topic Re: Exit loop with any keystroke in Operating System - HP-UX

Exit loop with any keystroke

Brian K. Arnholt — Wed, 12 Nov 2003 13:15:13 GMT

I have been reading the forums looking for a solution, searching on trap, stty... but I am at a loss...here's my issue:

I have a simple script that enters into a continous loop and runs a program to dipslay the contents of a file to the screen. I know I can exit out of the loop by hitting Ctrl-C, etc.

What I would like to do is exit the loop when a user presses ANY key, not just return, or Ctrl-C, etc.

Is there a way to do this?

Re: Exit loop with any keystroke

Mark Greene_1 — Wed, 12 Nov 2003 13:49:51 GMT

You can try this:

stty raw;char=`dd if=/dev/tty count=1 2>/dev/null`;stty -raw

mark

Re: Exit loop with any keystroke

Kent Ostby — Wed, 12 Nov 2003 14:04:27 GMT

Dug around on google and hacked together this.

Only I seem to have to hit 3 keystrokes to get it to quit.

Might give you some ideas.

Basically save the stty settings, send a message, turn off echo and -icanon and then have dd wait for an input character then restore the old stty settings:

old_tty_setting=$(stty -g)
echo "Hit key to break loop "
stty -icanon -echo
usethis=$(dd bs=1 count=1 of=/dev/null)
stty $old_tty_setting

Hope that helps or maybe someone can suggest why it would take multiple characters.

Re: Exit loop with any keystroke

James A. Donovan — Wed, 12 Nov 2003 15:42:38 GMT

Check this link. Good example script and explanation.

http://www.dbaoncall.net/references/ex_one_char.html

Re: Exit loop with any keystroke

Brian K. Arnholt — Thu, 13 Nov 2003 09:26:58 GMT

Thanks to all, Jim's link was the cleanest.