untar unzip decompress files in tcl

[IdRatherBOutdoors]

I am trying to create a program to transfer a file and decompress it. I have a TK GUI to select the file, and select the folder to place it into. This part works ok, but I have been unable to locate any information as to whether I can use TCL to uncompress the files. I am running this on Windows NT, Linux, and Unix.
Does anybody know of a way to do this in TCL or know of some place that would have information about this?

Thanks for any help you could provide.

 

[marsd]

http://mini.net/tcl/2466