xref: /freebsd/bin/pwd/pwd.c (revision 8ab2f5ecc596131f6ca790d6ae35540c06ed7985)
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("$FreeBSD$");
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 	physical = 1;
65 	while ((ch = getopt(argc, argv, "LP")) != -1)
66 		switch (ch) {
67 		case 'L':
68 			physical = 0;
69 			break;
70 		case 'P':
71 			physical = 1;
72 			break;
73 		case '?':
74 		default:
75 			usage();
76 		}
77 	argc -= optind;
78 	argv += optind;
79 
80 	if (argc != 0)
81 		usage();
82 
83 	/*
84 	 * If we're trying to find the logical current directory and that
85 	 * fails, behave as if -P was specified.
86 	 */
87 	if ((!physical && (p = getcwd_logical()) != NULL) ||
88 	    (p = getcwd(NULL, 0)) != NULL)
89 		printf("%s\n", p);
90 	else
91 		err(1, ".");
92 
93 	exit(0);
94 }
95 
96 void
97 usage(void)
98 {
99 
100 	(void)fprintf(stderr, "usage: pwd [-LP]\n");
101   	exit(1);
102 }
103 
104 static char *
105 getcwd_logical(void)
106 {
107 	struct stat lg, phy;
108 	char *pwd;
109 
110 	/*
111 	 * Check that $PWD is an absolute logical pathname referring to
112 	 * the current working directory.
113 	 */
114 	if ((pwd = getenv("PWD")) != NULL && *pwd == '/') {
115 		if (stat(pwd, &lg) == -1 || stat(".", &phy) == -1)
116 			return (NULL);
117 		if (lg.st_dev == phy.st_dev && lg.st_ino == phy.st_ino)
118 			return (pwd);
119 	}
120 
121 	errno = ENOENT;
122 	return (NULL);
123 }
124