1NULL(4)                    Linux Programmer's Manual                   NULL(4)
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NAME

6       null, zero - data sink
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DESCRIPTION

9       Data written to a null or zero special file is discarded.
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11       Reads  from  the  null  special  file  always return end of file (i.e.,
12       read(2) returns 0), whereas reads from zero always  return  bytes  con‐
13       taining zero (\0 characters).
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15       null and zero are typically created by:
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17              mknod -m 666 /dev/null c 1 3
18              mknod -m 666 /dev/zero c 1 5
19              chown root:root /dev/null /dev/zero
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FILES

22       /dev/null
23       /dev/zero
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NOTES

26       If these devices are not writable and readable for all users, many pro‐
27       grams will act strangely.
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SEE ALSO

30       chown(1), mknod(1), full(4)
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COLOPHON

33       This page is part of release 3.25 of the Linux  man-pages  project.   A
34       description  of  the project, and information about reporting bugs, can
35       be found at http://www.kernel.org/doc/man-pages/.
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39Linux                             2009-02-23                           NULL(4)