xref: /openbsd-src/usr.bin/basename/basename.c (revision b2ea75c1b17e1a9a339660e7ed45cd24946b230e)
1 /*	$OpenBSD: basename.c,v 1.3 1997/08/17 21:25:01 millert 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. All advertising materials mentioning features or use of this software
17  *    must display the following acknowledgement:
18  *	This product includes software developed by the University of
19  *	California, Berkeley and its contributors.
20  * 4. Neither the name of the University nor the names of its contributors
21  *    may be used to endorse or promote products derived from this software
22  *    without specific prior written permission.
23  *
24  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
25  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
28  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
29  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
30  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
31  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
32  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
33  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34  * SUCH DAMAGE.
35  */
36 
37 #ifndef lint
38 static char copyright[] =
39 "@(#) Copyright (c) 1991, 1993, 1994\n\
40 	The Regents of the University of California.  All rights reserved.\n";
41 #endif /* not lint */
42 
43 #ifndef lint
44 #if 0
45 static char sccsid[] = "@(#)basename.c	8.4 (Berkeley) 5/4/95";
46 #endif
47 static char rcsid[] = "$OpenBSD: basename.c,v 1.3 1997/08/17 21:25:01 millert Exp $";
48 #endif /* not lint */
49 
50 #include <stdio.h>
51 #include <stdlib.h>
52 #include <string.h>
53 #include <locale.h>
54 #include <unistd.h>
55 
56 void usage __P((void));
57 
58 int
59 main(argc, argv)
60 	int argc;
61 	char **argv;
62 {
63 	char *p;
64 
65 	setlocale(LC_ALL, "");
66 
67 	if (argc != 2 && argc != 3)
68 		usage();
69 	argc--;
70 	argv++;
71 
72 	/*
73 	 * (1) If string is // it is implementation defined whether steps (2)
74 	 *     through (5) are skipped or processed.
75 	 *
76 	 * (2) If string consists entirely of slash characters, string shall
77 	 *     be set to a single slash character.  In this case, skip steps
78 	 *     (3) through (5).
79 	 */
80 	for (p = *argv;; ++p) {
81 		if (!*p) {
82 			if (p > *argv)
83 				(void)putchar('/');
84 			(void)putchar('\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)puts(p);
130 	exit(0);
131 }
132 
133 void
134 usage()
135 {
136 
137 	(void)fprintf(stderr, "usage: basename string [suffix]\n");
138 	exit(1);
139 }
140