basename.c revision 1.2 
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
35char 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: @(#)basename.c	5.1 (Berkeley) 3/9/91";*/
42static char rcsid[] = "$Id: basename.c,v 1.2 1993/08/01 18:18:23 mycroft Exp $";
43#endif /* not lint */
44
45#include <stdio.h>
46#include <stdlib.h>
47#include <string.h>
48
49main(argc, argv)
50	int argc;
51	char **argv;
52{
53	extern int optind;
54	register 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 && argc != 2)
67		usage();
68
69	/*
70	 * (1) If string is // it is implementation defined whether steps (2)
71	 *     through (5) are skipped or processed.
72	 *
73	 * (2) If string consists entirely of slash characters, string shall
74	 *     be set to a single slash character.  In this case, skip steps
75	 *     (3) through (5).
76	 */
77	for (p = *argv;; ++p) {
78		if (!*p) {
79			if (p > *argv)
80				(void)printf("/\n");
81			else
82				(void)printf("\n");
83			exit(0);
84		}
85		if (*p != '/')
86			break;
87	}
88
89	/*
90	 * (3) If there are any trailing slash characters in string, they
91	 *     shall be removed.
92	 */
93	for (; *p; ++p);
94	while (*--p == '/');
95	*++p = '\0';
96
97	/*
98	 * (4) If there are any slash characters remaining in string, the
99	 *     prefix of string up to an including the last slash character
100	 *     in string shall be removed.
101	 */
102	while (--p >= *argv)
103		if (*p == '/')
104			break;
105	++p;
106
107	/*
108	 * (5) If the suffix operand is present, is not identical to the
109	 *     characters remaining in string, and is identical to a suffix
110	 *     of the characters remaining in string, the suffix suffix
111	 *     shall be removed from string.
112	 */
113	if (*++argv) {
114		int suffixlen, stringlen, off;
115
116		suffixlen = strlen(*argv);
117		stringlen = strlen(p);
118
119		if (suffixlen < stringlen) {
120			off = stringlen - suffixlen;
121			if (!strcmp(p + off, *argv))
122				p[off] = '\0';
123		}
124	}
125	(void)printf("%s\n", p);
126	exit(0);
127}
128
129usage()
130{
131	(void)fprintf(stderr, "usage: basename string [suffix]\n");
132	exit(1);
133}
134