Find all files and filenames in a directory that match a substring

I am looping through a list of files in a directory and I want to match a substring that I have with the filename. If the filename contains the substring then return that file name so that I can delete it. I have done the following and its just returning everything:

while ($file = readdir($dir_handle)) { 

        $extension = strtolower(substr(strrchr($file, '.'), 1)); 
        if($extension == "sql" || $extension == "txt" ) {

            $pos = strpos($file, $session_data['us开发者_如何转开发er_id']);

            if($pos === true) {
                //unlink($file);
                echo "$file<br />"; 
            }else {
                // string not found
            }   
        }
} 

What am I doing wrong?

Thanks all for any help

strpos returns an integer or FALSE. You'll want to update your test to be

$pos !== FALSE 

Then - if you want to delete the file you can uncomment the unlink() call. I'm not sure what you mean by "return so I can delete".

Assuming you are on Linux you can do this using the [glob()][1] function with the GLOB_BRACE option:

$files = glob('*.{sql,txt}', GLOB_BRACE);

You might also mix in the user_id there.

Not sure if it works on Windows. See http://de.php.net/glob and mind the note about the GLOB_BRACE option.

if ($handle = opendir('/path/to/dir/') {
    $extensions = array('sql' => 1, 'txt' => 1);
    while (false !== ($file = readdir($handle))) { 
        $ext = strtolower(substr(strrchr($file, '.'), 1)); 
        if (isset($extensions[$ext]) && strpos($file, $session_data['user_id']) !== false)
            echo "$file<br />"; 
        else
            echo "no match<br />";
        }
    }
} 

you can use SPL to do it recursively

foreach (new DirectoryIterator('/path') as $file) {
    if($file->isDot()) continue;
    $filename = $file->getFilename();
    $pathname = $file->getPathname();
    if ( strpos ($filename ,".sql") !==FALSE ) {
        echo "Found $pathname\n";
        $pos = strpos($filename, $session_data['user_id']);
        ......
        #unlink($pathname); #remove your file
    }
}