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 * Glenn Fowler 25 * AT&T Bell Laboratories 26 * 27 * return path to file a/b with access mode using : separated dirs 28 * both a and b may be 0 29 * if a==".." then relative paths in dirs are ignored 30 * if (mode&PATH_REGULAR) then path must not be a directory 31 * if (mode&PATH_ABSOLUTE) then path must be rooted 32 * path returned in path buffer 33 */ 34 35 #include <ast.h> 36 37 char* 38 pathaccess(register char* path, register const char* dirs, const char* a, const char* b, register int mode) 39 { 40 int sib = a && a[0] == '.' && a[1] == '.' && a[2] == 0; 41 int sep = ':'; 42 char cwd[PATH_MAX]; 43 44 do 45 { 46 dirs = pathcat(path, dirs, sep, a, b); 47 pathcanon(path, 0); 48 if ((!sib || *path == '/') && pathexists(path, mode)) 49 { 50 if (*path == '/' || !(mode & PATH_ABSOLUTE)) 51 return path; 52 dirs = getcwd(cwd, sizeof(cwd)); 53 sep = 0; 54 } 55 } while (dirs); 56 return 0; 57 } 58