Practical Programming in Tcl & Tk, Third Edition By Brent B. Welch
Table of Contents
Chapter 52. Tcl/Tk 8.1
Serial Line I/O
The serial line drivers were converted to use threads so you can wait for I/O with fileevent when using serial devices. There is no API change here, but this was a limitation that was annoying in previous Tcl releases.
tcl_platform(user)
The tcl_platform(user) array element records the currently logged in user. This masks difference in environment variables and system calls used to get this information on different platforms.
