null(7d) [opensolaris man page]

null(7D)							      Devices								  null(7D)

NAME

       null - the null file, also called the null device

SYNOPSIS

       /dev/null

DESCRIPTION

       Data written on the null special file, /dev/null, is discarded.

       Reads from a null special file always return 0 bytes.

       Mapping	a  null  special file creates an address reservation of a length equal to the length of the mapping, and rounded up to the nearest
       page size as returned by sysconf(3C). No resources are consumed by the reservation. Mappings can be placed in the resulting  address  range
       via subsequent calls to mmap with the -MAP_FIXED option set.

FILES

       /dev/null

SEE ALSO

       mmap(2), sysconf(3C)

SunOS 5.11							   4 April 2001 							  null(7D)

null(n) 																   null(n)

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NAME

       null - Create and manipulate null channels

SYNOPSIS

       package require Tcl

       package require memchan

       null

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DESCRIPTION

       The command described here is only available in a not-yet released version of the package. Use the CVS to get the sources.

       null   creates  a null channel which absorbs everything written into it. Reading from it is not possible, or rather will always return zero
	      bytes. These channels are essentially Tcl-specific variants of the null device for unixoid operating systems (/dev/null).  Transfer-
	      ing the generated channel between interpreters is possible but does not make much sense.

OPTIONS

       Memory channels created by null provide one additional option to set or query.

       -delay ?milliseconds?
	      A  null channel is always writable and readable. This means that all fileevent-handlers will fire continuously.  To avoid starvation
	      of other event sources the events raised by this channel type have a configurable delay. This option  is	set  in  milliseconds  and
	      defaults to 5.

       A  null	channel  is always writable and never readable. This means that a writable fileevent-handler will fire continuously and a readable
       fileevent-handler never at all. The exception to the latter is only the destruction of the channel which will cause the delivery of an  eof
       event to a readable handler.

SEE ALSO

       fifo, fifo2, memchan, random, zero

KEYWORDS

       channel, i/o, in-memory channel, null

COPYRIGHT

       Copyright (c) 1996-2003 Andreas Kupries <andreas_kupries@users.sourceforge.net>

Memory channels 							2.2								   null(n)