NICE(2-SVR4)        RISC/os Reference Manual         NICE(2-SVR4)



NAME
     nice - change priority of a time-sharing process

SYNOPSIS
     #include <unistd.h>

     int nice(int incr);

DESCRIPTION
     nice allows a process in the time-sharing scheduling class
     to change its priority.  The priocntl system call is a more
     general interface to scheduler functions.

     nice adds the value of incr to the nice value of the calling
     process.  A process's nice value is a non-negative number
     for which a more positive value results in lower CPU prior-
     ity.

     A maximum nice value of 39 and a minimum nice value of 0 are
     imposed by the system.  (The default nice value is 20.)
     Requests for values above or below these limits result in
     the nice value being set to the corresponding limit.

     EPERM         nice fails and does not change the nice value
                   if incr is negative or greater than 39 and the
                   effective user ID of the calling process is
                   not superuser.

     EINVAL        nice fails if called by a process in a
                   scheduling class other than time-sharing.

SEE ALSO
     exec(2), priocntl(2).
     nice(1) in the User's Reference Manual.

DIAGNOSTICS
     Upon successful completion, nice returns the new nice value
     minus 20.  Otherwise, a value of -1 is returned and errno is
     set to indicate the error.
















                        Printed 11/19/92                   Page 1