nice(3) Library Functions Manual nice(3)
Name
nice - set program priority
Syntax
int nice(incr)
int incr;
Description
The scheduling priority of the process is augmented by incr. Positive priorities get less service than normal. Priority 10 is recommended
to users who wish to execute long-running programs without flack from the administration.
Negative increments are ignored except on behalf of the super-user. The priority is limited to the range -20 (most urgent) to 20 (least).
The priority of a process is passed to a child process by For a privileged process to return to normal priority from an unknown state,
should be called successively with arguments -40 (goes to priority -20 because of truncation), 20 (to get to 0), then 0 (to maintain com-
patibility with previous versions of this call).
Environment
In any mode, nice returns -1 and sets on an error. On success, the return value depends on the mode in which your program was compiled.
In POSIX or System V mode, it is the new priority; otherwise, it is zero. Note that, in POSIX and System V mode, -1 can indicate either
success or failure; must be used to determine which.
See Also
nice(1), fork(2), setpriority(2), renice(8)
nice(3)
