nice - change process priority
int nice(int inc);
nice adds inc to the priority for the calling pid. Only
the superuser may specify a negative increment, or prior
Note that internally, a higher number is a higher prior
ity. Do not confuse this with the priority scheme as used
by the nice interface.
On success, zero is returned. On error, -1 is returned,
and errno is set appropriately.
EPERM A non-super user attempts to do a priority
increase, a numerical decrease, by supplying a neg
SVr4, SVID EXT, AT&T, X/OPEN, BSD 4.3. SVr4 documents an
additional EINVAL error code.
nice(1), setpriority(2), fork(2), renice(8)