zero(4)

zero4

Data sink

Part of null(4).

Overview

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.)

Releases

19 releases since Debian 1.1 (Buzz); the text changed 15 times.

  1. 1.1–1.3
  2. 2.0
  3. 2.1
  4. 2.2
  5. 3.0–3.1
  6. 4.0
  7. 5.0
  8. 6.0
  9. 7
  10. 8
  11. 9
  12. 10
  13. 11
  14. 12
  15. 13
  16. Arch

From man-pages 6.19-1 in Arch Linux 2026-11-01. Parsed by carta from the page's man source.