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null

Section: Devices and Network Interfaces (4)
Updated: 202-0-17
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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 ([aq][rs]0[aq] 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.)