zero - Man Page

Create and manipulate zero channels


package require Tcl

package require memchan



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


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). Transferring the generated channel between interpreters is possible but does not make much sense.


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

-delay ?milliseconds?

A zero 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.

See Also

fifo, fifo2, memchan, null, random


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


2.2 Memory channels