PHP: How to Compare Directory Attributes & all files within

I wrote this function today to compare the contents of two folders or directories based on 3 comparison points:

• Do files exist in both directories?
• Were they both modified at the same time?
• Are the contents identical?

This function returns a 3D array containing a list of all differences between the contents of the two directories...

Please see right hand column before copying >

//SAMPLE USAGE:
print_r(returnDirDifferences("folder/subfolder","folder2/subfolder2/other");


function returnDirDifferences($dir1, $dir2='.'){
 if(!$dir1){return(false);}
 $ignore = array('.', '..');
 $returnarray=array();
 $dh = @opendir($dir1);
 while(false !== ($file = readdir($dh))){ // Loop through the directory
  if(!in_array($file, $ignore)){
   if(is_dir("$dir1/$file")){
    if(is_dir("$dir2/$file")){// Its a directory, so keep reading down:
     $tempresults = returnDirDifferences("$dir1/$file","$dir2/$file");
     if($tempresults[0]){
      $returnarray = array_merge($returnarray,$tempresults);
     }
    }else{
     array_push($returnarray,array('path1'=>"$dir1/$file",'path2'=>0,'status'=>"non-existing"));
    }
   } else {
    $tempresults = returnFileDifferences("$dir1/$file","$dir2/$file");
    if($tempresults){array_push($returnarray,$tempresults);}
   }
  }
 }
 closedir($dh);
 //return 3D array of differences or false if there are none:
 if($returnarray[0]){return($returnarray);}else{return(false);}
}
function returnFileDifferences($path1,$path2){
  $path1=(file_exists($path1) ? $path1 : 0);
  $path2=(file_exists($path2) ? $path2 : 0);
  if(!$path1 || !$path2){//check existance:
     return array('path1'=>$path1,'path2'=>$path2,'status'=>'non-existing');
  }else if(filemtime($path1)!=filemtime($path2)){//check file modified time:
     return array('path1'=>$path1,'path2'=>$path2,'status'=>'modified');
  }else if (strtoupper(dechex(crc32(file_get_contents($path1))))!=strtoupper(dechex(crc32(file_get_contents($path2))))){ //check contents:
     return array('path1'=>$path1,'path2'=>$path2,'status'=>'contents'); 
  }//no differences:
 
  return false;
}