Getting asynchronous user input in BASH
 

Hello

I have a BASH script running and would like to stop, without using Ctrl-C (this shuts down the entire script, which is not desired). So I need a clean exit from a running function. The bash built-in 'read' only accepts user input when prompted, and has a minimum of 1 second wait. It is not as 'clean' as I'd like ...(just hold down a key until the function execution catches up to the read ).

So here is what I would like: if the user presses a key at ANY time while a particular function is running, this key stroke would be caught and 'remembered'. The function would periodically check a variable or external event inside this loop, then do a clean exit from the function.

Any key should work, but a specific escape sequence like Ctrl-<something> would be fine.

Thanks in advance.

sed s|jake|Superjake|g

Depending on how the logic of your program handles the asynchronous input you might be able to do what you want with the trap command.

http://linux.die.net/man/1/trap

Another approach would be to make the asynchronous read a separate thread which signals the main thread when input has been received.

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Steve Stites