nice(S)                        6 January 1993                        nice(S)


 Name

    nice - change priority of a process

 Syntax


    cc ... -lc


    int nice (incr)
    int incr;


 Description

    The nice system call adds the value of incr to the nice value of the cal-
    ling process.  A process's nice value is a non-negative number for which
    a more positive value results in lower CPU priority.

    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 corre-
    sponding limit.


    [EPERM]        The nice system call 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 super
                   user.

 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.

 See also

    exec(S), nice(C)

 Standards conformance

    nice is conformant with:
    AT&T SVID Issue 2;
    and X/Open Portability Guide, Issue 3, 1989.