写一个函数，算出两个文件的相对路径?

1. <?php
2. $a = '/a/b/c/d/e.php';
3. $b = '/a/b/12/34/c.php';
4. //获取path相对于conpath的相对路径
5. function sGetRelativePath($path, $conpath)
6. {
7. $pathArr = explode("/", $path);
8. $conpathArr = explode("/", $conpath);
9. $dismatchlen = 0;
10. for($i = 0; $i < count($pathArr); $i++)
11. {
12. if($conpathArr[$i] != $pathArr[$i])
13. {
14. $dismatchlen = count($pathArr) - $i;
15. $arrLeft = array_slice($pathArr, $i);
16. break;
17. }
18. }
19. $ret = str_repeat("../", $dismatchlen).implode("/", $arrLeft);
20. return $ret;
21. }
22. print_r(sGetRelativePath($b, $a));
23. ?>