para

head

The Windows half of C<Prompt::Hidden>: one line read through C<_getch> from
C<msvcrt>, which returns a key without echoing it.


Loaded B<only> when C<$*DISTRO.is-win> — C<use NativeCall> costs about 70 ms on
Rakudo, and a Unix program should not pay it for a branch it cannot take.


Nothing here runs on Raku++/Windows either: the engine has C<prompt(:hidden)>
natively, so C<Prompt::Hidden> takes the C<'core'> backend and never reaches
this file.



unit module Prompt::Hidden::Win32;

use NativeCall;

# _getch: one keypress, unechoed, unbuffered. Taking it means taking the line
# discipline too — there is no kernel to honour backspace for us.
sub _getch(--> int32) is native('msvcrt') is symbol('_getch') { * }

constant CTRL-C     = 3;
constant CTRL-Z     = 26;
constant BACKSPACE  = 8;
constant DELETE     = 127;
constant RETURN     = 13;
constant NEWLINE    = 10;

# 0x00 and 0xE0 introduce a two-byte function/arrow key; the second byte has to
# be swallowed or it lands in the password as a stray character.
constant PREFIX-A   = 0;
constant PREFIX-B   = 224;

#| One line, never echoed. Nil at end of input, as `prompt` gives.
sub getch-line(--> Str) is export {
    my @chars;
    loop {
        my $ch = _getch();
        return @chars.join                 if $ch == RETURN | NEWLINE;
        exit 130                           if $ch == CTRL-C;
        return @chars ?? @chars.join !! Nil if $ch == CTRL-Z || $ch < 0;
        if $ch == BACKSPACE || $ch == DELETE {
            @chars.pop if @chars;
            next;
        }
        if $ch == PREFIX-A || $ch == PREFIX-B {
            _getch();                      # discard the second byte
            next;
        }
        @chars.push: $ch.chr;
    }
}


root

Hidden

README

React

=begin React :component<HeaderCol> :id<menu> 
=para L<Documentation|/doc/introduction>
=para L<Modules| /mods>
=para L<Examples| file:../examples/index.podlite>
=para L<AI|file:../mcp/index.podlite>
=para L<Download |file:../download/index.podlite>
=para L<About|file:../about/index.podlite>
=para 🔍 K<⌘K>/K<ctrl-K>
=end React


=begin React :component<HeaderCol> :id<footer>  
=begin nested :!nested
=item1 B<Language>
    =item2 L<Get started|file:../getting-started/getting-started.podlite>
    =item2 L<Why Raku?|/doc/language/faq#Why-should-I-learn-Raku-What's-so-great-about-it>
    =item2 L<Try Raku|https://glot.io/new/raku>
    =item2 L<Download | file:../download/index.podlite>
    =item2 L<Raku cheat sheet|https://github.com/Raku/mu/blob/master/docs/Perl6/Cheatsheet/cheatsheet.txt>
    =item2 L<Raku on Exercism|https://exercism.org/tracks/raku>
    =item2 L<Wikipedia|https://en.wikipedia.org/wiki/Raku_(programming_language)>

=end nested
=begin nested :!nested

=item1 B<L<Documentation|/doc>>
    =item2 L<Getting started, Migration guides from other languages, & Tutorials | file:../doc/introduction.podlite>
    =item2 L<Language References|file:../doc/reference.podlite>
    =item2 L<Type Reference| file:../doc/types.podlite>
    =item2 L<Miscellaneous| file:../doc/miscellaneous.podlite>
    =item2 L<FAQs (Frequently Asked Questions)|/doc/language/faq>
    =item2 L<Community|/doc/language/community>
    =item2 L<The list of all documents|file:../doc/index.podlite>
    =item2 L<Hand these documents to an AI assistant|file:../mcp/index.podlite>

=end nested
=begin nested :!nested
=item1 B<Learning>
    =item2 L<The Raku Guide|https://raku.guide/>
    =item2 L<Wikibook |https://en.wikibooks.org/wiki/Raku_Programming>
    =item2 L<Books |https://perl6book.com/>
    =item2 L<Rosetta Code | https://www.raku.org/community/rosettacode>
    =item2 L<Learn Raku in Y minutes|https://learnxinyminutes.com/docs/raku/>
    =item2 L<Golfing |https://github.com/AlexDaniel/raku-golf-cheatsheet>
=end nested
=begin nested :!nested

=item1 B<Explore>
    =item2 L<Raku Blog Aggregator|https://planet.raku.org/>
    =item2 L<Rakudo Weekly|https://rakudoweekly.blog/>
    =item2 L<The Weekly Challenge |https://perlweeklychallenge.org/>
    =item2 L<Raku Advent Calendar|https://raku-advent.blog/>

=end nested
=end React


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=begin React :component<CookieConsent> :id<CookieConsent> :buttonCaption("Got it!")
=para
This website uses cookies for analytics.
=end React


Win32

Prompt::Hidden::Win32

Prompt::Hidden v0.0.3

Authors

License

Dependencies

Test Dependencies

Provides

Documentation