Get File Extension with PHP + Benchmark Results

I know you’ve probably seen this topic a hundred times, and so have I, but this one has a different twist. We already know that there are many ways to get the extension of a file, but which one is the fastest? That’s what I’m going to address right now.

Contenders

In each of the code examples $file is set to c:\\xampplite\\htdocs\\index.php.

String-to-Array Method


<?php
$ext = end(explode('.', $file));
echo $ext; // outputs 'php'
?>

Sub-String Method


<?php
$ext = substr($file, strrpos($file, '.')+1);
echo $ext; // outputs 'php'
?>

Path Info Method


<?php
$ext = pathinfo($file, PATHINFO_EXTENSION);
echo $ext; // outputs 'php'
?>

Setup

To test each of the contenders I put together a script that timed the execution of 1,000,000 iterations of each command. If you would like the script you can download it here.

Results

Get File Extension PHP Benchmark
Sub-String Method: 0.778156 seconds
String-to-Array Method: 1.889744 seconds
Path Info Method: 2.020036 seconds

Winner

Our winner? The Sub-String Method! Next time you reach for that line of code to get a file’s extension, go for gold, and choose the Sub-String Method.


<?php
$ext = substr($file, strrpos($file, '.')+1);
echo $ext; // outputs 'php'
?>

Comments

Stan says

August 9, 2011 at 5:47 PM

What if the filename is index.bak.php
- Josh Hartman says
  
  August 9, 2011 at 11:57 PM
  
  Well, the extension of that file would be php, so it would return php.
Martin says

January 2, 2012 at 8:11 PM

Sub-String Method

if $file=’noextension’, $ext will be substr($file, 1), this does not work well
so things go like:
- Josh Hartman says
  
  January 3, 2012 at 11:19 AM
  Yes, if you know that you are working with file names that have no extension then modify it like so:
```
<?php
$file = 'noextension';
$ext = (strrpos($file, '.')!==false) ? substr($file, strrpos($file, '.')+1) : '';
echo $ext;
?>
```