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#include <sys/param.h>
33#include <sys/stat.h>
34#include <sys/types.h>
35
36#include <err.h>
37#include <errno.h>
38#include <stdio.h>
39#include <stdlib.h>
40#include <unistd.h>
41
42static char *getcwd_logical(void);
43void usage(void);
44
45int
46main(int argc, char *argv[])
47{
48	int physical;
49	int ch;
50	char *p;
51
52	physical = 1;
53	while ((ch = getopt(argc, argv, "LP")) != -1)
54		switch (ch) {
55		case 'L':
56			physical = 0;
57			break;
58		case 'P':
59			physical = 1;
60			break;
61		case '?':
62		default:
63			usage();
64		}
65	argc -= optind;
66	argv += optind;
67
68	if (argc != 0)
69		usage();
70
71	/*
72	 * If we're trying to find the logical current directory and that
73	 * fails, behave as if -P was specified.
74	 */
75	if ((!physical && (p = getcwd_logical()) != NULL) ||
76	    (p = getcwd(NULL, 0)) != NULL)
77		printf("%s\n", p);
78	else
79		err(1, ".");
80
81	exit(0);
82}
83
84void __dead2
85usage(void)
86{
87
88	(void)fprintf(stderr, "usage: pwd [-L | -P]\n");
89  	exit(1);
90}
91
92static char *
93getcwd_logical(void)
94{
95	struct stat lg, phy;
96	char *pwd;
97
98	/*
99	 * Check that $PWD is an absolute logical pathname referring to
100	 * the current working directory.
101	 */
102	if ((pwd = getenv("PWD")) != NULL && *pwd == '/') {
103		if (stat(pwd, &lg) == -1 || stat(".", &phy) == -1)
104			return (NULL);
105		if (lg.st_dev == phy.st_dev && lg.st_ino == phy.st_ino)
106			return (pwd);
107	}
108
109	errno = ENOENT;
110	return (NULL);
111}
112