Originální popis anglicky:
nice - change process priority
Návod, kniha: Linux Programmer's Manual
#include <unistd.h>
int nice(int inc);
nice adds
inc to the nice value for the calling pid. (A large nice
value means a low priority.) Only the superuser may specify a negative
increment, or priority increase.
On success, zero is returned. On error, -1 is returned, and
errno is set
appropriately.
- EPERM
- 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.
SVr4, SVID EXT, AT&T, X/OPEN, BSD 4.3. However, the Linux and glibc (earlier
than glibc 2.2.4) return value is nonstandard, see below. SVr4 documents an
additional EINVAL error code.
Note that the routine is documented in SUSv2 and POSIX 1003.1-2003 to return the
new nice value, while the Linux syscall and (g)libc (earlier than glibc 2.2.4)
routines return 0 on success. The new nice value can be found using
getpriority(2). Note that an implementation in which
nice
returns the new nice value can legitimately return -1. To reliably detect an
error, set
errno to 0 before the call, and check its value when
nice returns -1.
nice(1),
fork(2),
getpriority(2),
setpriority(2),
capabilities(7),
renice(8)
