Console Application Keyboard event catch


#1

Dear All,

While doing the console application with Ruby, met below questions,
please help, thanks in advance,

  1. How to catch the Keyboard event, such as, how about the [TAB]
    key pressed, [CTRL] key and so on;
  2. How to backdisplay the string? Such as, when you type [cd]
    command at the windows command mode, and press [TAB] it will help to
    complete the directory name, such as [abc] directory, once you press
    again, it will delete the [abc] directory and display another one, such
    as [efg].

I try search from the google, but no result, please help thanks.

Regards,
Marble

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#2

On 7/2/07, removed_email_address@domain.invalid removed_email_address@domain.invalid wrote:

    2. How to backdisplay the string? Such as, when you type [cd]

command at the windows command mode, and press [TAB] it will help to
complete the directory name, such as [abc] directory, once you press
again, it will delete the [abc] directory and display another one, such
as [efg].

I try search from the google, but no result, please help thanks.

  1. TAB is character #9, Ctrl+A is (IIRC) 0, Ctrl+B 1, etc. If you want
    to catch all the combinations, you need to use special api, i.e. getch
    from msvcrt, or curses.

  2. BS (backspace, Ctrl+H) moves cursor one char left. CR (carriege
    return, 13) moves cursor to the start of the line (you need to
    overwrite everything you have written before, and it’s possible that a
    screen will scroll up, and LF (line feed) will be inserted by ruby)

  3. have a look at readline library, it may do what you are trying to
    achieve.

J.