Tcl Source Code

While I agree with the rest of dgp's comments, I do think it is important to distinguish between the channel and a "token" that identifies it, whether we call it a channel name or channel id. This is analogous to files and file descriptors, or perhaps more appropriately, Sys V streams, which might be the closest functionally to channels.

A Sys V stream or a Tcl channel is a programming construct that transports data (some hand waving here) and supports operations like read/write and transforms. The channel name/id is something used to identify an instance of such a construct. The two are not the same, and there need not even be a 1-1 relation between them. Consider if we had the equivalent of dup() in Tcl. We would then still have a single channel, as our data transfer construct, but now we have two identifiers/names for it. Calling close on the channel name would not terminate the channel, but the identifier would no longer reference it.

In Windows terms, what we are currently calling a channel id/name would be a channel handle. In Unix terms, it would be akin to a file descriptor. In any case the point is the channel is distinct from whatever is used to identify it, whether that is id, name, handle or descriptor.

Having said that I think **when the context is obvious** it would be all right to use "channel" as a synonym for the identifier if it reads better.