xref: /freebsd/bin/pwd/pwd.c (revision eb69d1f144a6fcc765d1b9d44a5ae8082353e70b)
1 /*-
2  * SPDX-License-Identifier: BSD-3-Clause
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. 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 #if 0
33 #ifndef lint
34 static char const copyright[] =
35 "@(#) Copyright (c) 1991, 1993, 1994\n\
36 	The Regents of the University of California.  All rights reserved.\n";
37 #endif /* not lint */
38 
39 #ifndef lint
40 static char sccsid[] = "@(#)pwd.c	8.3 (Berkeley) 4/1/94";
41 #endif /* not lint */
42 #endif
43 #include <sys/cdefs.h>
44 __FBSDID("$FreeBSD$");
45 
46 #include <sys/param.h>
47 #include <sys/stat.h>
48 #include <sys/types.h>
49 
50 #include <err.h>
51 #include <errno.h>
52 #include <stdio.h>
53 #include <stdlib.h>
54 #include <unistd.h>
55 
56 static char *getcwd_logical(void);
57 void usage(void);
58 
59 int
60 main(int argc, char *argv[])
61 {
62 	int physical;
63 	int ch;
64 	char *p;
65 
66 	physical = 1;
67 	while ((ch = getopt(argc, argv, "LP")) != -1)
68 		switch (ch) {
69 		case 'L':
70 			physical = 0;
71 			break;
72 		case 'P':
73 			physical = 1;
74 			break;
75 		case '?':
76 		default:
77 			usage();
78 		}
79 	argc -= optind;
80 	argv += optind;
81 
82 	if (argc != 0)
83 		usage();
84 
85 	/*
86 	 * If we're trying to find the logical current directory and that
87 	 * fails, behave as if -P was specified.
88 	 */
89 	if ((!physical && (p = getcwd_logical()) != NULL) ||
90 	    (p = getcwd(NULL, 0)) != NULL)
91 		printf("%s\n", p);
92 	else
93 		err(1, ".");
94 
95 	exit(0);
96 }
97 
98 void
99 usage(void)
100 {
101 
102 	(void)fprintf(stderr, "usage: pwd [-L | -P]\n");
103   	exit(1);
104 }
105 
106 static char *
107 getcwd_logical(void)
108 {
109 	struct stat lg, phy;
110 	char *pwd;
111 
112 	/*
113 	 * Check that $PWD is an absolute logical pathname referring to
114 	 * the current working directory.
115 	 */
116 	if ((pwd = getenv("PWD")) != NULL && *pwd == '/') {
117 		if (stat(pwd, &lg) == -1 || stat(".", &phy) == -1)
118 			return (NULL);
119 		if (lg.st_dev == phy.st_dev && lg.st_ino == phy.st_ino)
120 			return (pwd);
121 	}
122 
123 	errno = ENOENT;
124 	return (NULL);
125 }
126