1 /* $NetBSD: pwd.c,v 1.22 2011/08/29 14:51:19 joerg 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. 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/cdefs.h>
33 #ifndef lint
34 __COPYRIGHT("@(#) Copyright (c) 1991, 1993, 1994\
35 The Regents of the University of California. All rights reserved.");
36 #endif /* not lint */
37
38 #ifndef lint
39 #if 0
40 static char sccsid[] = "@(#)pwd.c 8.3 (Berkeley) 4/1/94";
41 #else
42 __RCSID("$NetBSD: pwd.c,v 1.22 2011/08/29 14:51:19 joerg Exp $");
43 #endif
44 #endif /* not lint */
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 <locale.h>
53 #include <stdio.h>
54 #include <stdlib.h>
55 #include <string.h>
56 #include <unistd.h>
57
58 static char *getcwd_logical(void);
59 __dead static void usage(void);
60
61 /*
62 * Note that EEE Std 1003.1, 2003 requires that the default be -L.
63 * This is inconsistent with the historic behaviour of everything
64 * except the ksh builtin.
65 * To avoid breaking scripts the default has been kept as -P.
66 * (Some scripts run /bin/pwd in order to get 'pwd -P'.)
67 */
68
69 int
main(int argc,char * argv[])70 main(int argc, char *argv[])
71 {
72 int ch, lFlag;
73 const char *p;
74
75 setprogname(argv[0]);
76 (void)setlocale(LC_ALL, "");
77
78 lFlag = 0;
79 while ((ch = getopt(argc, argv, "LP")) != -1) {
80 switch (ch) {
81 case 'L':
82 lFlag = 1;
83 break;
84 case 'P':
85 lFlag = 0;
86 break;
87 case '?':
88 default:
89 usage();
90 }
91 }
92 argc -= optind;
93 argv += optind;
94
95 if (argc != 0)
96 usage();
97
98 if (lFlag)
99 p = getcwd_logical();
100 else
101 p = NULL;
102 if (p == NULL)
103 p = getcwd(NULL, 0);
104
105 if (p == NULL)
106 err(EXIT_FAILURE, NULL);
107
108 (void)printf("%s\n", p);
109
110 exit(EXIT_SUCCESS);
111 /* NOTREACHED */
112 }
113
114 static char *
getcwd_logical(void)115 getcwd_logical(void)
116 {
117 char *pwd;
118 struct stat s_pwd, s_dot;
119
120 /* Check $PWD -- if it's right, it's fast. */
121 pwd = getenv("PWD");
122 if (pwd == NULL)
123 return NULL;
124 if (pwd[0] != '/')
125 return NULL;
126 if (strstr(pwd, "/./") != NULL)
127 return NULL;
128 if (strstr(pwd, "/../") != NULL)
129 return NULL;
130 if (stat(pwd, &s_pwd) == -1 || stat(".", &s_dot) == -1)
131 return NULL;
132 if (s_pwd.st_dev != s_dot.st_dev || s_pwd.st_ino != s_dot.st_ino)
133 return NULL;
134 return pwd;
135 }
136
137 static void
usage(void)138 usage(void)
139 {
140 (void)fprintf(stderr, "usage: %s [-LP]\n", getprogname());
141 exit(EXIT_FAILURE);
142 /* NOTREACHED */
143 }
144