(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.