Practical Programming in Tcl & Tk, Third Edition

The fconfigure Command

The fconfigure command sets and queries several properties of I/O channels. The default settings for channels are suitable for most cases. If you do event-driven I/O you may want to set your channel into nonblocking mode. If you handle binary data, you should turn off end of line and character set translations. You can query the channel parameters like this:

fconfigure stdin
-blocking 1 -buffering none -buffersize 4096 -encoding
						iso8859-1 -eofchar {}-translation lf
					

Table 16-3 summarizes the properties controlled by fconfigure. They are discussed in more detail below.

Table 16-3. I/O channel properties controlled by fconfigure.

-blocking	Blocks until I/O channel is ready: 0 or 1.
-buffering	Buffer mode: none, line, or full ...