NAME
nice —
set program scheduling
priority
LIBRARY
library “libc”
SYNOPSIS
#include
<unistd.h>
int
nice(int
incr);
DESCRIPTION
The
nice()
function adds incr to the scheduling priority of the
process. The priority is a value in the range -20 to 20. The default
priority is 0; lower priorities cause more favorable scheduling. Only the
super-user may lower priorities.
Children inherit the priority of their parent processes via fork(2).
RETURN VALUES
Upon successful completion, nice() returns
0, and errno is unchanged. Otherwise, -1 is returned,
the process' nice value is not changed, and errno is
set to indicate the error.
ERRORS
The nice() function will fail if:
- [
EPERM] - The incr argument is negative and the caller does not have appropriate privileges.
SEE ALSO
STANDARDS
The nice() function conforms to
IEEE Std 1003.1-2008 (“POSIX.1”)
except for the return value. This implementation returns 0 upon successful
completion but the standard requires returning the new nice value, which
could be -1.
HISTORY
A nice() syscall appeared in
Version 6 AT&T UNIX.