<?php
$name = 'John Doe, Ph.D';
$get_name = preg_replace(array('/^([a-z]+(?:\s+[a-z]+)?).*$/', '/\s+/'), array('$1', '_'), strtolower($name));
echo $get_name;
echo "\n";
$name = 'Fred , M.Sc';
$get_name = preg_replace(array('/^([a-z]+(?:\s+[a-z]+)?).*$/', '/\s+/'), array('$1', '_'), strtolower($name));
echo $get_name;
echo "\n";
$name = 'Fred John Doe , B.A';
$get_name = preg_replace(array('/^([a-z]+(?:\s+[a-z]+)?).*$/', '/\s+/'), array('$1', '_'), strtolower($name));
echo $get_name;
echo "\n";
$name = 'John Doe';
$get_name = preg_replace(array('/^([a-z]+(?:\s+[a-z]+)?).*$/', '/\s+/'), array('$1', '_'), strtolower($name));
echo $get_name;
echo "\n";
$name = 'Fred';
$get_name = preg_replace(array('/^([a-z]+(?:\s+[a-z]+)?).*$/', '/\s+/'), array('$1', '_'), strtolower($name));
echo $get_name;
preferences:
57.27 ms | 402 KiB | 5 Q