File put contents fails if you try to put a file in a directory that doesn't exist. This creates the directory.

<?php
    function file_force_contents($dir, $contents){
        $parts = explode('/', $dir);
        $file = array_pop($parts);
        $dir = '';
        foreach($parts as $part)
            if(!is_dir($dir .= "/$part")) mkdir($dir);
        file_put_contents("$dir/$file", $contents);
    }
?>