在php中创建正则表达式

Question

My attempt 我的尝试

preg_match("/^logs.\d{24}.\d{24}.{4}$/", $input_line, $output_array);
If matched return \d{24} in echo

String 串

logs/532523532543353444444444/532523532543353444444444.log

Preg match peseudo-code : logs/{24 digitals}/{same24digits}.log Preg match伪代码： logs/{24 digitals}/{same24digits}.log

Both \\d{24} are the same number 两个\\d{24}是相同的数字

Question How to get the : If matched return \\d{24} in echo 问题如何获取：如果匹配，则在回显中返回\\ d {24}

Answer 1

You can use: 您可以使用：

if (preg_match('~^logs/(\d{24})/\1\.log$~', $input_line, $m))
   echo $m[1];

\\1 ia back-reference to first captured group ie (\\d{24}) \\1 ia反向引用第一个捕获的组，即(\\d{24})

Answer 2

logs\/(\d{24})\/\1.log