NICE(E)             Linux Programmer's Manual             NICE(E)



NAME
       nice - change process priority

SYNOPSIS
       #include <unistd.h>

       int nice(int inc);

DESCRIPTION
       nice  adds  inc to the nice value for the calling pid.  (A
       large nice value means a low priority.)  Only  the  super-
       user   may  specify  a  negative  increment,  or  priority
       increase.

RETURN VALUE
       On success, zero is returned.  On error, -1  is  returned,
       and errno is set appropriately.

ERRORS
       EPERM  A non-super user attempts to do a priority increase
              by supplying a negative inc.

CONFORMING TO
       SVr4, SVID EXT, AT&T, X/OPEN, BSD 4.3. However, the  Linux
       and  glibc (earlier than glibc 2.2.4) return value is non-
       standard, see below.  SVr4 documents an additional  EINVAL
       error code.

NOTES
       Note that the routine is documented in SUSv2 to return the
       new nice value, while the Linux syscall and (g)libc  (ear-
       lier  than glibc 2.2.4) routines return 0 on success.  The
       new nice value can be found  using  getpriority(y).   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.

SEE ALSO
       nice(e),    getpriority(y),    setpriority(y),    fork(k),
       renice(e)



Linux                       2001-06-04                    NICE(E)