Preg_match regular expression matching prompt pcre. backtrack_limit solution _ PHP Tutorial

Source: Internet
Author: User
If the preg_match regular expression matches, the system prompts pcre. backtrack_limit. This article introduces the pcre. backtrack_limit solution for the preg_match regular expression matching prompt. if you need it, refer to it. Use the preg_match regular expression to extract the target content. if there is a problem, this article introduces the pcre. backtrack_limit solution for the preg_match regular expression matching prompt. if you need it, please refer to it.


Use the preg_match regular expression to extract the target content. if there is a problem with live or dead content, the code will be tested to survive.

Later, I suspect that PHP's preg_match has a string length limit, and found that the value of "pcre. backtrack_limit" is set to only 100000 by default.

Solution:

The code is as follows:
Ini_set ('pcre. backtrack_limit ', 999999999 );

Note: this parameter is available after php 5.2.0.

Also, let's talk about:
Pcre. recursion_limit

Pcre. recursion_limit is the recursive limitation of PCRE. if this item is set to a large value, it will consume the available stacks of all processes and eventually cause PHP to crash.

You can also modify the configuration to limit the memory usage: ini_set ('memory _ limit ', '64m ');, this makes it safer.

The code is as follows:
Ini_set ('pcre. recursion_limit ', 99999 );


References for other solutions

The code is as follows:

Pcre. backtrack_limit =-1

For more details, see http://www.bKjia. c0m/phper/31/42927 .htm

Bytes. Use the preg_match regular expression to extract the target content. if there is a problem in life or death, substitute...

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