Extract a substring between two characters in a string PHP

use this code

$input = "[modid=256]";
preg_match('~=(.*?)]~', $input, $output);
echo $output[1]; // 256

working example http://codepad.viper-7.com/0eD2ns

Use:

<?php

$str = "[modid=256]";
$from = "=";
$to = "]";

echo getStringBetween($str,$from,$to);

function getStringBetween($str,$from,$to)
{
    $sub = substr($str, strpos($str,$from)+strlen($from),strlen($str));
    return substr($sub,0,strpos($sub,$to));
}

?>