Thursday, April 10, 2008

Disabling Terminal Flow Control Keystrokes

If you've ever encountered the situation where you've accidentally typed the <ctrl-s> keystroke and your terminal seems to 'hang', that's because you've typed the 'XOFF' special character which tells the terminal not to accept any more key inputs.

The way to restore terminal responsiveness is by typing the <ctrl-q> keystroke ('XON') to restore flow control. If you want do disable this feature, use the following command on your shell:


stty -ixon


 

5 comments:

Anonymous said...

stty -ixon
finally. what a retarded "feature".

Vincent Liu said...

I don't know what this 'feature' was originally for, but I'm sure it's there for some good historical reason that is not relevant anymore.

guy said...

This has to do with the fact that terminals emulate serial lines. Serial line as in RS-232 serial lines. RS-232 as in V.24 (the ITU name). V.24 as in V.90. And V.90 as in 56 kbit/s modems.

So what I mean to say is "terminals as in 56 kbit/s modems". Once you realize that, certain "features" of terminals become apparent, like flow control. (Keep in mind that when 1 kb/s modems were coming out, computers with 512 kb RAM were prevalent.)

Don't fix it if it ain't broke.

See `man termios' for more information. (http://www.freebsd.org/cgi/man.cgi?query=termios)

chuwaka said...

http://www.freebsd.org/cgi/man.cgi?query=termios - no available.

Anonymous said...

Thanks, Vincent.

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