null(7) — DG/UX 5.4.2A



null(7)                          DG/UX 5.4.2                         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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