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
  30 #if 0
  31 #ifndef lint
  32 static char const copyright[] =
  33 "@(#) Copyright (c) 1991, 1993, 1994\n\
  34         The Regents of the University of California.  All rights reserved.\n";
  35 #endif /* not lint */
  36
  37 #ifndef lint
  38 static char sccsid[] = "@(#)pwd.c       8.3 (Berkeley) 4/1/94";
  39 #endif /* not lint */
  40 #endif
  41 #include <sys/cdefs.h>
  42 __FBSDID("$FreeBSD: src/bin/pwd/pwd.c,v 1.25 2005/02/09 17:37:38 ru Exp $");
  43
  44 #include <sys/param.h>
  45 #include <sys/stat.h>
  46 #include <sys/types.h>
  47
  48 #include <err.h>
  49 #include <errno.h>
  50 #include <stdio.h>
  51 #include <stdlib.h>
  52 #include <unistd.h>
  53
  54 static char *getcwd_logical(void);
  55 void usage(void);
  56
  57 int
  58 main(int argc, char *argv[])
  59 {
  60         int physical;
  61         int ch;
  62         char *p;
  63
  64         // 4207130
  65         physical = 0;
  66         while ((ch = getopt(argc, argv, "LP")) != -1)
  67                 switch (ch) {
  68                 case 'L':
  69                         physical = 0;
  70                         break;
  71                 case 'P':
  72                         physical = 1;
  73                         break;
  74                 case '?':
  75                 default:
  76                         usage();
  77                 }
  78         argc -= optind;
  79         argv += optind;
  80
  81         if (argc != 0)
  82                 usage();
  83
  84         /*
  85          * If we're trying to find the logical current directory and that
  86          * fails, behave as if -P was specified.
  87          *
  88          * 4701537: Only fall back if $PWD was actually wrong. We want to
  89          * fail if the path is too long (errno == ENAMETOOLONG).
  90          */
  91         if ((!physical && (p = getcwd_logical()) != NULL) ||
  92             ((physical || errno == ENOENT) && (p = getcwd(NULL, 0)) != NULL))
  93                 printf("%s\n", p);
  94         else
  95                 err(1, ".");
  96
  97         exit(0);
  98 }
  99
 100 void
 101 usage(void)
 102 {
 103
 104         (void)fprintf(stderr, "usage: pwd [-L | -P]\n");
 105         exit(1);
 106 }
 107
 108 static char *
 109 getcwd_logical(void)
 110 {
 111         struct stat lg, phy;
 112         char *pwd;
 113
 114         /*
 115          * Check that $PWD is an absolute logical pathname referring to
 116          * the current working directory.
 117          */
 118         if ((pwd = getenv("PWD")) != NULL && *pwd == '/') {
 119                 if (stat(pwd, &lg) == -1 || stat(".", &phy) == -1)
 120                         return (NULL);
 121                 if (lg.st_dev == phy.st_dev && lg.st_ino == phy.st_ino)
 122                         return (pwd);
 123         }
 124
 125         errno = ENOENT;
 126         return (NULL);
 127 }