basename.c revision 24360 
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[] = "@(#)basename.c	8.4 (Berkeley) 5/4/95";
42#endif /* not lint */
43
44#include <stdio.h>
45#include <stdlib.h>
46#include <string.h>
47#include <unistd.h>
48
49void usage __P((void));
50
51int
52main(argc, argv)
53	int argc;
54	char **argv;
55{
56	char *p;
57	int ch;
58
59	while ((ch = getopt(argc, argv, "")) != -1)
60		switch(ch) {
61		case '?':
62		default:
63			usage();
64		}
65	argc -= optind;
66	argv += optind;
67
68	if (argc != 1 && argc != 2)
69		usage();
70
71	/*
72	 * (1) If string is // it is implementation defined whether steps (2)
73	 *     through (5) are skipped or processed.
74	 *
75	 * (2) If string consists entirely of slash characters, string shall
76	 *     be set to a single slash character.  In this case, skip steps
77	 *     (3) through (5).
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		continue;
97	while (*--p == '/')
98		continue;
99	*++p = '\0';
100
101	/*
102	 * (4) If there are any slash characters remaining in string, the
103	 *     prefix of string up to an including the last slash character
104	 *     in string shall be removed.
105	 */
106	while (--p >= *argv)
107		if (*p == '/')
108			break;
109	++p;
110
111	/*
112	 * (5) If the suffix operand is present, is not identical to the
113	 *     characters remaining in string, and is identical to a suffix
114	 *     of the characters remaining in string, the suffix suffix
115	 *     shall be removed from string.
116	 */
117	if (*++argv) {
118		int suffixlen, stringlen, off;
119
120		suffixlen = strlen(*argv);
121		stringlen = strlen(p);
122
123		if (suffixlen < stringlen) {
124			off = stringlen - suffixlen;
125			if (!strcmp(p + off, *argv))
126				p[off] = '\0';
127		}
128	}
129	(void)printf("%s\n", p);
130	exit(0);
131}
132
133void
134usage()
135{
136
137	(void)fprintf(stderr, "usage: basename string [suffix]\n");
138	exit(1);
139}
140