pcntl_getpriority

(PHP 5, PHP 7, PHP 8)

pcntl_getpriority — Get the priority of any process

Description

pcntl_getpriority(?int $process_id = null, int $mode = PRIO_PROCESS): int|false

pcntl_getpriority() gets the priority of process_id. Because priority levels can differ between system types and kernel versions, please see your system's getpriority(2) man page for specific details.

Parameters

process_id: If null, the process id of the current process is used.
mode: One of PRIO_PGRP, PRIO_USER, PRIO_PROCESS, PRIO_DARWIN_BG or PRIO_DARWIN_THREAD.

Return Values

pcntl_getpriority() returns the priority of the process or false on error. A lower numerical value causes more favorable scheduling.

Warning

This function may return Boolean false, but may also return a non-Boolean value which evaluates to false. Please read the section on Booleans for more information. Use the === operator for testing the return value of this function.

Changelog

Version	Description
8.0.0	`process_id` is nullable now.

User Contributed Notes 1 note

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jonathan at jcdesigns dot com ¶

16 years ago


This function is ideal for checking if a given process is running, I have seen solutions that involve running the system utilites like PS and parsing the answer, which should work fine, but this allows you to check a given PID with a single call

function CheckPID( $PID )
{
        // Check if the passed in PID represents a vlaid process in the system
        // Returns true if it does
        // Turn off non-fatal runtime warning for a moment as we know we 
        // will get one if the PID does not represent a valid process
 
    $oldErrorLevel = error_reporting(0);
    error_reporting( $oldErrorLevel & ~E_WARNING );
    $res = pcntl_getpriority($PID);
    error_reporting( $oldErrorLevel);
    return ! ( $res === false);
}

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