GETUID(2)                                               GETUID(2)

     NAME
          getuid, getgid, geteuid, getegid, getpid, getppid - get
          user, group, or process identity

     SYNOPSIS
          getuid()

          geteuid()

          getgid()

          getegid()

          getpid()

          getppid()

     DESCRIPTION
          Getuid returns the real user ID of the current process,
          geteuid the effective user ID.  The real user ID identifies
          the person who is logged in, in contradistinction to the
          effective user ID, which determines his access permission at
          the moment.  It is thus useful to programs which operate
          using the `set user ID' mode, to find out who invoked them.

          Getgid returns the real group ID, getegid the effective
          group ID.

          Getpid returns the process ID of the current process.  Most
          often it is used to generate uniquely-named temporary files.

          Getppid returns the process ID of the parent of the current
          process.

     SEE ALSO
          setuid(2), mktemp(3), getlogin(3)