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NULL(4) Linux Programmer's 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 pro-
     grams 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)

COLOPHON

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     description  of  the project, information about reporting bugs, and the
     latest    version    of    this    page,    can     be     found     at
     https://www.kernel.org/doc/man-pages/.

Linux 2015-07-23 NULL(4)