basename.c revision 1.1 
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
41static char sccsid[] = "@(#)basename.c	5.1 (Berkeley) 3/9/91";
42#endif /* not lint */
43
44#include <stdio.h>
45#include <stdlib.h>
46#include <string.h>
47
48main(argc, argv)
49	int argc;
50	char **argv;
51{
52	extern int optind;
53	register char *p;
54	int ch;
55
56	while ((ch = getopt(argc, argv, "")) != EOF)
57		switch(ch) {
58		case '?':
59		default:
60			usage();
61		}
62	argc -= optind;
63	argv += optind;
64
65	if (argc != 1 && argc != 2)
66		usage();
67
68	/*
69	 * (1) If string is // it is implementation defined whether steps (2)
70	 *     through (5) are skipped or processed.
71	 *
72	 * (2) If string consists entirely of slash characters, string shall
73	 *     be set to a single slash character.  In this case, skip steps
74	 *     (3) through (5).
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	*++p = '\0';
95
96	/*
97	 * (4) If there are any slash characters remaining in string, the
98	 *     prefix of string up to an including the last slash character
99	 *     in string shall be removed.
100	 */
101	while (--p >= *argv)
102		if (*p == '/')
103			break;
104	++p;
105
106	/*
107	 * (5) If the suffix operand is present, is not identical to the
108	 *     characters remaining in string, and is identical to a suffix
109	 *     of the characters remaining in string, the suffix suffix
110	 *     shall be removed from string.
111	 */
112	if (*++argv) {
113		int suffixlen, stringlen, off;
114
115		suffixlen = strlen(*argv);
116		stringlen = strlen(p);
117
118		if (suffixlen < stringlen) {
119			off = stringlen - suffixlen;
120			if (!strcmp(p + off, *argv))
121				p[off] = '\0';
122		}
123	}
124	(void)printf("%s\n", p);
125	exit(0);
126}
127
128usage()
129{
130	(void)fprintf(stderr, "usage: basename string [suffix]\n");
131	exit(1);
132}
133