Getting relative path from absolute path in PHP

Question

I noticed some similar questions about this problem when I typed the title, but they seem not be in PHP. So what's the solution to it with a PHP function?

To be specified.

$a="/home/apache/a/a.php"; $b="/home/root/b/b.php"; $relpath = getRelativePath($a,$b); //needed function,should return '../../root/b/b.php' 

Any good ideas? Thanks.

Answer 1

Try this one:

function getRelativePath($from, $to) {     // some compatibility fixes for Windows paths     $from = is_dir($from) ? rtrim($from, '\/') . '/' : $from;     $to   = is_dir($to)   ? rtrim($to, '\/') . '/'   : $to;     $from = str_replace('\\', '/', $from);     $to   = str_replace('\\', '/', $to);      $from     = explode('/', $from);     $to       = explode('/', $to);     $relPath  = $to;      foreach($from as $depth => $dir) {         // find first non-matching dir         if($dir === $to[$depth]) {             // ignore this directory             array_shift($relPath);         } else {             // get number of remaining dirs to $from             $remaining = count($from) - $depth;             if($remaining > 1) {                 // add traversals up to first matching dir                 $padLength = (count($relPath) + $remaining - 1) * -1;                 $relPath = array_pad($relPath, $padLength, '..');                 break;             } else {                 $relPath[0] = './' . $relPath[0];             }         }     }     return implode('/', $relPath); } 

This will give

$a="/home/a.php"; $b="/home/root/b/b.php"; echo getRelativePath($a,$b), PHP_EOL;  // ./root/b/b.php 

and

$a="/home/apache/a/a.php"; $b="/home/root/b/b.php"; echo getRelativePath($a,$b), PHP_EOL; // ../../root/b/b.php 

and

$a="/home/root/a/a.php"; $b="/home/apache/htdocs/b/en/b.php"; echo getRelativePath($a,$b), PHP_EOL; // ../../apache/htdocs/b/en/b.php 

and

$a="/home/apache/htdocs/b/en/b.php"; $b="/home/root/a/a.php"; echo getRelativePath($a,$b), PHP_EOL; // ../../../../root/a/a.php