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<! -- -*- tcl -*- doctools
-->
<html><head><title>zero - Memory channels </title></head>
<! -- Generated from file 'zero.man' by tcllib/doctools with format 'html'
-->
<! -- Copyright (c) 2004 Pat Thoyts <patthoyts@users.sourceforge.net>
-->
<! -- CVS: $Id$ zero.n
-->
<h1> zero(n) 2.2 "Memory channels"</h1>
<a name="name"><h2>NAME</h2>
<p> zero - Create and manipulate zero channels
<a name="synopsis"><h2>SYNOPSIS</h2>
package require <b>Tcl</b><br>
package require <b>memchan</b><br>
<br><table border=1 width=100% cellspacing=0 cellpadding=0><tr bgcolor=lightyellow><td bgcolor=lightyellow><table 0 width=100% cellspacing=0 cellpadding=0><tr valign=top ><td ><b class='cmd'>zero</b> </td></tr>
</table></td></tr></table>
<a name="description"><h2>DESCRIPTION</h2>
<p>
The command described here is only available in a not-yet released
version of the package. Use the CVS to get the sources.
<dl>
<dt><b class='cmd'>zero</b> <dd>
creates a zero channel which absorbs everything written into
it. Reading from a zero channel will return the requested number of null
bytes. These channels are essentially Tcl-specific variants of the
zero device for unixoid operating systems (/dev/zero). Transfering the
generated channel between interpreters is possible but does not make
much sense.
</dl>
<a name="options"><h2>OPTIONS</h2>
Memory channels created by <b class='cmd'>zero</b> provide one additional option to
set or query.
<dl>
<dt><i class='arg'>-delay ?milliseconds?</i><dd>
A <b class='cmd'>zero</b> channel is always writable and readable. This means
that all <b class='cmd'>fileevent</b>-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.
</dl>
<a name="seealso"><h2>SEE ALSO</h2>
memchan, fifo, fifo2, null, random
<a name="keywords"><h2>KEYWORDS</h2>
zero, null, in-memory channel, channel, i/o
<a name="copyright"><h2>COPYRIGHT</h2>
Copyright (c) 2004 Pat Thoyts <patthoyts@users.sourceforge.net><br>
</body></html>
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