Make sure a script is run in a terminal.

tty > /dev/null 2>&1 || { aplay error.wav ; exit 1 ;}

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.)

By: johnraff

2009-11-04 16:18:00

aplay exit tty shell script

2 Alternatives + Submit Alt

Make sure a script is run in a terminal.

Exit with error if script is not run in a terminal
This is sample output - yours may be different.
21

[ -t 0 ] || exit 1

cfajohnson · 2009-11-20 23:14:49 13
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.
This is sample output - yours may be different.
3

isatty(){ test -t $1; }

bhepple · 2010-01-06 06:50:01 4

What Others Think

I believe you meant "exit 1" instead of "exit 0". Zero signals that there was no error.

hackerb9 · 775 weeks and 6 days ago

Well, that's up to you I suppose. I meant "no error" in the sense that the problem was with how the script was started, not with the script itself. Set it to "1" if you prefer.

johnraff · 775 weeks and 4 days ago

On reflection you're right, hackerb9. Even if the script is blameless, if the user doesn't get the result (s)he wanted then there was an error. I'll edit the line.

johnraff · 775 weeks and 1 day ago

rahimhh21 · 109 weeks and 2 days ago

Perfecthomepugs · 100 weeks and 5 days ago

pugpuppies95 · 62 weeks and 6 days ago

What do you think?

Any thoughts on this command? Does it work on your machine? Can you do the same thing with only 14 characters?

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