PHP preg_match(): Unknown modifier '/'

对于preg_match用法:

<?php
// ...
$path = dirname(APP_PATH).'/data/monitor_hosts.txt';
$b = File::someRow($path, function($host) use ($url) {
	$pat = '/^[http(s)?://'.$host.'.*$/';
	preg_match($pat, $url, $matches);
	if (!$matches) {
		return true;
	}
	return false;
});
// ...           

报错

因为/ 斜线是特殊字符需要转义\/

$url = $request->get('url');

$path = dirname(APP_PATH).'/data/monitor_hosts.txt';
$b = File::someRow($path, function($host) use ($url) {
	$pat = '/^http(s)?:\/\/'.$host.'.*$/';
	preg_match($pat, $url, $matches);
	if ($matches) {
		return true;
	}
	return false;
});

           

https://github.com/mingzhanghui/urlGen/

https://www.php.net/manual/en/function.preg-match.php

preg_match ( string 

$pattern

 , string 

$subject

 [, array 

&$matches

 [, int 

$flags

 = 0 [, int

$offset

 = 0 ]]] ) : int

array(4) {
  [0]=>
  string(2) "ac"
  [1]=>
  string(1) "a"
  [2]=>
  string(0) ""
  [3]=>
  string(1) "c"
}
array(4) {
  [0]=>
  string(2) "ac"
  [1]=>
  string(1) "a"
  [2]=>
  NULL
  [3]=>
  string(1) "c"
}