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man pages section 7: Device and Network Interfaces

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Updated: July 2017



zero - source of zeroes


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.



See Also

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