[SOLVED] Isolating a filename extension

[sh0wtym3]

Hey all

 

I have a line in my script that strips the file extension from the file name:

 

$ext = substr($filen, strpos($filen,'.'), strlen($filen)-1);

 

But this is not fool proof as I've noticed that some files contain more than one period. For example:

 

mysong_feat._artist.mp3

 

The code above would read the $ext variable as being ._ar instead of .mp3.

 

The strpos function finds the position of the first occurrence of a string. 

 

Is there a way to make it find the position of the last occurrence of a string? Or is there a different function I should be using?

 

Thanks in advance.

[flyhoney]

Try this: (untested)

<?php
function get_file_ext($filename)
{
	if (($pos = strrpos($filename, '.')) !== false)
	{
		return substr($filename, $pos, strlen($filename) - 1);
	} 
	else 
	{
		return '';
	} 
}
?>

[JonnoTheDev]

explode the file string into an array.

The file type will be the last element

 

$filename = "mysong_feat._artist.mp3";
$parts = explode(".", $filename);
print_r($parts);

[premiso]

Why not just pull the last 3 characters?

 

$ext = substr("file.ext.ext.php", -3);

 

Or, why not explode or split at the period and pull the last element of the array:

$ext = explode(".", "file.ext.ext.php");
$ext = $ext[count($ext)-1];

 

Or pathinfo

 

$path_parts = pathinfo('file.ext.ext.php');
$ext = $path_parts['extension'];

[flyhoney]

Why not just pull the last 3 characters?

 

$ext = substr("file.ext.ext.php", -3);

 

Or, why not explode or split at the period and pull the last element of the array:

$ext = explode(".", "file.ext.ext.php");
$ext = $ext[count($ext)-1];

 

Or pathinfo

 

$path_parts = pathinfo('file.ext.ext.php');
$ext = $path_parts['extension'];

 

Don't just pull last 3 chars, extension could be 1, 2 or 4+ chars.

 

explode works, just do some error checking to make sure that there is a '.' or else you will just end up returning the filename.

 

pathinfo works, but I think it suffers from the same problem as the explode method if the file has no extension.

[sh0wtym3]

Thanks guys, wasn't aware I could do all that, I'm still fairly new to php.

 

I'm going to explode the string (at the period) and pull the last element, makes sense.

[flyhoney]

Here is a pretty concise bit of code I found:

<?php
$filename = 'pterodactyl.wtf';
$ext = substr(($t = strrchr($filename, '.')) !== false ? $t : '', 1);
?>

 

In function form:

<?php
function get_file_extension($filename) 
{
    return substr(($t = strrchr($filename, '.')) !== false ? $t : '', 1);
}
?>

[premiso]

Why not just pull the last 3 characters?

 

$ext = substr("file.ext.ext.php", -3);

 

Or, why not explode or split at the period and pull the last element of the array:

$ext = explode(".", "file.ext.ext.php");
$ext = $ext[count($ext)-1];

 

Or pathinfo

 

$path_parts = pathinfo('file.ext.ext.php');
$ext = $path_parts['extension'];

 

Don't just pull last 3 chars, extension could be 1, 2 or 4+ chars.

 

explode works, just do some error checking to make sure that there is a '.' or else you will just end up returning the filename.

 

pathinfo works, but I think it suffers from the same problem as the explode method if the file has no extension.

 

$path_parts = pathinfo('file.ext.ext.php');
$ext = isset($path_parts['extension'])?$path_parts['extension']:'';

 

For explode:

$ext = explode(".", "file.ext.ext.php");
$ext = (count($ext)>1)?$ext[count($ext)-1]:'';

 

That would avoid any errors of no path being passed I would believe.

[flyhoney]

Use end

 

And won't explode return an array even if there is only one element?

 

$ext = explode(".", "file.ext.ext.php");
$ext = (count($ext) > 1) ? end($ext) : '';

[premiso]

Use end

 

And won't explode return an array even if there is only one element?

 

$ext = explode(".", "file.ext.ext.php");
$ext = (count($ext) > 1) ? end($ext) : '';

 

Yea I just did my testing and found that out =) And I guess I never looked for a function like end good to know =P

[flyhoney]

Sorry for continually posting, but I think I found a winner:

 

<?php
$filename = 'mypic.gif';
$ext = pathinfo($filename, PATHINFO_EXTENSION);
?>

[sh0wtym3]

Its ok flyhoney, I appreciate all the assistance.