usr.bin/whereis/whereis.c

   1 /*      $NetBSD: whereis.c,v 1.21 2008/10/17 10:53:26 apb Exp $ */
   2
   3 /*-
   4  * Copyright (c) 1993
   5  *      The Regents of the University of California.  All rights reserved.
   6  *
   7  * Redistribution and use in source and binary forms, with or without
   8  * modification, are permitted provided that the following conditions
   9  * are met:
  10  * 1. Redistributions of source code must retain the above copyright
  11  *    notice, this list of conditions and the following disclaimer.
  12  * 2. Redistributions in binary form must reproduce the above copyright
  13  *    notice, this list of conditions and the following disclaimer in the
  14  *    documentation and/or other materials provided with the distribution.
  15  * 3. Neither the name of the University nor the names of its contributors
  16  *    may be used to endorse or promote products derived from this software
  17  *    without specific prior written permission.
  18  *
  19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  29  * SUCH DAMAGE.
  30  */
  31
  32 #include <sys/cdefs.h>
  33 #ifndef lint
  34 __COPYRIGHT("@(#) Copyright (c) 1993\
  35  The Regents of the University of California.  All rights reserved.");
  36 #endif /* not lint */
  37
  38 #ifndef lint
  39 #if 0
  40 static char sccsid[] = "@(#)whereis.c   8.3 (Berkeley) 5/4/95";
  41 #endif
  42 __RCSID("$NetBSD: whereis.c,v 1.21 2008/10/17 10:53:26 apb Exp $");
  43 #endif /* not lint */
  44
  45 #include <sys/param.h>
  46 #include <sys/stat.h>
  47 #include <sys/sysctl.h>
  48
  49 #include <err.h>
  50 #include <errno.h>
  51 #include <stdio.h>
  52 #include <stdlib.h>
  53 #include <string.h>
  54 #include <unistd.h>
  55
  56 static void usage(void) __dead;
  57
  58 int
  59 main(int argc, char *argv[])
  60 {
  61         struct stat sb;
  62         size_t len;
  63         int ch, mib[2];
  64         char *p, *std, path[MAXPATHLEN];
  65         const char *t;
  66         int which = strcmp(getprogname(), "which") == 0;
  67         int useenvpath = which, found = 0;
  68         gid_t egid = getegid();
  69         uid_t euid = geteuid();
  70
  71         /* To make access(2) do what we want */
  72         if (setgid(egid) == -1)
  73                 err(1, "Can't set gid to %lu", (unsigned long)egid);
  74         if (setuid(euid) == -1)
  75                 err(1, "Can't set uid to %lu", (unsigned long)euid);
  76
  77         while ((ch = getopt(argc, argv, "ap")) != -1)
  78                 switch (ch) {
  79                 case 'a':
  80                         which = 0;
  81                         break;
  82                 case 'p':
  83                         useenvpath = 1; /* use environment for PATH */
  84                         break;
  85
  86                 case '?':
  87                 default:
  88                         usage();
  89                 }
  90         argc -= optind;
  91         argv += optind;
  92
  93         if (argc == 0)
  94                 usage();
  95
  96         if (useenvpath) {
  97                 if ((std = getenv("PATH")) == NULL)
  98                         errx(1, "PATH environment variable is not set");
  99         } else {
 100                 /* Retrieve the standard path. */
 101                 mib[0] = CTL_USER;
 102                 mib[1] = USER_CS_PATH;
 103                 if (sysctl(mib, 2, NULL, &len, NULL, 0) == -1)
 104                         err(1, "sysctl: user.cs_path");
 105                 if (len == 0)
 106                         errx(1, "sysctl: user.cs_path (zero length)");
 107                 if ((std = malloc(len)) == NULL)
 108                         err(1, NULL);
 109                 if (sysctl(mib, 2, std, &len, NULL, 0) == -1)
 110                         err(1, "sysctl: user.cs_path");
 111         }
 112
 113         /* For each path, for each program... */
 114         for (; *argv; ++argv) {
 115                 if (**argv == '/') {
 116                         if (stat(*argv, &sb) == -1)
 117                                 continue; /* next argv */
 118                         if (!S_ISREG(sb.st_mode))
 119                                 continue; /* next argv */
 120                         if (access(*argv, X_OK) == -1)
 121                                 continue; /* next argv */
 122                         (void)printf("%s\n", *argv);
 123                         found++;
 124                         if (which)
 125                                 continue; /* next argv */
 126                 } else for (p = std; p; ) {
 127                         t = p;
 128                         if ((p = strchr(p, ':')) != NULL) {
 129                                 *p = '\0';
 130                                 if (t == p)
 131                                         t = ".";
 132                         } else
 133                                 if (strlen(t) == 0)
 134                                         t = ".";
 135                         (void)snprintf(path, sizeof(path), "%s/%s", t, *argv);
 136                         len = snprintf(path, sizeof(path), "%s/%s", t, *argv);
 137                         if (p)
 138                                 *p++ = ':';
 139                         if (len >= sizeof(path))
 140                                 continue; /* next p */
 141                         if (stat(path, &sb) == -1)
 142                                 continue; /* next p */
 143                         if (!S_ISREG(sb.st_mode))
 144                                 continue; /* next p */
 145                         if (access(path, X_OK) == -1)
 146                                 continue; /* next p */
 147                         (void)printf("%s\n", path);
 148                         found++;
 149                         if (which)
 150                                 break; /* next argv */
 151                 }
 152         }
 153
 154         return ((found == 0) ? 3 : ((found >= argc) ? 0 : 2));
 155 }
 156
 157 static void
 158 usage(void)
 159 {
 160
 161         (void)fprintf(stderr, "Usage: %s [-ap] program [...]\n", getprogname());
 162         exit(1);
 163 }