1 /***********************************************************************
2 * *
3 * This software is part of the ast package *
4 * Copyright (c) 1985-2010 AT&T Intellectual Property *
5 * and is licensed under the *
6 * Common Public License, Version 1.0 *
7 * by AT&T Intellectual Property *
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*
pathaccess(register char * path,register const char * dirs,const char * a,const char * b,register int mode)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