Home | History | Annotate | Line # | Download | only in dirname
dirname.c revision 1.1.1.1 
      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
     35 char 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[] = "@(#)dirname.c	5.6 (Berkeley) 3/9/91";
     42 #endif /* not lint */
     43 
     44 #include <stdio.h>
     45 #include <stdlib.h>
     46 
     47 main(argc, argv)
     48 	int argc;
     49 	char **argv;
     50 {
     51 	extern int optind;
     52 	register char *p;
     53 	int ch;
     54 
     55 	while ((ch = getopt(argc, argv, "")) != EOF)
     56 		switch(ch) {
     57 		case '?':
     58 		default:
     59 			usage();
     60 		}
     61 	argc -= optind;
     62 	argv += optind;
     63 
     64 	if (argc != 1)
     65 		usage();
     66 
     67 	/*
     68 	 * (1) If string is //, skip steps (2) through (5).
     69 	 * (2) If string consists entirely of slash characters, string
     70 	 *     shall be set to a single slash character.  In this case,
     71 	 *     skip steps (3) through (8).
     72 	 */
     73 	for (p = *argv;; ++p) {
     74 		if (!*p) {
     75 			if (p > *argv)
     76 				(void)printf("/\n");
     77 			else
     78 				(void)printf(".\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 	while (*--p == '/');
     91 	*++p = '\0';
     92 
     93 	/*
     94 	 * (4) If there are no slash characters remaining in string,
     95 	 *     string shall be set to a single period character.  In this
     96 	 *     case skip steps (5) through (8).
     97 	 *
     98 	 * (5) If there are any trailing nonslash characters in string,
     99 	 *     they shall be removed.
    100 	 */
    101 	while (--p >= *argv)
    102 		if (*p == '/')
    103 			break;
    104 	++p;
    105 	if (p == *argv) {
    106 		(void)printf(".\n");
    107 		exit(0);
    108 	}
    109 
    110 	/*
    111 	 * (6) If the remaining string is //, it is implementation defined
    112 	 *     whether steps (7) and (8) are skipped or processed.
    113 	 *
    114 	 * This case has already been handled, as part of steps (1) and (2).
    115 	 */
    116 
    117 	/*
    118 	 * (7) If there are any trailing slash characters in string, they
    119 	 *     shall be removed.
    120 	 */
    121 	while (--p >= *argv)
    122 		if (*p != '/')
    123 			break;
    124 	++p;
    125 
    126 	/*
    127 	 * (8) If the remaining string is empty, string shall be set to
    128 	 *     a single slash character.
    129 	 */
    130 	*p = '\0';
    131 	(void)printf("%s\n", p == *argv ? "/" : *argv);
    132 	exit(0);
    133 }
    134 
    135 usage()
    136 {
    137 	(void)fprintf(stderr, "usage: dirname path\n");
    138 	exit(1);
    139 }
    140