PHP Manual: Returns the error message of the last PCRE regex execution

string preg_last_error_msg()

Returns the error message of the last PCRE regex execution.

This function has no parameters.

Returns the error message on success, or "No error" if no error has occurred.

Example #1 preg_last_error_msg example

<?php

preg_match('/(?:\D+|<\d+>)*[!?]/', 'foobar foobar foobar');

if (preg_last_error() !== PREG_NO_ERROR) {
    echo preg_last_error_msg();
}

?>

The above example will output:

Backtrack limit exhausted

preg_last_error_msg