xref: /netbsd-src/usr.bin/dirname/dirname.c (revision 1c9b56c830954ccf3b57004ac65562e3d6afacf6)
1 /*	$NetBSD: dirname.c,v 1.9 2005/02/17 17:41:34 xtraeme 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\n\
35 	The Regents of the University of California.  All rights reserved.\n");
36 #endif /* not lint */
37 
38 #ifndef lint
39 #if 0
40 static char sccsid[] = "@(#)dirname.c	8.4 (Berkeley) 5/4/95";
41 #endif
42 __RCSID("$NetBSD: dirname.c,v 1.9 2005/02/17 17:41:34 xtraeme Exp $");
43 #endif /* not lint */
44 
45 #include <stdio.h>
46 #include <stdlib.h>
47 #include <locale.h>
48 #include <unistd.h>
49 
50 static void usage(void);
51 
52 int
53 main(int argc, char **argv)
54 {
55 	register char *p;
56 	int ch;
57 
58 	setlocale(LC_ALL, "");
59 
60 	while ((ch = getopt(argc, argv, "")) != -1)
61 		switch(ch) {
62 		case '?':
63 		default:
64 			usage();
65 		}
66 	argc -= optind;
67 	argv += optind;
68 
69 	if (argc != 1)
70 		usage();
71 
72 	/*
73 	 * (1) If string is //, skip steps (2) through (5).
74 	 * (2) If string consists entirely of slash characters, string
75 	 *     shall be set to a single slash character.  In this case,
76 	 *     skip steps (3) through (8).
77 	 */
78 	for (p = *argv;; ++p) {
79 		if (!*p) {
80 			if (p > *argv)
81 				(void)printf("/\n");
82 			else
83 				(void)printf(".\n");
84 			exit(0);
85 		}
86 		if (*p != '/')
87 			break;
88 	}
89 
90 	/*
91 	 * (3) If there are any trailing slash characters in string, they
92 	 *     shall be removed.
93 	 */
94 	for (; *p; ++p);
95 	while (*--p == '/')
96 		continue;
97 	*++p = '\0';
98 
99 	/*
100 	 * (4) If there are no slash characters remaining in string,
101 	 *     string shall be set to a single period character.  In this
102 	 *     case skip steps (5) through (8).
103 	 *
104 	 * (5) If there are any trailing nonslash characters in string,
105 	 *     they shall be removed.
106 	 */
107 	while (--p >= *argv)
108 		if (*p == '/')
109 			break;
110 	++p;
111 	if (p == *argv) {
112 		(void)printf(".\n");
113 		exit(0);
114 	}
115 
116 	/*
117 	 * (6) If the remaining string is //, it is implementation defined
118 	 *     whether steps (7) and (8) are skipped or processed.
119 	 *
120 	 * This case has already been handled, as part of steps (1) and (2).
121 	 */
122 
123 	/*
124 	 * (7) If there are any trailing slash characters in string, they
125 	 *     shall be removed.
126 	 */
127 	while (--p >= *argv)
128 		if (*p != '/')
129 			break;
130 	++p;
131 
132 	/*
133 	 * (8) If the remaining string is empty, string shall be set to
134 	 *     a single slash character.
135 	 */
136 	*p = '\0';
137 	(void)printf("%s\n", p == *argv ? "/" : *argv);
138 	exit(0);
139 }
140 
141 static void
142 usage(void)
143 {
144 
145 	(void)fprintf(stderr, "usage: dirname path\n");
146 	exit(1);
147 }
148 
149