xref: /netbsd-src/usr.bin/dirname/dirname.c (revision 3b01aba77a7a698587faaae455bbfe740923c1f5)
1 /*	$NetBSD: dirname.c,v 1.7 1997/10/18 13:21:41 lukem 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. All advertising materials mentioning features or use of this software
16  *    must display the following acknowledgement:
17  *	This product includes software developed by the University of
18  *	California, Berkeley and its contributors.
19  * 4. Neither the name of the University nor the names of its contributors
20  *    may be used to endorse or promote products derived from this software
21  *    without specific prior written permission.
22  *
23  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
24  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
27  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33  * SUCH DAMAGE.
34  */
35 
36 #include <sys/cdefs.h>
37 #ifndef lint
38 __COPYRIGHT("@(#) Copyright (c) 1991, 1993, 1994\n\
39 	The Regents of the University of California.  All rights reserved.\n");
40 #endif /* not lint */
41 
42 #ifndef lint
43 #if 0
44 static char sccsid[] = "@(#)dirname.c	8.4 (Berkeley) 5/4/95";
45 #endif
46 __RCSID("$NetBSD: dirname.c,v 1.7 1997/10/18 13:21:41 lukem Exp $");
47 #endif /* not lint */
48 
49 #include <stdio.h>
50 #include <stdlib.h>
51 #include <locale.h>
52 #include <unistd.h>
53 
54 int	main __P((int, char **));
55 static void usage __P((void));
56 
57 int
58 main(argc, argv)
59 	int argc;
60 	char **argv;
61 {
62 	register char *p;
63 	int ch;
64 
65 	setlocale(LC_ALL, "");
66 
67 	while ((ch = getopt(argc, argv, "")) != -1)
68 		switch(ch) {
69 		case '?':
70 		default:
71 			usage();
72 		}
73 	argc -= optind;
74 	argv += optind;
75 
76 	if (argc != 1)
77 		usage();
78 
79 	/*
80 	 * (1) If string is //, skip steps (2) through (5).
81 	 * (2) If string consists entirely of slash characters, string
82 	 *     shall be set to a single slash character.  In this case,
83 	 *     skip steps (3) through (8).
84 	 */
85 	for (p = *argv;; ++p) {
86 		if (!*p) {
87 			if (p > *argv)
88 				(void)printf("/\n");
89 			else
90 				(void)printf(".\n");
91 			exit(0);
92 		}
93 		if (*p != '/')
94 			break;
95 	}
96 
97 	/*
98 	 * (3) If there are any trailing slash characters in string, they
99 	 *     shall be removed.
100 	 */
101 	for (; *p; ++p);
102 	while (*--p == '/')
103 		continue;
104 	*++p = '\0';
105 
106 	/*
107 	 * (4) If there are no slash characters remaining in string,
108 	 *     string shall be set to a single period character.  In this
109 	 *     case skip steps (5) through (8).
110 	 *
111 	 * (5) If there are any trailing nonslash characters in string,
112 	 *     they shall be removed.
113 	 */
114 	while (--p >= *argv)
115 		if (*p == '/')
116 			break;
117 	++p;
118 	if (p == *argv) {
119 		(void)printf(".\n");
120 		exit(0);
121 	}
122 
123 	/*
124 	 * (6) If the remaining string is //, it is implementation defined
125 	 *     whether steps (7) and (8) are skipped or processed.
126 	 *
127 	 * This case has already been handled, as part of steps (1) and (2).
128 	 */
129 
130 	/*
131 	 * (7) If there are any trailing slash characters in string, they
132 	 *     shall be removed.
133 	 */
134 	while (--p >= *argv)
135 		if (*p != '/')
136 			break;
137 	++p;
138 
139 	/*
140 	 * (8) If the remaining string is empty, string shall be set to
141 	 *     a single slash character.
142 	 */
143 	*p = '\0';
144 	(void)printf("%s\n", p == *argv ? "/" : *argv);
145 	exit(0);
146 }
147 
148 static void
149 usage()
150 {
151 
152 	(void)fprintf(stderr, "usage: dirname path\n");
153 	exit(1);
154 }
155 
156