plucky (3) null.3tcl.gz

Provided by: tcl-memchan_2.3+dfsg-1build1_amd64 bug

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