proc_nice

(PHP 5, PHP 7)

proc_nice — Change the priority of the current process

Description

proc_nice ( int $increment ) : bool

proc_nice() changes the priority of the current process by the amount specified in increment. A positive increment will lower the priority of the current process, whereas a negative increment will raise the priority.

proc_nice() is not related to proc_open() and its associated functions in any way.

Parameters

increment

The new priority value, the value of this may differ on platforms.

On Unix, a low value, such as -20 means high priority wheras a positive value have a lower priority.

For Windows the increment parameter have the following meanings:

Priority class	Possible values
High priority	`increment` `< -9`
Above normal priority	`increment` `< -4`
Normal priority	`increment` `< 5` & `increment` `> -5`
Below normal priority	`increment` `> 5`
Idle priority	`increment` `> 9`

Return Values

Returns true on success or false on failure. If an error occurs, like the user lacks permission to change the priority, an error of level E_WARNING is also generated.

Examples

Example #1 Using proc_nice() to set the process priority to high

<?php
// Highest priority
proc_nice(-20);
?>

Changelog

Version	Description
7.2.0	This function is now available on Windows.

Notes

Note: Availability

proc_nice() will only exist if your system has 'nice' capabilities. 'nice' conforms to: SVr4, SVID EXT, AT&T, X/OPEN, BSD 4.3.

Note: Windows only

proc_nice() will change the current process priority, even if PHP was compiled using thread safety.

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Licensed under the Creative Commons Attribution License v3.0 or later.
https://www.php.net/manual/en/function.proc-nice.php