Alexandre Julliard | 35842ca | 2006-02-17 11:42:17 +0100 | [diff] [blame] | 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 |
Jonathan Ernst | 360a3f9 | 2006-05-18 14:49:52 +0200 | [diff] [blame^] | 18 | * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA |
Alexandre Julliard | 35842ca | 2006-02-17 11:42:17 +0100 | [diff] [blame] | 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 | *dotdots = 0; |
| 34 | for (;;) |
| 35 | { |
| 36 | while (*from == '/') from++; |
| 37 | while (*dest == '/') dest++; |
| 38 | start = dest; /* save start of next path element */ |
| 39 | if (!*from) break; |
| 40 | |
| 41 | while (!DIR_END(from) && *from == *dest) { from++; dest++; } |
| 42 | if (DIR_END(from) && DIR_END(dest)) continue; |
| 43 | |
| 44 | /* count remaining elements in 'from' */ |
| 45 | do |
| 46 | { |
| 47 | (*dotdots)++; |
| 48 | while (!DIR_END(from)) from++; |
| 49 | while (*from == '/') from++; |
| 50 | } |
| 51 | while (*from); |
| 52 | break; |
| 53 | } |
| 54 | return start; |
| 55 | #undef DIR_END |
| 56 | } |
| 57 | |
| 58 | |
| 59 | int main( int argc, char *argv[] ) |
| 60 | { |
| 61 | const char *start; |
| 62 | unsigned int dotdots = 0; |
| 63 | |
| 64 | if (argc != 3) |
| 65 | { |
| 66 | fprintf( stderr, "Usage: %s fromdir todir\n", argv[0] ); |
| 67 | exit(1); |
| 68 | } |
| 69 | start = get_relative_path( argv[1], argv[2], &dotdots ); |
| 70 | |
| 71 | if (!start[0] && !dotdots) printf( ".\n" ); |
| 72 | else |
| 73 | { |
| 74 | while (dotdots) |
| 75 | { |
| 76 | printf( ".." ); |
| 77 | dotdots--; |
| 78 | if (dotdots || start[0]) printf( "/" ); |
| 79 | } |
| 80 | printf( "%s\n", start ); |
| 81 | } |
| 82 | exit(0); |
| 83 | } |