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