NULL

Section: Linux Programmer's Manual (4)
Updated: 2009-02-23
Index Return to Main Contents

NAME

null, zero - data sink

DESCRIPTION

Data written to a null or zero special file is discarded.

Reads from the null special file always return end of file (i.e., read(2) returns 0), whereas reads from zero always return bytes containing zero (\0 characters).

null and zero 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

FILES

/dev/null
/dev/zero

NOTES

If these devices are not writable and readable for all users, many programs will act strangely.

COLOPHON