array ( 0 => 'index.php', 1 => 'PHP Manual', ), 'head' => array ( 0 => 'UTF-8', 1 => 'en', ), 'this' => array ( 0 => 'function.proc-nice.php', 1 => 'proc_nice', ), 'up' => array ( 0 => 'ref.exec.php', 1 => 'Program execution Functions', ), 'prev' => array ( 0 => 'function.proc-get-status.php', 1 => 'proc_get_status', ), 'next' => array ( 0 => 'function.proc-open.php', 1 => 'proc_open', ), 'alternatives' => array ( ), 'source' => array ( 'lang' => 'en', 'path' => 'reference/exec/functions/proc-nice.xml', ), ); $setup["toc"] = $TOC; $setup["toc_deprecated"] = $TOC_DEPRECATED; $setup["parents"] = $PARENTS; manual_setup($setup); ?>
(PHP 5, PHP 7, PHP 8)
proc_nice — Change the priority of the current process
proc_nice() changes the priority of the current
process by the amount specified in priority
. A
positive priority
will lower the priority of the
current process, whereas a negative priority
will raise the priority.
proc_nice() is not related to proc_open() and its associated functions in any way.
priority
The new priority value, the value of this may differ on platforms.
On Unix, a low value, such as -20
means high priority
whereas positive values have a lower priority.
For Windows the priority
parameter has the
following meaning:
Priority class | Possible values |
---|---|
High priority |
priority < -9
|
Above normal priority |
priority < -4
|
Normal priority |
priority < 5 &
priority > -5
|
Below normal priority |
priority > 5
|
Idle priority |
priority > 9
|
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.
Version | Description |
---|---|
7.2.0 | This function is now available on Windows. |
Example #1 Using proc_nice() to set the process priority to high
<?php
// Highest priority
proc_nice(-20);
?>
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.