What is a file [handle]? This is one of the various kinds of [Tcl handles] which is returned by [Tcl] commands such as [open], [[add other commands here that return this type of thing - perhaps relating to sockets, channels, other?]] They are a symbolic representation of an underlying operating system construct that represents an open input or output file/device. Examples: set handle [open $filename w] puts $handle $line close $handle ---- The Tcl man pages use the term [channel]. Unix calls the underlying construct a file descriptor. [MHo] 2017-05-19: I noticed that file handles are "recycled", so if a specific handle is closed, short after that a newly opened file gets the same handle. ---- '''[ak] - 2017-05-19 20:43:35''' That is, I believe, because of unix recycling the underlying file descriptor. I am not sure if it applies to Windows as well. The recycling of the standard channels OTOH is something Tcl does by itself IOW ======tcl close stdout open some/file ====== The channel for some/file now is "stdout". Works for sockets, pipes, etc. The first new channel after closing one of stdout, stderr, stdin becomes that channel. ---- !!!!!! %| [Category Glossary] |% !!!!!!