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Packaging for AnyEvent::ReadLine::Gnu
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    AnyEvent::ReadLine::Gnu - event-based interface to Term::ReadLine::Gnu

     use AnyEvent::ReadLine::Gnu;

     # works always, prints message to stdout
     AnyEvent::ReadLine::Gnu->print ("message\n");

     # now initialise readline
     my $rl = new AnyEvent::ReadLine::Gnu prompt => "hi> ", on_line => sub {
        # called for each line entered by the user
        AnyEvent::ReadLine::Gnu->print ("you entered: $_[0]\n");

     # asynchronously print something
     my $t = AE::timer 1, 1, sub {
        print "async message 1\n"; # mind the \n

        # the same, but shorter:
        $rl->print ("async message 2\n");

     # do other eventy stuff...

    The Term::ReadLine module family is bizarre (and you are encouraged not
    to look at its sources unless you want to go blind). It does support
    event-based operations, somehow, but it's hard to figure out.

    It also has some utility functions for printing messages asynchronously,
    something that, again, isn't obvious how to do.

    This module has figured it all out for you, once and for all.

    $rl = new AnyEvent::ReadLine::Gnu key => value...
        Creates a new AnyEvent::ReadLine object.

        Actually, it only configures readline and provides a convenient way
        to call the show and hide methods, as well as readline methods -
        this is a singleton.

        The returned object is the standard Term::ReadLine::Gnu object, all
        methods that are documented (or working) for that module should work
        on this object.

        Once initialised, this module will also restore the terminal
        settings on a normal program exit.

        The callback will be installed with the "CallbackHandlerInstall",
        which means it handles history expansion and history, among other

        The following key-value pairs are supported:

        on_line => $cb->($string)
            The only mandatory parameter - passes the callback that will
            receive lines that are completed by the user.

            The string will be in locale-encoding (a multibyte character
            string). For example, in an utf-8 using locale it will be utf-8.
            There is no portable way known to the author to convert this
            into e.g. a unicode string.

        prompt => $string
            The prompt string to use, defaults to ">".

        name => $string
            The readline application name, defaults to $0.

        in => $glob
            The input filehandle (should be a glob): defaults to *STDIN.

        out => $glob
            The output filehandle (should be a glob): defaults to *STDOUT.

        These methods *hide* the readline prompt and text. Basically, it
        removes the readline feedback from your terminal.

        It is safe to call even when AnyEvent::ReadLine::Gnu has not yet
        been initialised.

        This is immensely useful in an event-based program when you want to
        output some stuff to the terminal without disturbing the prompt -
        just "hide" readline, output your thing, then "show" it again.

        Since user input will not be processed while readline is hidden, you
        should call "show" as soon as possible.

        Undos any hiding. Every call to "hide" has to be followed to a call
        to "show". The last call will redisplay the readline prompt, current
        input line and cursor position. Keys entered while the prompt was
        hidden will be processed again.

    $rl->print ($string, ...)
    AnyEvent::ReadLine::Gnu->print ($string, ...)
        Prints the given strings to the terminal, by first hiding the
        readline, printing the message, and showing it again.

        This function can be called even when readline has never been

        The last string should end with a newline.

    There are some issues with readline that can be problematic in
    event-based programs:

    blocking I/O
        Readline uses blocking terminal I/O. Under most circumstances, this
        does not cause big delays, but ttys have the potential to block
        programs indefinitely (e.g. on XOFF).

    unexpected disk I/O
        By default, readline does filename completion on TAB, and reads its
        config files.

        Tab completion can be disabled by calling "$rl->unbind_key (9)".

    tty settings
        After readline has been initialised, it will mangle the termios tty
        settings. This does not normally affect output very much, but should
        be taken into consideration.

    output intermixing
        Your program might wish to print messages (for example, log
        messages) to STDOUT or STDERR. This will usually cause confusion,
        unless readline is hidden with the hide method.

    Oh, and the above list is probably not complete.

     Marc Lehmann <>

    rltelnet - a simple tcp_connect-with-readline program using this module.

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