setpriority(2)             DG/UX 4.30              setpriority(2)



     NAME
          setpriority - Set process scheduling priority.

     SYNOPSIS
          #include <sys/resource.h>

          int     setpriority (which, who, prio)
             int     which;
             int     who;
             int     prio;

     PARAMETERS
          which          Specifies how the argument who is to be
                         interpreted in identifying one or more
                         processes whose priorities will be set.  It
                         may take on the value PRIO_PROCESS,
                         PRIO_PGRP, or PRIO_USER.

          who            Identifies one or more processes whose
                         priorities will be set; may be a process ID,
                         a process group ID, or user ID, depending on
                         the value of which.

          prio           The new priority value.

     DESCRIPTION
          One or more processes are identified by the combination of
          the arguments which and who.  If which is PRIO_PROCESS, who
          is interpreted as a process ID and a single process is
          identified.  If which is PRIO_PGRP, who is interpreted as a
          process group ID, and all processes that are members of that
          group are identified.  If which is PRIO_USER, who is
          interpreted as a user ID, and all processes with an
          effective user id of who are identified.  A who value of 0
          is interpreted as the calling process's process ID, process
          group ID, and effective-user-id, respectively, for the three
          cases listed.  For example, all processes in the calling
          process's process group may be identified with which set to
          PRIO_PGRP and who set to zero.

          The setpriority call sets the priorities of all the
          identified processes to prio, subject to the access control
          constraints described below.  The access checks are applied
          to each process in the identified set.  If one or more
          processes fail the checks, setpriority still changes the
          priority of those processes that pass the checks, but the
          error return value will be given.

     ACCESS CONTROL
          In order to set a process's priority to a larger numerical
          value (less favorable scheduling) or leave it unchanged, the
          calling process must have an effective-user-id that is 0 or



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     setpriority(2)             DG/UX 4.30              setpriority(2)



          that matches the target process's effective-user_id.

          In order to set a process's priority to a smaller numerical
          value, the calling process must have an effective-user-id
          that is 0.

     RETURN VALUE
          0              Successful completion.

          -1             An error occurred.  Errno is set to indicate
                         the error.

     EXCEPTIONS
          Errno may be set to one of the following error codes:

          ESRCH          Using the which and who values specified, no
                         processes were located at all, or if any
                         processes were located, none passed the
                         access checks.

          EINVAL         which was not one of PRIO_PROCESS, PRIO_PGRP,
                         or PRIO_USER.

          EACCES         One or more (but not all) of the processes in
                         the identified set did not pass the access
                         checks described above.

     SEE ALSO
          nice(2), fork(2).


























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