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null(4) Kernel Interfaces Manual null(4)
null, zero - data sink
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
/dev/null
/dev/zero
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.)
chown(1), mknod(1), full(4)
This page is part of the man-pages (Linux kernel and C library
user-space interface documentation) project. Information about
the project can be found at
⟨https://www.kernel.org/doc/man-pages/⟩. If you have a bug report
for this manual page, see
⟨https://git.kernel.org/pub/scm/docs/man-pages/man-pages.git/tree/CONTRIBUTING⟩.
This page was obtained from the tarball man-pages-6.9.1.tar.gz
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⟨https://mirrors.edge.kernel.org/pub/linux/docs/man-pages/⟩ on
2024-06-26. If you discover any rendering problems in this HTML
version of the page, or you believe there is a better or more up-
to-date source for the page, or you have corrections or
improvements to the information in this COLOPHON (which is not
part of the original manual page), send a mail to
man-pages@man7.org
Linux man-pages 6.9.1 2024-06-15 null(4)
Pages that refer to this page: full(4), dmsetup(8)
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HTML rendering created 2024-06-26 by Michael Kerrisk, author of The Linux Programming Interface. For details of in-depth Linux/UNIX system programming training courses that I teach, look here. Hosting by jambit GmbH. |
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