1 /***********************************************************************
2 *                                                                      *
3 *               This software is part of the ast package               *
4 *          Copyright (c) 1985-2011 AT&T Intellectual Property          *
5 *                      and is licensed under the                       *
6 *                 Eclipse Public License, Version 1.0                  *
7 *                    by AT&T Intellectual Property                     *
8 *                                                                      *
9 *                A copy of the License is available at                 *
10 *          http://www.eclipse.org/org/documents/epl-v10.html           *
11 *         (with md5 checksum b35adb5213ca9657e911e9befb180842)         *
12 *                                                                      *
13 *              Information and Software Systems Research               *
14 *                            AT&T Research                             *
15 *                           Florham Park NJ                            *
16 *                                                                      *
17 *                 Glenn Fowler <gsf@research.att.com>                  *
18 *                  David Korn <dgk@research.att.com>                   *
19 *                   Phong Vo <kpv@research.att.com>                    *
20 *                                                                      *
21 ***********************************************************************/
22 #pragma prototyped
23 /*
24  * dirname(3) implementation
25  */
26 
27 #include <ast_std.h>
28 
29 #if defined(__EXPORT__)
30 #define extern	__EXPORT__
31 #endif
32 
dirname(register char * pathname)33 extern char *dirname(register char *pathname)
34 {
35 	register char  *last;
36 	/* go to end of path */
37 	for(last=pathname; *last; last++);
38 	/* back over trailing '/' */
39 	while(last>pathname && *--last=='/');
40 	/* back over non-slash chars */
41 	for(;last>pathname && *last!='/';last--);
42 	if(last==pathname)
43 	{
44 		/* all '/' or "" */
45 		if(*last!='/')
46 			*last = '.';
47 		/* preserve // */
48 		else if(last[1]=='/')
49 			last++;
50 	}
51 	else
52 	{
53 		/* back over trailing '/' */
54 		for(;*last=='/' && last > pathname; last--);
55 		/* preserve // */
56 		if(last==pathname && *pathname=='/' && pathname[1]=='/')
57 			last++;
58 	}
59 	*(last + 1) = 0;
60 	return(pathname);
61 }
62