( int 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.
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.