PHP常用正则表达式

匹配单引号或双引号之间的内容

源字符串：

<div class="ts-background-image ts-animate ts-scale" data-bg-image="assets/img/bg/11.png"></div><div class="ts-background-image ts-animate ts-scale" data-bg-image='assets/img/bg/22.jpg'></div><form class="ts-form ts-form-email" data-php-path="assets/php/email.php"></form>

正则一：

([\"\'])([^"\.]*\.[^"]{2,4})\1

PHP代码；

preg_match_all('/([\"\'])([^"\.]*\.[^"]{2,4})\1/', $txt, $matches);
var_dump($matches);die;

匹配结果：

array(3) {
  [0]=>
  array(3) {
    [0]=>
    string(22) ""assets/img/bg/11.png""
    [1]=>
    string(22) "'assets/img/bg/22.jpg'"
    [2]=>
    string(22) ""assets/php/email.php""
  }
  [1]=>
  array(3) {
    [0]=>
    string(1) """
    [1]=>
    string(1) "'"
    [2]=>
    string(1) """
  }
  [2]=>
  array(3) {
    [0]=>
    string(20) "assets/img/bg/11.png"
    [1]=>
    string(20) "assets/img/bg/22.jpg"
    [2]=>
    string(20) "assets/php/email.php"
  }
}

正则二（限定了指定的后缀）：

([\"\'])([^\"\.]*\.(png|jpg|svg|gif|jpeg|html))\1

匹配结果：

array(4) {
  [0]=>
  array(2) {
    [0]=>
    string(22) ""assets/img/bg/11.png""
    [1]=>
    string(22) "'assets/img/bg/22.jpg'"
  }
  [1]=>
  array(2) {
    [0]=>
    string(1) """
    [1]=>
    string(1) "'"
  }
  [2]=>
  array(2) {
    [0]=>
    string(20) "assets/img/bg/11.png"
    [1]=>
    string(20) "assets/img/bg/22.jpg"
  }
  [3]=>
  array(2) {
    [0]=>
    string(3) "png"
    [1]=>
    string(3) "jpg"
  }
}

匹配空行

^(\s*)$\n

正则表达式测试工具

RegexBuddy

在线测试工具

https://regex101.com/