A '''channel''' is the [Tcl] [I/O] model for character streams.

[[why are channels important to the tcl programmer?]]

[[how are channels different from other constructs in tcl?]]

[[how do I create/use/destroy a channel?]]


** Tcl Features **

   [stacked channel]:   a channel whose input or output is to/from another channel

   [reflected channel]:   a channel that is implemented at the script level

   [transform]:   describes the behaviour and interface of a stackable channel
   
   [virtual channel]:   an umbrella term for a channel implemented as a [reflected channel] and/or a [stacked channel]
   


** Commands **

   [chan]:   new in [Changes in Tcl/Tk 8.5%|%Tcl/Tk 8.5]

   [close]:   

   [eof]:   

   [fblocked]:   

   [fconfigure]:   

   [fcopy]:   

   [fileevent]:   

   [flush]:   

   [gets]:   

   [puts]:   

   [read]:   

   [socket]:   

   [tell]:   



** Half Bakery: Configurable Atom Type ** 

[PYK] 2014-05-17:  Tcl's channel mechanism currently only supports one type of atom:  the byte.  Could it be generalized to support arbitrary atom types? This could be put to use anywhere messages a passed, from [flow-based programming] to  (gasp) [UDP] implementations.  Hypothetical usage:

======
set chan [open {some resource descriptor}]
chan configure $chan -atom rfc2822
set msg [read $chan]
$msg headers
======

Yes, `[read]` would in this case construct new commands -- groovy eh?



** See Also **

   [Channel Implementations]:   enumerates all known channels, including those in extensions

   [Cplusplus streams and Tcl channels]:   

   [Tcl IO Drivers%|%The Tcl I/O system as seen by a driver (channel type)]:   



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