PHP文件扩展名问题[重复]

Possible Duplicate:
How to extract a file extension in PHP?

How can we get file extension with any php function?

Whether there is some built-in function in php. I am using some explode function but any other exists

Yes, you can .......

Just Use the following code.......

Pass path of file to this PHP function and get extension.

    function extension($path) {
      $qpos = strpos($path, "?");

       if ($qpos!==false) $path = substr($path, 0, $qpos);

        $extension = pathinfo($path, PATHINFO_EXTENSION);

        return $extension;
       } 

You can use pathinfo for this:

echo pathinfo("foo.txt", PATHINFO_EXTENSION);

But rolling your own with strrpos is not difficult as well.

Yes, using the Pathinfo() function.

<?php
    $path_parts = pathinfo('/www/htdocs/inc/lib.inc.php');
     echo $path_parts['dirname'], "
";
     echo $path_parts['basename'], "
";
     echo $path_parts['extension'], "
";
     echo $path_parts['filename'], "
"; // since PHP 5.2.0
?>

The above example will output:

/www/htdocs/inc
lib.inc.php
php //your extension
lib.inc

This is the code I use to get a file extension:

$filename = '/some/path/file.txt';
$extension = strtolower(substr(strrchr($filename, '.'), 1));

You can wrap it in your Utils class or something ;)