1 /*
2 * Compute the relative path needed to go from one Unix dir to another
3 *
4 * Copyright 2006 Alexandre Julliard
5 *
6 * This library is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU Lesser General Public
8 * License as published by the Free Software Foundation; either
9 * version 2.1 of the License, or (at your option) any later version.
10 *
11 * This library is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 * Lesser General Public License for more details.
15 *
16 * You should have received a copy of the GNU Lesser General Public
17 * License along with this library; if not, write to the Free Software
18 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
19 */
20
21 #include "config.h"
22
23 #include <stdio.h>
24 #include <stdlib.h>
25 #include <string.h>
26
27 /* determine where the destination path is located relative to the 'from' path */
28 static const char *get_relative_path( const char *from, const char *dest, unsigned int *dotdots )
29 {
30 #define DIR_END(p) (*(p) == 0 || *(p) == '/')
31 const char *start;
32
33 /* a path of "." is equivalent to an empty path */
34 if (!strcmp( from, "." )) from = "";
35
36 *dotdots = 0;
37 for (;;)
38 {
39 while (*from == '/') from++;
40 while (*dest == '/') dest++;
41 start = dest; /* save start of next path element */
42 if (!*from) break;
43
44 while (!DIR_END(from) && *from == *dest) { from++; dest++; }
45 if (DIR_END(from) && DIR_END(dest)) continue;
46
47 /* count remaining elements in 'from' */
48 do
49 {
50 (*dotdots)++;
51 while (!DIR_END(from)) from++;
52 while (*from == '/') from++;
53 }
54 while (*from);
55 break;
56 }
57 return start;
58 #undef DIR_END
59 }
60
61
62 int main( int argc, char *argv[] )
63 {
64 const char *start;
65 unsigned int dotdots = 0;
66
67 if (argc != 3)
68 {
69 fprintf( stderr, "Usage: %s fromdir todir\n", argv[0] );
70 exit(1);
71 }
72 start = get_relative_path( argv[1], argv[2], &dotdots );
73
74 if (!start[0] && !dotdots) printf( ".\n" );
75 else
76 {
77 while (dotdots)
78 {
79 printf( ".." );
80 dotdots--;
81 if (dotdots || start[0]) printf( "/" );
82 }
83 printf( "%s\n", start );
84 }
85 exit(0);
86 }
87
This page was automatically generated by the
LXR engine.
Visit the LXR main site for more
information.