pwd/pwd.c

   1 /*      $NetBSD: pwd.c,v 1.10 1998/07/28 05:31:26 mycroft Exp $ */
   2
   3 /*
   4  * Copyright (c) 1991, 1993, 1994
   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. All advertising materials mentioning features or use of this software
  16  *    must display the following acknowledgement:
  17  *      This product includes software developed by the University of
  18  *      California, Berkeley and its contributors.
  19  * 4. Neither the name of the University nor the names of its contributors
  20  *    may be used to endorse or promote products derived from this software
  21  *    without specific prior written permission.
  22  *
  23  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  24  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  26  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  27  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  33  * SUCH DAMAGE.
  34  */
  35
  36 #include <sys/cdefs.h>
  37 #ifndef lint
  38 __COPYRIGHT("@(#) Copyright (c) 1991, 1993, 1994\n\
  39         The Regents of the University of California.  All rights reserved.\n");
  40 #endif /* not lint */
  41
  42 #ifndef lint
  43 #if 0
  44 static char sccsid[] = "@(#)pwd.c       8.3 (Berkeley) 4/1/94";
  45 #else
  46 __RCSID("$NetBSD: pwd.c,v 1.10 1998/07/28 05:31:26 mycroft Exp $");
  47 #endif
  48 #endif /* not lint */
  49
  50 #include <err.h>
  51 #include <stdio.h>
  52 #include <stdlib.h>
  53 #include <unistd.h>
  54 #include <sys/param.h>
  55 #include <sys/stat.h>
  56 #include <errno.h>
  57 #include <string.h>
  58
  59 char *getcwd_logical __P((char *, size_t));
  60 void  usage __P((void));
  61 int   main __P((int, char *[]));
  62
  63 int
  64 main(argc, argv)
  65         int argc;
  66         char *argv[];
  67 {
  68         int ch;
  69         int lFlag=0;
  70         char *p = NULL;
  71
  72         while ((ch = getopt(argc, argv, "LP")) != -1)
  73                 switch (ch) {
  74                 case 'L':
  75                         lFlag=1;
  76                         break;
  77                 case 'P':
  78                         lFlag=0;
  79                         break;
  80                 case '?':
  81                 default:
  82                         usage();
  83                 }
  84         argc -= optind;
  85         argv += optind;
  86
  87         if (argc != 0)
  88                 usage();
  89
  90         if (lFlag)
  91                 p = getcwd_logical(NULL, 0);
  92         else
  93                 p = getcwd(NULL, 0);
  94
  95         if (p == NULL) err(1, "%s", "");
  96
  97         (void)printf("%s\n", p);
  98
  99         exit(0);
 100         /* NOTREACHED */
 101 }
 102
 103 char *
 104 getcwd_logical(pt, size)
 105         char *pt;
 106         size_t size;
 107 {
 108         char *pwd;
 109         size_t pwdlen;
 110         dev_t dev;
 111         ino_t ino;
 112         struct stat s;
 113
 114         /* Check $PWD -- if it's right, it's fast. */
 115         if ((pwd = getenv("PWD")) != NULL && pwd[0] == '/' && stat(pwd, &s) != -1) {
 116                 dev = s.st_dev;
 117                 ino = s.st_ino;
 118                 if (stat(".", &s) != -1 && dev == s.st_dev && ino == s.st_ino) {
 119                         pwdlen = strlen(pwd);
 120                         if (pt) {
 121                                 if (!size) {
 122                                         errno = EINVAL;
 123                                         return (NULL);
 124                                 }
 125                                 if (pwdlen + 1 > size) {
 126                                         errno = ERANGE;
 127                                         return (NULL);
 128                                 }
 129                         } else if ((pt = malloc(pwdlen + 1)) == NULL) {
 130                                 errno = ENOMEM;
 131                                 return (NULL);
 132                         }
 133                         memmove(pt, pwd, pwdlen);
 134                         pt[pwdlen] = '\0';
 135                         return (pt);
 136                 }
 137         }
 138
 139         return (NULL);
 140 }
 141
 142 void
 143 usage()
 144 {
 145         (void)fprintf(stderr, "usage: pwd [-LP]\n");
 146         exit(1);
 147         /* NOTREACHED */
 148 }