PHP: Extract direct sub directory from path string
- by Nebs
I need to extract the name of the direct sub directory from a full path string.
For example, say we have:
$str = "dir1/dir2/dir3/dir4/filename.ext";
$dir = "dir1/dir2";
Then the name of the sub-directory in the $str path relative to $dir would be "dir3". Note that $dir never has '/' at the ends.
So the function should be:
$subdir = getsubdir($str,$dir);
echo $subdir; // Outputs "dir3"
If $dir="dir1" then the output would be "dir2". If $dir="dir1/dir2/dir3/dir4" then the output would be "" (empty). If $dir="" then the output would be "dir1". Etc..
Currently this is what I have, and it works (as far as I've tested it). I'm just wondering if there's a simpler way since I find I'm using a lot of string functions. Maybe there's some magic regexp to do this in one line? (I'm not too good with regexp unfortunately).
function getsubdir($str,$dir) {
// Remove the filename
$str = dirname($str);
// Remove the $dir
if(!empty($dir)){
$str = str_replace($dir,"",$str);
}
// Remove the leading '/' if there is one
$si = stripos($str,"/");
if($si == 0){
$str = substr($str,1);
}
// Remove everything after the subdir (if there is anything)
$lastpart = strchr($str,"/");
$str = str_replace($lastpart,"",$str);
return $str;
}
As you can see, it's a little hacky in order to handle some odd cases (no '/' in input, empty input, etc). I hope all that made sense. Any help/suggestions are welcome.
