NICE(2) - man page online | system calls
Change process priority.
NICE(2) Linux Programmer's Manual NICE(2)
NAMEnice - change process priority
SYNOPSIS#include <unistd.h> int nice(int inc); Feature Test Macro Requirements for glibc (see feature_test_macros(7)): nice(): _BSD_SOURCE || _SVID_SOURCE || _XOPEN_SOURCE
DESCRIPTIONnice() adds inc to the nice value for the calling process. (A higher nice value means a low priority.) Only the superuser may specify a negative increment, or priority increase. The range for nice values is described in getpriority(2).
RETURN VALUEOn success, the new nice value is returned (but see NOTES below). On error, -1 is returned, and errno is set appropriately.
ERRORSEPERM The calling process attempted to increase its priority by supplying a negative inc but has insufficient privileges. Under Linux, the CAP_SYS_NICE capability is required. (But see the discussion of the RLIMIT_NICE resource limit in setr‐ limit(2).)
CONFORMING TOPOSIX.1-2001, POSIX.1-2008, SVr4, 4.3BSD. However, the Linux and (g)libc (earlier than glibc 2.2.4) return value is nonstandard, see below. SVr4 documents an additional EINVAL error code.
NOTESSUSv2 and POSIX.1 specify that nice() should return the new nice value. However, the Linux system call and the nice() library function provided in older versions of (g)libc (earlier than glibc 2.2.4) return 0 on success. The new nice value can be found using getpriority(2). Since glibc 2.2.4, nice() is implemented as a library function that calls getpriority(2) to obtain the new nice value to be returned to the caller. With this implementation, a successful call can legitimately return -1. To reliably detect an error, set errno to 0 before the call, and check its value when nice() returns -1.
SEE ALSOnice(1), renice(1), fork(2), getpriority(2), setpriority(2), capabilities(7), sched(7)
Linux 2015-08-08 NICE(2)
COLOPHONThis page is part of release 4.04 of the Linux man-pages project. A description of the project, information about reporting bugs, and the latest version of this page, can be found at http://www.kernel.org/doc/man-pages/.
|This manual||Reference||Other manuals|
capabilities(7) | chpst(8) | explain(1) | explain(3) | explain_nice(3) | explain_nice_or_die(3) | fio(1) | getrlimit(2) | inn.conf(5) | kdesrc-build(1) | mkvmerge(1) | nice(1) | sched(7) | sched_setaffinity(2) | sched_setattr(2) | sched_setparam(2) | sched_setscheduler(2) | schedtool(8) | sge_conf(5) | sge_queue_conf(5)
|refer to||capabilities(7) | feature_test_macros(7) | fork(2) | getpriority(2) | nice(1) | renice(1) | sched(7)|