xref: /openbsd/usr.bin/basename/basename.c (revision db3296cf)
1 /*	$OpenBSD: basename.c,v 1.6 2003/06/10 22:20:44 deraadt Exp $	*/
2 /*	$NetBSD: basename.c,v 1.9 1995/09/02 05:29:46 jtc Exp $	*/
3 
4 /*-
5  * Copyright (c) 1991, 1993, 1994
6  *	The Regents of the University of California.  All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  * 3. Neither the name of the University nor the names of its contributors
17  *    may be used to endorse or promote products derived from this software
18  *    without specific prior written permission.
19  *
20  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30  * SUCH DAMAGE.
31  */
32 
33 #ifndef lint
34 static char copyright[] =
35 "@(#) Copyright (c) 1991, 1993, 1994\n\
36 	The Regents of the University of California.  All rights reserved.\n";
37 #endif /* not lint */
38 
39 #ifndef lint
40 #if 0
41 static char sccsid[] = "@(#)basename.c	8.4 (Berkeley) 5/4/95";
42 #endif
43 static char rcsid[] = "$OpenBSD: basename.c,v 1.6 2003/06/10 22:20:44 deraadt Exp $";
44 #endif /* not lint */
45 
46 #include <stdio.h>
47 #include <stdlib.h>
48 #include <string.h>
49 #include <locale.h>
50 #include <unistd.h>
51 
52 void usage(void);
53 
54 int
55 main(int argc, char *argv[])
56 {
57 	char *p;
58 
59 	setlocale(LC_ALL, "");
60 
61 	if (argc != 2 && argc != 3)
62 		usage();
63 	argc--;
64 	argv++;
65 
66 	/*
67 	 * (1) If string is // it is implementation defined whether steps (2)
68 	 *     through (5) are skipped or processed.
69 	 *
70 	 * (2) If string consists entirely of slash characters, string shall
71 	 *     be set to a single slash character.  In this case, skip steps
72 	 *     (3) through (5).
73 	 */
74 	for (p = *argv;; ++p) {
75 		if (!*p) {
76 			if (p > *argv)
77 				(void)putchar('/');
78 			(void)putchar('\n');
79 			exit(0);
80 		}
81 		if (*p != '/')
82 			break;
83 	}
84 
85 	/*
86 	 * (3) If there are any trailing slash characters in string, they
87 	 *     shall be removed.
88 	 */
89 	for (; *p; ++p)
90 		continue;
91 	while (*--p == '/')
92 		continue;
93 	*++p = '\0';
94 
95 	/*
96 	 * (4) If there are any slash characters remaining in string, the
97 	 *     prefix of string up to an including the last slash character
98 	 *     in string shall be removed.
99 	 */
100 	while (--p >= *argv)
101 		if (*p == '/')
102 			break;
103 	++p;
104 
105 	/*
106 	 * (5) If the suffix operand is present, is not identical to the
107 	 *     characters remaining in string, and is identical to a suffix
108 	 *     of the characters remaining in string, the suffix suffix
109 	 *     shall be removed from string.
110 	 */
111 	if (*++argv) {
112 		int suffixlen, stringlen, off;
113 
114 		suffixlen = strlen(*argv);
115 		stringlen = strlen(p);
116 
117 		if (suffixlen < stringlen) {
118 			off = stringlen - suffixlen;
119 			if (!strcmp(p + off, *argv))
120 				p[off] = '\0';
121 		}
122 	}
123 	(void)puts(p);
124 	exit(0);
125 }
126 
127 void
128 usage(void)
129 {
130 
131 	(void)fprintf(stderr, "usage: basename string [suffix]\n");
132 	exit(1);
133 }
134