- sscanf: documentation ( source)
- var_export: documentation ( source)
<?php
$str = "bla_string_bla_bla_bla";
$prefix = 'bla_';
sscanf($str, "$prefix%s", $str);
var_export($str);
echo "\n---\n";
$str = "string_bla_bla_bla";
sscanf($str, "$prefix%s", $str);
var_export($str);