PHP: Runtime Configuration

Runtime Configuration

The behaviour of these functions is affected by settings in php.ini.

**PCRE Configuration Options**
Name	Default	Changeable
pcre.backtrack_limit	"1000000"	`INI_ALL`
pcre.recursion_limit	"100000"	`INI_ALL`
pcre.jit	"1"	`INI_ALL`

For further details and definitions of the INI_* modes, see the Where a configuration setting may be set.

Here's a short explanation of the configuration directives.

pcre.backtrack_limit int: PCRE's backtracking limit. Defaults to 100000 for PHP < 5.3.7.
pcre.recursion_limit int: PCRE's recursion limit. Please note that if you set this value to a high number you may consume all the available process stack and eventually crash PHP (due to reaching the stack size limit imposed by the Operating System).
pcre.jit bool: Whether PCRE's just-in-time compilation is going to be used.

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User Contributed Notes 2 notes

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-6

chris at ocproducts dot com ¶

14 years ago


pcre.backtrack_limit sets the maximum bind length PREG calls (e.g. preg_replace_callback) can make. However the actual maximum seems to be approximately half the value set here, possibly due to the character encoding that PCRE runs with internally.

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-15

610010559 at qq dot com ¶

5 years ago


pcre.backtrack_limit can be set to -1; 
ini_set("pcre.backtrack_limit", "-1");

after i put the above code in my code, it works;
so i guess -1 means infinite(i am not very sure ,but it works); 
so when you have not idea how much it should be set in your program, you can try this.

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