xref: /titanic_41/usr/src/man/man7d/zero.7d (revision 989f28072d20c73ae0955d6a1e3e2fc74831cb39)
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Copyright 1989 AT&T Copyright (c) 1990, Sun Microsystems, Inc. All Rights Reserved
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ZERO 7D "Jul 3, 1990"
NAME
zero - source of zeroes
DESCRIPTION

A zero special file is a source of zeroed unnamed memory.

Reads from a zero special file always return a buffer full of zeroes. The file is of infinite length.

Writes to a zero special file are always successful, but the data written is ignored.

Mapping a zero special file creates a zero-initialized unnamed memory object of a length equal to the length of the mapping and rounded up to the nearest page size as returned by sysconf. Multiple processes can share such a zero special file object provided a common ancestor mapped the object MAP_SHARED.

FILES
/dev/zero

SEE ALSO

fork(2), mmap(2), sysconf(3C)