Term::TermKey::Async - terminal key input using libtermkey with IO::Async


 use Term::TermKey::Async qw( FORMAT_VIM KEYMOD_CTRL );
 use IO::Async::Loop;
 my $loop = IO::Async::Loop->new();
 my $tka = Term::TermKey::Async->new(
    term => \*STDIN,

    on_key => sub {
       my ( $self, $key ) = @_;
       print "Got key: ".$self->format_key( $key, FORMAT_VIM )."\n";
       $loop->loop_stop if $key->type_is_unicode and
                           $key->utf8 eq "C" and
                           $key->modifiers & KEYMOD_CTRL;
 $loop->add( $tka );


This class implements an asynchronous perl wrapper around the libtermkey library, which provides an abstract way to read keypress events in terminal-based programs. It yields structures that describe keys, rather than simply returning raw bytes as read from the TTY device.

This class is a subclass of IO::Async::Handle, allowing it to be put in an IO::Async::Loop object and used alongside other objects in an IO::Async program. It internally uses an instance of Term::TermKey to access the underlying C library. For details on general operation, including the representation of keypress events as objects, see the documentation on that class.

Proxy methods exist for normal accessors of Term::TermKey, and the usual behaviour of the getkey or other methods is instead replaced by the on_key event.


The following events are invoked, either using subclass methods or CODE references in parameters:

on_key $key

Invoked when a key press is received from the terminal. The $key parameter will contain an instance of Term::TermKey::Key representing the keypress event.


$tka = Term::TermKey::Async->new( %args )

This function returns a new instance of a Term::TermKey::Async object. It takes the following named arguments:

term => IO or INT

Optional. File handle or POSIX file descriptor number for the file handle to use as the connection to the terminal. If not supplied STDIN will be used.


The following named parameters may be passed to new or configure:

flags => INT

libtermkey flags to pass to constructor or set_flags.

on_key => CODE

CODE reference for the on_key event.


$tk = $tka->termkey

Returns the Term::TermKey object being used to access the libtermkey library. Normally should not be required; the proxy methods should be used instead. See below.

$flags = $tka->get_flags

$tka->set_flags( $flags )

$canonflags = $tka->get_canonflags

$tka->set_canonflags( $canonflags )

$msec = $tka->get_waittime

$tka->set_waittime( $msec )

$str = $tka->get_keyname( $sym )

$sym = $tka->keyname2sym( $keyname )

( $ev, $button, $line, $col ) = $tka->interpret_mouse( $key )

$str = $tka->format_key( $key, $format )

$key = $tka->parse_key( $str, $format )

$key = $tka->parse_key_at_pos( $str, $format )

$cmp = $tka->keycmp( $key1, $key2 )

These methods all proxy to the Term::TermKey object, and allow transparent use of the Term::TermKey::Async object as if it was a subclass. Their arguments, behaviour and return value are therefore those provided by that class. For more detail, see the Term::TermKey documentation.


Paul Evans <>