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2011-03-12 - Confoo 2011 presentation
Slides are available from the commandlinefu presentation at Confoo 2011: http://presentations.codeinthehole.com/confoo2011/
2011-01-04 - Moderation now required for new commands
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Functions

Is it a terminal?

Terminal - Is it a terminal?
isatty(){ test -t $1; }
2010-01-06 06:50:01
User: bhepple
Functions: test
3
Is it a terminal?

Oddly, the isatty(3) glibc C call doesn't have a direct analogue as a command 'isatty(1)'. All is not lost as you can use test(1).

For example, your script might be run from a tty or from a GUI menu item but it needs to get user-input or give feedback. Now your script can test STDIN with 'isatty 0' or STDOUT with 'isatty 1' and use xmessage(1) if the tty is not available.

The other way to test for this is with 'tty -s' - but that's only for STDIN.

Alternatives

There are 3 alternatives - vote for the best!

Terminal - Alternatives
[ -t 0 ] || exit 1
2009-11-20 23:14:49
User: cfajohnson
Functions: exit
Tags: shell script
21

Exit with error if script is not run in a terminal

tty > /dev/null 2>&1 || { aplay error.wav ; exit 1 ;}
2009-11-04 16:18:00
User: johnraff
Functions: aplay exit tty
Tags: shell script
0

If your script needs to be run in a terminal, this line at the top will stop it running if you absent-mindedly double-click the icon, perhaps intending to edit it. (Of course this won't help with scripts that run in the background.)

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