xref: /onnv-gate/usr/src/lib/libast/common/comp/dirname.c (revision 12068:08a39a083754)
14887Schin /***********************************************************************
24887Schin *                                                                      *
34887Schin *               This software is part of the ast package               *
4*12068SRoger.Faulkner@Oracle.COM *          Copyright (c) 1985-2010 AT&T Intellectual Property          *
54887Schin *                      and is licensed under the                       *
64887Schin *                  Common Public License, Version 1.0                  *
78462SApril.Chin@Sun.COM *                    by AT&T Intellectual Property                     *
84887Schin *                                                                      *
94887Schin *                A copy of the License is available at                 *
104887Schin *            http://www.opensource.org/licenses/cpl1.0.txt             *
114887Schin *         (with md5 checksum 059e8cd6165cb4c31e351f2b69388fd9)         *
124887Schin *                                                                      *
134887Schin *              Information and Software Systems Research               *
144887Schin *                            AT&T Research                             *
154887Schin *                           Florham Park NJ                            *
164887Schin *                                                                      *
174887Schin *                 Glenn Fowler <gsf@research.att.com>                  *
184887Schin *                  David Korn <dgk@research.att.com>                   *
194887Schin *                   Phong Vo <kpv@research.att.com>                    *
204887Schin *                                                                      *
214887Schin ***********************************************************************/
224887Schin #pragma prototyped
234887Schin /*
244887Schin  * dirname(3) implementation
254887Schin  */
264887Schin 
274887Schin #include <ast_std.h>
284887Schin 
294887Schin #if defined(__EXPORT__)
304887Schin #define extern	__EXPORT__
314887Schin #endif
324887Schin 
dirname(register char * pathname)334887Schin extern char *dirname(register char *pathname)
344887Schin {
354887Schin 	register char  *last;
364887Schin 	/* go to end of path */
374887Schin 	for(last=pathname; *last; last++);
384887Schin 	/* back over trailing '/' */
394887Schin 	while(last>pathname && *--last=='/');
404887Schin 	/* back over non-slash chars */
414887Schin 	for(;last>pathname && *last!='/';last--);
424887Schin 	if(last==pathname)
434887Schin 	{
444887Schin 		/* all '/' or "" */
454887Schin 		if(*last!='/')
464887Schin 			*last = '.';
474887Schin 		/* preserve // */
484887Schin 		else if(last[1]=='/')
494887Schin 			last++;
504887Schin 	}
514887Schin 	else
524887Schin 	{
534887Schin 		/* back over trailing '/' */
544887Schin 		for(;*last=='/' && last > pathname; last--);
554887Schin 		/* preserve // */
564887Schin 		if(last==pathname && *pathname=='/' && pathname[1]=='/')
574887Schin 			last++;
584887Schin 	}
594887Schin 	*(last + 1) = 0;
604887Schin 	return(pathname);
614887Schin }
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