Check If a URL is Valid or Not

function is_valid_url ( $url )
$url = @parse_url($url);
if ( ! $url) {
return false;
}
$url = array_map('trim', $url);
$url['port'] = (!isset($url['port'])) ? 80 : (int)$url['port'];
$path = (isset($url['path'])) ? $url['path'] : '';
if ($path == ''){
$path = '/';
}
$path .= ( isset ( $url['query'] ) ) ? "?$url[query]" : '';
if ( isset ( $url['host'] ) AND $url['host'] != gethostbyname ( $url['host'] ) ){
if ( PHP_VERSION >= 5 ){
$headers = get_headers("$url[scheme]://$url[host]:$url[port]$path");
}else{
$fp = fsockopen($url['host'], $url['port'], $errno, $errstr, 30);
if ( ! $fp ){
return false;
}
fputs($fp, "HEAD $path HTTP/1.1\r\nHost: $url[host]\r\n\r\n");
$headers = fread ( $fp, 128 );
fclose ( $fp );
}
$headers = ( is_array ( $headers ) ) ? implode ( "\n", $headers ) : $headers;
return ( bool ) preg_match ( '#^HTTP/.*\s+[(200|301|302)]+\s#i', $headers );
}
return false;