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  * 3. All advertising materials mentioning features or use of this software
  14  *    must display the following acknowledgement:
  15  *      This product includes software developed by the University of
  16  *      California, Berkeley and its contributors.
  17  * 4. Neither the name of the University nor the names of its contributors
  18  *    may be used to endorse or promote products derived from this software
  19  *    without specific prior written permission.
  20  *
  21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  31  * SUCH DAMAGE.
  32  *
  33  * @(#) Copyright (c) 1991, 1993, 1994 The Regents of the University of California.  All rights reserved.
  34  * @(#)pwd.c    8.3 (Berkeley) 4/1/94
  35  * $FreeBSD: src/bin/pwd/pwd.c,v 1.9.2.3 2002/06/17 11:04:22 tjr Exp $
  36  * $DragonFly: src/bin/pwd/pwd.c,v 1.5 2005/03/05 21:58:20 liamfoy Exp $
  37  */
  38
  39 #include <sys/param.h>
  40 #include <sys/types.h>
  41 #include <sys/stat.h>
  42
  43 #include <err.h>
  44 #include <errno.h>
  45 #include <limits.h>
  46 #include <stdio.h>
  47 #include <stdlib.h>
  48 #include <string.h>
  49 #include <unistd.h>
  50
  51 static char     *getcwd_logical(void);
  52 static void     usage(void);
  53
  54 int
  55 main(int argc, char *argv[])
  56 {
  57         int physical;
  58         int ch;
  59         char *p;
  60         char buf[PATH_MAX];
  61
  62         if (strcmp(getprogname(), "realpath") == 0) {
  63                 if (argc != 2)
  64                         usage();
  65                 if ((p = realpath(argv[1], buf)) == NULL)
  66                         err(1, "%s", argv[1]);
  67                 printf("%s\n", p);
  68                 exit(0);
  69         }
  70
  71         physical = 1;
  72         while ((ch = getopt(argc, argv, "LP")) != -1)
  73                 switch (ch) {
  74                 case 'L':
  75                         physical = 0;
  76                         break;
  77                 case 'P':
  78                         physical = 1;
  79                         break;
  80                 case '?':
  81                 default:
  82                         usage();
  83                 }
  84         argc -= optind;
  85         argv += optind;
  86
  87         if (argc != 0)
  88                 usage();
  89
  90         /*
  91          * If we're trying to find the logical current directory and that
  92          * fails, behave as if -P was specified.
  93          */
  94         if ((!physical && (p = getcwd_logical()) != NULL) ||
  95             (p = getcwd(NULL, 0)) != NULL)
  96                 printf("%s\n", p);
  97         else
  98                 err(1, ".");
  99
 100         exit(0);
 101 }
 102
 103 static void
 104 usage(void)
 105 {
 106         if (strcmp(getprogname(), "realpath") == 0)
 107                 fprintf(stderr, "usage: realpath [path]\n");
 108         else
 109                 fprintf(stderr, "usage: pwd [-LP]\n");
 110         exit(1);
 111 }
 112
 113 static char *
 114 getcwd_logical(void)
 115 {
 116         struct stat logic, phy;
 117         char *pwd;
 118
 119         /*
 120          * Check that $PWD is an absolute logical pathname referring to
 121          * the current working directory.
 122          */
 123         if ((pwd = getenv("PWD")) != NULL && *pwd == '/') {
 124                 if (stat(pwd, &logic) == -1 || stat(".", &phy) == -1)
 125                         return (NULL);
 126                 if (logic.st_dev == phy.st_dev && logic.st_ino == phy.st_ino)
 127                         return (pwd);
 128         }
 129
 130         errno = ENOENT;
 131         return (NULL);
 132 }