Limit excerpt length

limit-excerpt-length.php

<?php
function getExcerpt($str, $startPos=0, $maxLength=100) {
	if(strlen($str) > $maxLength) {
		$excerpt   = substr($str, $startPos, $maxLength-3);
		$lastSpace = strrpos($excerpt, ' ');
		$excerpt   = substr($excerpt, 0, $lastSpace);
		$excerpt  .= '...';
	} else {
		$excerpt = $str;
	}
	return $excerpt;
}

function custom_excerpt_length( $length ) {
	return 20;
}
add_filter( 'excerpt_length', 'custom_excerpt_length', 5 );


?>