How do I read any one key in Bash?

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Solution 1

You are better off using dialog as jm666 mentioned, but there are other ways to skin that cat.

read -n 1 x; while read -n 1 -t .1 y; do x="$x$y"; done

Basically wait until you read a character and then spin consuming input until .1 seconds has passed w/o input.

Warning, fast typists could get annoyed. You might need to tweak that timeout.

Solution 2

Not a direct answer to your question - but the way of solution:

You probably should check the "dialog" utility for creating "ncurses" (screen oriented) dialog boxes from the shell. see: http://hightek.org/dialog/

Google form some examples, or check: http://unstableme.blogspot.sk/2009/12/linux-dialog-utility-short-tutorial.html

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biggles5107
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biggles5107

Updated on June 11, 2022

Comments

  • biggles5107
    biggles5107 over 1 year

    I can get read -n 1 KEY to get most keys, except for keys which are represented by multiple characters. For example, if I press the up arrow key:

    $ read -n 1; echo
    ^[[A
    $ [A
    

    As you can see, read only takes the Esc and the [A is left over.

    What I want to be able to do in a script is:

    1. Go through a list with the arrow keys and press Enter to do something with it
    2. For other actions, press different keys.
  • Seth Robertson
    Seth Robertson over 11 years
    @bi99l35: I guess 2400 baud dialup connections are pretty rare, so that should be safe.
  • Alfe
    Alfe over 10 years
    Still not good when you copy&paste some text. Then no timeout is fast enough to detect this. We should use the terminfo to find out whether we have a multibyte keypress at hand.
  • dylnmc
    dylnmc about 9 years
    This doesn't work for me (linux) when the character is Enter or Space or Tab. It does work for Backspace and even Esc, though.