NAME

nice − change priority of a process

SYNOPSIS

/usr/ucb/cc  [ flag. . . ] file . . .

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 undue impact on system performance.

Negative increments are illegal, except when specified by the privileged user.  The priority is limited to the range −20 (most urgent) to 20 (least).  Requests for values above or below these limits result in the scheduling priority being set to the corresponding limit. 

The priority of a process is passed to a child process by fork(2).  For a privileged process to return to normal priority from an unknown state, nice should be called successively with arguments −40 (goes to priority −20 because of truncation), 20 (to get to 0), then 0 (to maintain compatibility with previous versions of this call). 

RETURN VALUE

Upon successful completion, nice returns 0.  Otherwise, a value of −1 is returned and errno is set to indicate the error. 

ERRORS

The priority is not changed if:

EACCES The value of incr specified was negative, and the effective user ID is not the privileged user. 

SEE ALSO

nice(1), renice(1M), priocntl(2), fork(2), getpriority(2), priocntl(2). 

  —  BSD Compatibility Package