bin/pwd/pwd.c

   1 /*
   2  * Copyright (c) 1991, 1993, 1994
   3  *      The Regents of the University of California.  All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  * 4. Neither the name of the University nor the names of its contributors
  14  *    may be used to endorse or promote products derived from this software
  15  *    without specific prior written permission.
  16  *
  17  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  27  * SUCH DAMAGE.
  28  *
  29  * @(#) Copyright (c) 1991, 1993, 1994 The Regents of the University of California.  All rights reserved.
  30  * @(#)pwd.c    8.3 (Berkeley) 4/1/94
  31  * $FreeBSD: src/bin/pwd/pwd.c,v 1.9.2.3 2002/06/17 11:04:22 tjr Exp $
  32  * $DragonFly: src/bin/pwd/pwd.c,v 1.5 2005/03/05 21:58:20 liamfoy Exp $
  33  */
  34
  35 #include <sys/param.h>
  36 #include <sys/types.h>
  37 #include <sys/stat.h>
  38
  39 #include <err.h>
  40 #include <errno.h>
  41 #include <limits.h>
  42 #include <stdio.h>
  43 #include <stdlib.h>
  44 #include <string.h>
  45 #include <unistd.h>
  46
  47 static char     *getcwd_logical(void);
  48 static void     usage(void);
  49
  50 int
  51 main(int argc, char *argv[])
  52 {
  53         int physical;
  54         int ch;
  55         char *p;
  56         char buf[PATH_MAX];
  57
  58         if (strcmp(getprogname(), "realpath") == 0) {
  59                 if (argc != 2)
  60                         usage();
  61                 if ((p = realpath(argv[1], buf)) == NULL)
  62                         err(1, "%s", argv[1]);
  63                 printf("%s\n", p);
  64                 exit(0);
  65         }
  66
  67         physical = 1;
  68         while ((ch = getopt(argc, argv, "LP")) != -1)
  69                 switch (ch) {
  70                 case 'L':
  71                         physical = 0;
  72                         break;
  73                 case 'P':
  74                         physical = 1;
  75                         break;
  76                 case '?':
  77                 default:
  78                         usage();
  79                 }
  80         argc -= optind;
  81         argv += optind;
  82
  83         if (argc != 0)
  84                 usage();
  85
  86         /*
  87          * If we're trying to find the logical current directory and that
  88          * fails, behave as if -P was specified.
  89          */
  90         if ((!physical && (p = getcwd_logical()) != NULL) ||
  91             (p = getcwd(NULL, 0)) != NULL)
  92                 printf("%s\n", p);
  93         else
  94                 err(1, ".");
  95
  96         exit(0);
  97 }
  98
  99 static void
 100 usage(void)
 101 {
 102         if (strcmp(getprogname(), "realpath") == 0)
 103                 fprintf(stderr, "usage: realpath [path]\n");
 104         else
 105                 fprintf(stderr, "usage: pwd [-LP]\n");
 106         exit(1);
 107 }
 108
 109 static char *
 110 getcwd_logical(void)
 111 {
 112         struct stat logic, phy;
 113         char *pwd;
 114
 115         /*
 116          * Check that $PWD is an absolute logical pathname referring to
 117          * the current working directory.
 118          */
 119         if ((pwd = getenv("PWD")) != NULL && *pwd == '/') {
 120                 if (stat(pwd, &logic) == -1 || stat(".", &phy) == -1)
 121                         return (NULL);
 122                 if (logic.st_dev == phy.st_dev && logic.st_ino == phy.st_ino)
 123                         return (pwd);
 124         }
 125
 126         errno = ENOENT;
 127         return (NULL);
 128 }