null(4)                      Device Drivers Manual                     null(4)

NAME
       null, zero - data sink

DESCRIPTION
       Data written to the /dev/null and /dev/zero special files is discarded.

       Reads from /dev/null always return end of file (i.e., read(2) returns
       0), whereas reads from /dev/zero always return bytes containing zero
       ('\0' characters).

       These devices are typically created by:

           mknod -m 666 /dev/null c 1 3
           mknod -m 666 /dev/zero c 1 5
           chown root:root /dev/null /dev/zero

FILES
       /dev/null
       /dev/zero

NOTES
       If these devices are not writable and readable for all users, many
       programs will act strangely.

       Since Linux 2.6.31, reads from /dev/zero are interruptible by signals.
       (This change was made to help with bad latencies for large reads from
       /dev/zero.)

SEE ALSO
       chown(1), mknod(1), full(4)

Linux man-pages 6.7               2023-10-31                           null(4)