Optimize Php function that is too slow - php

Question

i made this function to test if the content has 301 redirections..
Please can you help me opimize it better because it's too slow
function contains_http_301_link($content, $current_site){
$pattern = '~<a(.*?)href="([^"]+)"(.*?)>~';
$links = array();
// Check if there is a url in the content
if(preg_match_all($pattern, $content, $urls)) {
foreach($urls[0] as $url){
// get external links
if ( !strpos( $url, $current_site )) { // Is an external link
$vowels = array('"' ,"<a", " ", "href", "=", ">");
$links[] = str_replace($vowels, "", $url);
}
}
}
foreach ($links as $link) {
$_headers = #get_headers($link,1);
if($_headers && strpos( $_headers[0], '301')) {
return true;
}
}
return false;
}

Answer 1

I would change the last for-loop to:
<?php
stream_context_set_default(
array(
'http' => array(
'method' => 'HEAD'
)
))
);
foreach ($links as $link) {
$_headers = get_headers($link,1);
if($_headers && strpos( $_headers[0], '301')) {
return true;
}
}
?>
or as
$context = stream_context_create(array(
'http' => array(
'method' => 'HEAD'
)
);
foreach ($links as $link) {
$_headers = get_headers($link,1, $context);
if($_headers && strpos( $_headers[0], '301')) {
return true;
}
}
By the way: if the first of 10 links found will return 301, your function returns TRUE. The same if it is the last. So your function just checks if at least one has a redirect 301 (and not 302 or 303)