private function _test_make_canonical()
{
$this->_check_equal('/a/b/c/', make_canonical('/a/b/c/'));
$this->_check_equal('/a/b/c/', make_canonical('/a/./b/c/'));
$this->_check_equal('/a/b/c/', make_canonical('/a/././b/c/'));
$this->_check_equal('a/b/c/', make_canonical('./a/b/c/'));
$this->_check_equal('a/b/c/', make_canonical('./a/./b/c/'));
$this->_check_equal('a/b/c/', make_canonical('./a/././b/c/'));
$this->_check_equal('a/b/c/', make_canonical('././a/b/c/'));
$this->_check_equal('a/b/c/', make_canonical('././a/./b/c/'));
$this->_check_equal('a/b/c/', make_canonical('././a/././b/c/'));
$this->_check_equal('/a/b/c/', make_canonical('/a/b/c/.'));
$this->_check_equal('/a/b/c/', make_canonical('/a/./b/c/.'));
$this->_check_equal('/a/b/c/', make_canonical('/a/././b/c/.'));
$this->_check_equal('a/b/c/', make_canonical('a/b/c/.'));
$this->_check_equal('a/b/c/', make_canonical('a/./b/c/.'));
$this->_check_equal('a/b/c/', make_canonical('a/././b/c/.'));
$this->_check_equal('a/b/c/', make_canonical('a/b/c/./.'));
$this->_check_equal('a/b/c/', make_canonical('a/./b/c/./.'));
$this->_check_equal('a/b/c/', make_canonical('a/././b/c/./.'));
}
/**
* Calculate a path between 'from' and 'to'.
* Both 'to' and 'from' should be absolute paths and are assumed to be on the
* same server. If the paths are the same, an empty string is returned (no path
* modification needed). If there is no common path, 'to' is returned. If 'from'
* is a sub-path of 'to', a chain of '..' directories is returned. If 'to' is a
* sub-path of 'from', 'from' is removed from the path in order to make it
* relative.
*
* <b>Examples:</b>
* <code>path_between ('/a/b/c/', '/a/b/c/') is ''
* path_between ('/a/b/c/', '/a/b/') is '../'
* path_between ('/a/b/c/', '/a/') is '../../'
* path_between ('/a/b/', '/a/b/c/') is 'c/'
* path_between ('/a/', '/a/b/c/') is 'b/c/'
* path_between ('/a/d/c', '/a/b/c/') is '/a/b/c/'
* </code>
*
* @param string $from
* @param string $to
* @param FILE_OPTIONS $opts
* @return string
*/
function path_between($from, $to, $opts = null)
{
if (!isset($opts)) {
$opts = global_file_options();
}
$from = make_canonical($from, $opts);
$to = make_canonical($to, $opts);
if (empty($to) || empty($from)) {
return $to;
}
$Result = $to;
if (strpos($from, $to) === 0) {
// target is subset of source
if (strlen($from) != strlen($to)) {
$Result = '';
$sub_url = substr($from, strlen($to));
$sub_folders = explode($opts->path_delimiter, $sub_url);
foreach ($sub_folders as $f) {
if ($f) {
$Result .= '..' . $opts->path_delimiter;
}
}
if ($Result == '') {
$Result = $opts->current_folder;
} elseif (ends_with_delimiter($Result, $opts) && !ends_with_delimiter($to)) {
$Result = substr($Result, 0, -1);
}
} else {
$Result = $opts->current_folder . $opts->path_delimiter;
}
} else {
if (strpos($to, $from) === 0) {
// source is subset of target
$Result = substr($to, strlen($from));
if (strlen($Result) > 1 && $Result[0] == $opts->path_delimiter) {
$Result = substr($Result, 1);
} elseif ($Result == $opts->path_delimiter) {
$Result = $opts->current_folder . $opts->path_delimiter;
}
} elseif ($from[0] == $to[0] && $from[0] == $opts->path_delimiter) {
// check for partial containment of rooted paths
$to_folders = explode($opts->path_delimiter, trim($to, $opts->path_delimiter));
$from_folders = explode($opts->path_delimiter, trim($from, $opts->path_delimiter));
$common_root_folder_count = 0;
$count = min(array(sizeof($to_folders), sizeof($from_folders)));
for ($index = 0; $index < $count; $index += 1) {
if ($from_folders[$index] != '') {
if ($to_folders[$index] == $from_folders[$index]) {
$common_root_folder_count += 1;
} else {
break;
}
}
}
if ($common_root_folder_count > 0) {
$leader = str_repeat('..' . $opts->path_delimiter, sizeof($from_folders) - $common_root_folder_count);
$Result = $leader . join($opts->path_delimiter, array_slice($to_folders, $common_root_folder_count));
if (ends_with_delimiter($to, $opts)) {
$Result .= $opts->path_delimiter;
}
}
}
}
return $Result;
}
