PHP
处理控制 | Process Control

proc_nice

proc_nice

(PHP 5, PHP 7)

proc_nice — 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 classPossible values
High priorityincrement < -9
Above normal priorityincrement < -4
Normal priorityincrement < 5 & increment > -5
Below normal priorityincrement > 5
Idle priorityincrement > 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

VersionDescription
7.2.0This 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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proc_open →

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https://secure.php.net/manual/en/function.proc-nice.php