null(7) — DG/UX 4.30



     null(7)                    DG/UX 4.30                     null(7)



     NAME
          null - the null file

     DESCRIPTION
          The null pseudo-device is the proverbial "bit bucket".  It
          works just as an ordinary disk file except that there is
          never any data to read, and written data is discarded.

          For the open and close system calls, user visible
          functionality is the same as for an ordinary disk file.

          For the read system call, user visible functionality is the
          same as for an ordinary disk file, except that the read will
          always return 0 bytes and the user's buffer will be
          unmodified.

          For the write system call, user visible functionality is the
          same as for an ordinary disk file, except that the data is
          discarded.

          There are no ioctl system calls that are specific to null.
          Other ioctl calls that apply to ordinary disk files also
          apply to null.

          Select always returns READY for both read and write
          operations.

     FILES
          /dev/null


























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