1 /*********************************************************************** 2 * * 3 * This software is part of the ast package * 4 * Copyright (c) 1985-2007 AT&T Knowledge Ventures * 5 * and is licensed under the * 6 * Common Public License, Version 1.0 * 7 * by AT&T Knowledge Ventures * 8 * * 9 * A copy of the License is available at * 10 * http://www.opensource.org/licenses/cpl1.0.txt * 11 * (with md5 checksum 059e8cd6165cb4c31e351f2b69388fd9) * 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 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