch (opt) { |
| 57 | case 'a': |
| 58 | allpaths = 1; |
| 59 | break; |
| 60 | case 's': |
| 61 | silent = 1; |
| 62 | break; |
| 63 | default: |
| 64 | usage(); |
| 65 | break; |
| 66 | } |
| 67 | } |
| 68 | |
| 69 | argv += optind; |
| 70 | argc -= optind; |
| 71 | |
| 72 | if (argc == 0) |
| 73 | usage(); |
| 74 | |
| 75 | if ((p = getenv("PATH")) == NULL) |
| 76 | exit(EXIT_FAILURE); |
| 77 | pathlen = strlen(p) + 1; |
| 78 | path = malloc(pathlen); |
| 79 | if (path == NULL) |
| 80 | err(EXIT_FAILURE, NULL); |
| 81 | |
| 82 | while (argc > 0) { |
| 83 | memcpy(path, p, pathlen); |
| 84 | |
| 85 | if (strlen(*argv) >= FILENAME_MAX || |
| 86 | print_matches(path, *argv) == -1) |
| 87 | status = EXIT_FAILURE; |
| 88 | |
| 89 | argv++; |
| 90 | argc--; |
| 91 | } |
| 92 | |
| 93 | exit(status); |
| 94 | } |
| 95 | |
| 96 | static void |
| 97 | usage(void) |
| 98 | { |
| 99 | |
| 100 | (void)fprintf(stderr, "usage: which [-as] program ...\n"); |
| 101 | exit(EXIT_FAILURE); |
| 102 | } |
| 103 | |
| 104 | static int |
| 105 | is_there(char *candidate) |
| 106 | { |
| 107 | struct stat fin; |
| 108 | |
| 109 | /* XXX work around access(2) false positives for superuser */ |
| 110 | if (access(candidate, X_OK) == 0 && |
| 111 | stat(candidate, &fin) == 0 && |
| 112 | S_ISREG(fin.st_mode) && |
| 113 | (getuid() != 0 || |
| 114 | (fin.st_mode & (S_IXUSR | S_IXGRP | S_IXOTH)) != 0)) { |
| 115 | if (!silent) |
| 116 | printf("%s\n", candidate); |
| 117 | return (1); |
| 118 | } |
| 119 | return (0); |
| 120 | } |
| 121 | |
| 122 | static int |
| 123 | print_matches(char *path, char *filename) |
| 124 | { |
| 125 | char candidate[PATH_MAX]; |
| 126 | const char *d; |
| 127 | int found; |
| 128 | |
| 129 | if (strchr(filename, '/') != NULL) |
| 130 | return (is_there(filename) ? 0 : -1); |
| 131 | found = 0; |
| 132 | while ((d = strsep(&path, ":")) != NULL) { |
| 133 | if (*d == '\0') |
| 134 | d = "."; |
| 135 | if (snprintf(candidate, sizeof(candidate), "%s/%s", d, |
| 136 | filename) >= (int)sizeof(candidate)) |
| 137 | continue; |
| 138 | if (is_there(candidate)) { |
| 139 | found = 1; |
| 140 | if (!allpaths) |
| 141 | break; |
| 142 | } |
| 143 | } |
| 144 | return (found ? 0 : -1); |
| 145 | } |
| 146 | |