NAME
nice —
set program scheduling
priority
LIBRARY
Standard C Library (libc, -lc)
SYNOPSIS
#include <unistd.h>
int
nice(
int
incr);
DESCRIPTION
The
nice() function obtains the scheduling priority of the
process from the system and sets it to the priority value specified in
incr. The priority is a value in the range -20 to 20.
The default priority is 0; lower priorities cause more favorable scheduling.
Only a process with appropriate privileges may lower priorities.
Children inherit the priority of their parent processes via
fork(2).
RETURN VALUES
Upon successful completion,
nice() returns the new nice value
minus
NZERO. 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
nice(1),
fork(2),
setpriority(2),
renice(8)
STANDARDS
The
nice() function conforms to
X/Open
Portability Guide Issue 4, Version 2 (“XPG4.2”).
HISTORY
A
nice() syscall appeared in
Version 6
AT&T UNIX.