dirname.c revision 41568 
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 const 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 const char sccsid[] = "@(#)dirname.c	8.4 (Berkeley) 5/4/95";
42#endif /* not lint */
43
44#include <stdio.h>
45#include <stdlib.h>
46#include <unistd.h>
47
48void usage __P((void));
49
50int
51main(argc, argv)
52	int argc;
53	char **argv;
54{
55	char *p;
56	int ch;
57
58	while ((ch = getopt(argc, argv, "")) != -1)
59		switch(ch) {
60		case '?':
61		default:
62			usage();
63		}
64	argc -= optind;
65	argv += optind;
66
67	if (argc != 1)
68		usage();
69
70	/*
71	 * (1) If string is //, skip steps (2) through (5).
72	 * (2) If string consists entirely of slash characters, string
73	 *     shall be set to a single slash character.  In this case,
74	 *     skip steps (3) through (8).
75	 */
76	for (p = *argv;; ++p) {
77		if (!*p) {
78			if (p > *argv)
79				(void)printf("/\n");
80			else
81				(void)printf(".\n");
82			exit(0);
83		}
84		if (*p != '/')
85			break;
86	}
87
88	/*
89	 * (3) If there are any trailing slash characters in string, they
90	 *     shall be removed.
91	 */
92	for (; *p; ++p);
93	while (*--p == '/')
94		continue;
95	*++p = '\0';
96
97	/*
98	 * (4) If there are no slash characters remaining in string,
99	 *     string shall be set to a single period character.  In this
100	 *     case skip steps (5) through (8).
101	 *
102	 * (5) If there are any trailing nonslash characters in string,
103	 *     they shall be removed.
104	 */
105	while (--p >= *argv)
106		if (*p == '/')
107			break;
108	++p;
109	if (p == *argv) {
110		(void)printf(".\n");
111		exit(0);
112	}
113
114	/*
115	 * (6) If the remaining string is //, it is implementation defined
116	 *     whether steps (7) and (8) are skipped or processed.
117	 *
118	 * This case has already been handled, as part of steps (1) and (2).
119	 */
120
121	/*
122	 * (7) If there are any trailing slash characters in string, they
123	 *     shall be removed.
124	 */
125	while (--p >= *argv)
126		if (*p != '/')
127			break;
128	++p;
129
130	/*
131	 * (8) If the remaining string is empty, string shall be set to
132	 *     a single slash character.
133	 */
134	*p = '\0';
135	(void)printf("%s\n", p == *argv ? "/" : *argv);
136	exit(0);
137}
138
139void
140usage()
141{
142
143	(void)fprintf(stderr, "usage: dirname path\n");
144	exit(1);
145}
146