1NULL(4) Linux Programmer's Manual NULL(4)
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6 null, zero - data sink
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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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22 /dev/null
23 /dev/zero
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26 If these devices are not writable and readable for all users, many pro‐
27 grams will act strangely.
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30 chown(1), mknod(1), full(4)
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33 This page is part of release 3.53 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)