(PHP 5, PHP 7, PHP 8)
proc_nice — Change the priority of the current process
proc_nice(int $priority): bool
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.
priorityThe 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.
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https://www.php.net/manual/en/function.proc-nice.php