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zero(4) [freebsd man page]

ZERO(4) 						   BSD Kernel Interfaces Manual 						   ZERO(4)

NAME
zero -- the zero device DESCRIPTION
The zero device accepts and reads data as any ordinary (and willing) file, but throws away any data written to it, and returns an endless supply of null bytes when read. FILES
/dev/zero SEE ALSO
full(4), null(4) HISTORY
A zero device appeared in 4.4BSD. BSD
April 7, 1996 BSD

Check Out this Related Man Page

PTY(4)							   BSD Kernel Interfaces Manual 						    PTY(4)

NAME
pty -- BSD-style compatibility pseudo-terminal driver SYNOPSIS
device pty DESCRIPTION
The pty driver provides support for the traditional BSD naming scheme that was used for accessing pseudo-terminals. When the device /dev/ptyXX is being opened, a new terminal shall be created with the pts(4) driver. A device node for this terminal shall be created, which has the name /dev/ttyXX. New code should not try to allocate pseudo-terminals using this interface. It is only provided for compatibility with older C libraries that tried to open such devices when posix_openpt(2) was being called. FILES
The BSD-style compatibility pseudo-terminal driver uses the following device names: /dev/pty[l-sL-S][0-9a-v] Pseudo-terminal master devices. /dev/tty[l-sL-S][0-9a-v] Pseudo-terminal slave devices. DIAGNOSTICS
None. SEE ALSO
posix_openpt(2), pts(4), tty(4) HISTORY
A pseudo-terminal driver appeared in 4.2BSD. BUGS
Unlike previous implementations, the master slave device nodes are destroyed when the PTY becomes unused. A call to stat(2) on a nonexistent master device will already cause a new master device node to be created. The master device can only be destroyed by opening and closing it. The pty driver cannot be unloaded, because it cannot determine if it is being used. BSD
August 20, 2008 BSD

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