dirname.c revision 1590 
1/*-
2 * Copyright (c) 1991, 1993, 1994
3 *	The Regents of the University of California.  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
35static char copyright[] =
36"@(#) Copyright (c) 1991, 1993, 1994\n\
37	The Regents of the University of California.  All rights reserved.\n";
38#endif /* not lint */
39
40#ifndef lint
41static char sccsid[] = "@(#)dirname.c	8.3 (Berkeley) 4/2/94";
42#endif /* not lint */
43
44#include <stdio.h>
45#include <stdlib.h>
46
47void usage __P((void));
48
49int
50main(argc, argv)
51	int argc;
52	char **argv;
53{
54	char *p;
55	int ch;
56
57	while ((ch = getopt(argc, argv, "")) != EOF)
58		switch(ch) {
59		case '?':
60		default:
61			usage();
62		}
63	argc -= optind;
64	argv += optind;
65
66	if (argc != 1)
67		usage();
68
69	/*
70	 * (1) If string is //, skip steps (2) through (5).
71	 * (2) If string consists entirely of slash characters, string
72	 *     shall be set to a single slash character.  In this case,
73	 *     skip steps (3) through (8).
74	 */
75	for (p = *argv;; ++p) {
76		if (!*p) {
77			if (p > *argv)
78				(void)printf("/\n");
79			else
80				(void)printf(".\n");
81			exit(0);
82		}
83		if (*p != '/')
84			break;
85	}
86
87	/*
88	 * (3) If there are any trailing slash characters in string, they
89	 *     shall be removed.
90	 */
91	for (; *p; ++p);
92	while (*--p == '/')
93		continue;
94	*++p = '\0';
95
96	/*
97	 * (4) If there are no slash characters remaining in string,
98	 *     string shall be set to a single period character.  In this
99	 *     case skip steps (5) through (8).
100	 *
101	 * (5) If there are any trailing nonslash characters in string,
102	 *     they shall be removed.
103	 */
104	while (--p >= *argv)
105		if (*p == '/')
106			break;
107	++p;
108	if (p == *argv) {
109		(void)printf(".\n");
110		exit(0);
111	}
112
113	/*
114	 * (6) If the remaining string is //, it is implementation defined
115	 *     whether steps (7) and (8) are skipped or processed.
116	 *
117	 * This case has already been handled, as part of steps (1) and (2).
118	 */
119
120	/*
121	 * (7) If there are any trailing slash characters in string, they
122	 *     shall be removed.
123	 */
124	while (--p >= *argv)
125		if (*p != '/')
126			break;
127	++p;
128
129	/*
130	 * (8) If the remaining string is empty, string shall be set to
131	 *     a single slash character.
132	 */
133	*p = '\0';
134	(void)printf("%s\n", p == *argv ? "/" : *argv);
135	exit(0);
136}
137
138void
139usage()
140{
141
142	(void)fprintf(stderr, "usage: dirname path\n");
143	exit(1);
144}
145