Tcl UPoC
The system sets the Tcl system encoding as UTF-8, so the file input and output are assumed to be encoded in UTF-8.
Tcl assumes the file names are UTF-8 if passed by a command-line routine as a string. This is the opposite of the C command-line convention.
The default Tcl
StdIn
/StdOut
/StdErr
have their encoding set to UTF-8.
Tcl does not automatically handle the Unicode Byte Order Mark (BOM).