xref: /netbsd-src/usr.bin/dirname/dirname.c (revision ae1bfcddc410612bc8c58b807e1830becb69a24c)
1 /*-
2  * Copyright (c) 1991 The Regents of the University of California.
3  * 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  * 3. All advertising materials mentioning features or use of this software
14  *    must display the following acknowledgement:
15  *	This product includes software developed by the University of
16  *	California, Berkeley and its contributors.
17  * 4. Neither the name of the University nor the names of its contributors
18  *    may be used to endorse or promote products derived from this software
19  *    without specific prior written permission.
20  *
21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31  * SUCH DAMAGE.
32  */
33 
34 #ifndef lint
35 char copyright[] =
36 "@(#) Copyright (c) 1991 The Regents of the University of California.\n\
37  All rights reserved.\n";
38 #endif /* not lint */
39 
40 #ifndef lint
41 /*static char sccsid[] = "from: @(#)dirname.c	5.6 (Berkeley) 3/9/91";*/
42 static char rcsid[] = "$Id: dirname.c,v 1.4 1993/10/01 22:23:58 jtc Exp $";
43 #endif /* not lint */
44 
45 #include <stdio.h>
46 #include <stdlib.h>
47 #include <locale.h>
48 
49 static void usage	__P((void));
50 
51 int
52 main(argc, argv)
53 	int argc;
54 	char **argv;
55 {
56 	register char *p;
57 	int ch;
58 
59 	setlocale(LC_ALL, "");
60 
61 	while ((ch = getopt(argc, argv, "")) != -1)
62 		switch(ch) {
63 		case '?':
64 		default:
65 			usage();
66 		}
67 	argc -= optind;
68 	argv += optind;
69 
70 	if (argc != 1)
71 		usage();
72 
73 	/*
74 	 * (1) If string is //, skip steps (2) through (5).
75 	 * (2) If string consists entirely of slash characters, string
76 	 *     shall be set to a single slash character.  In this case,
77 	 *     skip steps (3) through (8).
78 	 */
79 	for (p = *argv;; ++p) {
80 		if (!*p) {
81 			if (p > *argv)
82 				(void)printf("/\n");
83 			else
84 				(void)printf(".\n");
85 			exit(0);
86 		}
87 		if (*p != '/')
88 			break;
89 	}
90 
91 	/*
92 	 * (3) If there are any trailing slash characters in string, they
93 	 *     shall be removed.
94 	 */
95 	for (; *p; ++p)
96 		;
97 	while (*--p == '/')
98 		;
99 	*++p = '\0';
100 
101 	/*
102 	 * (4) If there are no slash characters remaining in string,
103 	 *     string shall be set to a single period character.  In this
104 	 *     case skip steps (5) through (8).
105 	 *
106 	 * (5) If there are any trailing nonslash characters in string,
107 	 *     they shall be removed.
108 	 */
109 	while (--p >= *argv)
110 		if (*p == '/')
111 			break;
112 	++p;
113 	if (p == *argv) {
114 		(void)printf(".\n");
115 		exit(0);
116 	}
117 
118 	/*
119 	 * (6) If the remaining string is //, it is implementation defined
120 	 *     whether steps (7) and (8) are skipped or processed.
121 	 *
122 	 * This case has already been handled, as part of steps (1) and (2).
123 	 */
124 
125 	/*
126 	 * (7) If there are any trailing slash characters in string, they
127 	 *     shall be removed.
128 	 */
129 	while (--p >= *argv)
130 		if (*p != '/')
131 			break;
132 	++p;
133 
134 	/*
135 	 * (8) If the remaining string is empty, string shall be set to
136 	 *     a single slash character.
137 	 */
138 	*p = '\0';
139 	(void)printf("%s\n", p == *argv ? "/" : *argv);
140 	exit(0);
141 }
142 
143 static void
144 usage()
145 {
146 	(void)fprintf(stderr, "usage: dirname path\n");
147 	exit(1);
148 }
149