1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
|
[comment {-*- tcl -*- doctools}]
[manpage_begin zero n 2.2]
[moddesc {Memory channels}]
[titledesc {Create and manipulate zero channels}]
[copyright {2004 Pat Thoyts <patthoyts@users.sourceforge.net>}]
[require Tcl]
[require memchan]
[description]
[para]
The command described here is only available in a not-yet released
version of the package. Use the CVS to get the sources.
[list_begin definitions]
[call [cmd zero]]
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.
[list_end]
[section OPTIONS]
Memory channels created by [cmd zero] provide one additional option to
set or query.
[list_begin definitions]
[lst_item [arg "-delay [opt milliseconds]"]]
A [cmd zero] channel is always writable and readable. This means
that all [cmd 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.
[list_end]
[see_also memchan fifo fifo2 null random]
[keywords zero null {in-memory channel} channel i/o]
[manpage_end]
|
