(PHP 5, PHP 7)
proc_nice — Change the priority of the current process
$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.
incrementThe 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 class | Possible values | 
|---|---|
| High priority | increment< -9 | 
| Above normal priority | increment< -4 | 
| Normal priority | increment< 5 &increment> -5 | 
| Below normal priority | increment> 5 | 
| Idle priority | increment> 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.
  
Example #1 Using proc_open() to set the process priority to high
<?php
// Highest priority
proc_nice(-20);
?>
| Version | Description | 
|---|---|
| 7.2.0 | This function is now available on Windows. | 
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.