PHP Manual: Change the priority of the current process

Description

bool proc_nice ( int $increment )

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.