=encoding utf8

=head1 NAME

urxvtperl - rxvt-unicode's embedded perl interpreter

=head1 SYNOPSIS

   # create a file grab_test in some directory:

   sub on_sel_grab {
      warn "you selected ", $_[0]->selection;
      ()
   }

   # start a urxvt instance using it:

   urxvt --perl-lib path/to/somedirectory -pe grab_test

=head1 DESCRIPTION

Every time a terminal object gets created, extension scripts specified via
the C<perl> resource are loaded and associated with it.

Scripts are compiled in a 'use strict qw(vars subs)' and 'use utf8'
environment, and thus must be encoded as UTF-8.

Each script will only ever be loaded once, even in urxvtd, where
scripts will be shared (but not enabled) for all terminals.

You can disable the embedded perl interpreter by setting both "perl-ext"
and "perl-ext-common" resources to the empty string.

=head1 PREPACKAGED EXTENSIONS

A number of extensions are delivered with this release. You can find them
in F<< <libdir>/urxvt/perl/ >>, and the documentation can be viewed using
F<< man urxvt-<EXTENSIONNAME> >>.

You can activate them like this:

  urxvt -pe <extensionname>

Or by adding them to the resource for extensions loaded by default:

  URxvt.perl-ext-common: default,selection-autotransform

Extensions may add additional resources and C<actions>, i.e., methods
which can be bound to a key and invoked by the user. An extension can
define the resources it support using so called META comments,
described below. Similarly to builtin resources, extension resources
can also be specified on the command line as long options (with C<.>
replaced by C<->), in which case the corresponding extension is loaded
automatically. For this to work the extension B<must> define META
comments for its resources.

=head1 API DOCUMENTATION

=head2 General API Considerations

All objects (such as terminals, time watchers etc.) are typical
reference-to-hash objects. The hash can be used to store anything you
like. All members starting with an underscore (such as C<_ptr> or
C<_hook>) are reserved for internal uses and B<MUST NOT> be accessed or
modified).

When objects are destroyed on the C++ side, the perl object hashes are
emptied, so its best to store related objects such as time watchers and
the like inside the terminal object so they get destroyed as soon as the
terminal is destroyed.

Argument names also often indicate the type of a parameter. Here are some
hints on what they mean:

=over

=item $text

Rxvt-unicode's special way of encoding text, where one "unicode" character
always represents one screen cell. See L<ROW_t> for a discussion of this format.

=item $string

A perl text string, with an emphasis on I<text>. It can store all unicode
characters and is to be distinguished with text encoded in a specific
encoding (often locale-specific) and binary data.

=item $octets

Either binary data or - more common - a text string encoded in a
locale-specific way.

=item $keysym

an integer that is a valid X11 keysym code. You can convert a string
into a keysym and viceversa by using C<XStringToKeysym> and
C<XKeysymToString>.

=back

=head2 Extension Objects

Every perl extension is a perl class. A separate perl object is created
for each terminal, and each terminal has its own set of extension objects,
which are passed as the first parameter to hooks. So extensions can use
their C<$self> object without having to think about clashes with other
extensions or other terminals, with the exception of methods and members
that begin with an underscore character C<_>: these are reserved for
internal use.

Although it isn't a C<urxvt::term> object, you can call all methods of the
C<urxvt::term> class on this object.

Additional methods only supported for extension objects are described in
the C<urxvt::extension> section below.

=head2 META comments

Rxvt-unicode recognizes special meta comments in extensions that define
different types of metadata. These comments are scanned whenever a
terminal is created and are typically used to autoload extensions when
their resources or command line parameters are used.

Currently, it recognises these comments below. Individual components are
separated by colons (C<:>), and should not contain colons themselves -
there is also currently no escaping mechanism provided for this.

=over

=item #:META:RESOURCE:name:type:desc

The RESOURCE comment defines a resource used by the extension, where
C<name> is the resource name, C<type> is the resource type, C<boolean>
or C<string>, and C<desc> is the resource description.

The extension will be autoloaded when this resource is specified or used
as a command line parameter.

Example: matcher provides the C<matcher.launcher> resource by having this
comment:

   #:META:RESOURCE:%.launcher:string:default launcher command

Example: load this extension when the C<-tr> command line option or
resource name is used.

   #:META:RESOURCE:tr:boolean:set root pixmap as background

=item #:META:OSC:number:desc

The OSC comment specifies an OSC sequence, where C<number> is the
numerical OSC code and C<desc> is a short description that is currently
unused.

This will cause the extension to be autoloaded when the OSC sequence is
used for the first time.

Note that autoloading carries some extra responsibilities with it:
although the terminal cannot really protect itself against malicious
sources of command sequences, therefore relying on the programs running
I<inside> to sanitize data that they output, it is very common for
programs to emit command sequences from untrusted sources.

While this means that extensions should, as a defense-in-depth mechanism,
always consider whether OSC sequences are safe, autoloading automatically
exposes any autoloaded extension in all terminal windows, so extra care
should be taken.

Example: the background extension registers OSC C<20> like this:

   #:META:OSC:20:change/query background image

=item #:META:OSC_PERL:prefix:desc

The same as the OSC comment, but for the Perl OSC sequence (C<777>). The
C<prefix> should be unique among extensions, of course, which is most
easily arranged by using the extension name, although this is not
required.

Example: the overlay-osc extension registers its Perl OSC like this:

   #:META:OSC_PERL:overlay:man overlay-osc

=back

=head2 Hooks

The following subroutines can be declared in extension files, and will be
called whenever the relevant event happens.

The first argument passed to them is an extension object as described in
the in the C<Extension Objects> section.

B<All> of these hooks must return a boolean value. If any of the called
hooks returns true, then the event counts as being I<consumed>, and the
relevant action might not be carried out by the C++ code.

I<< When in doubt, return a false value (preferably C<()>). >>

=over

=item on_attach $term

Called when an extension package is attached to a running terminal
instance. Must return true in all cases, and runs with the same
limitations as C<on_init>.

Unlike C<on_init> or C<on_start>, this is called when the extension is
attached to a terminal, regardless of whether the extension is loaded
before or after the terminal is started. Extensions that need to do
something before they work can do it in this callback, as opposed to e.g.
C<on_init>, which might not be called.

=item on_init $term

Called after a new terminal object has been initialized, but before
windows are created or the command gets run. Most methods are unsafe to
call or deliver senseless data, as terminal size and other characteristics
have not yet been determined. You can safely query and change resources
and options, though. For many purposes the C<on_start> hook is a better
place.

=item on_start $term

Called at the very end of initialisation of a new terminal, just before
trying to map (display) the toplevel and returning to the main loop.

=item on_destroy $term

Called whenever something tries to destroy terminal, when the terminal is
still fully functional (not for long, though).

=item on_reset $term

Called after the screen is "reset" for any reason, such as resizing or
control sequences. Here is where you can react on changes to size-related
variables.

=item on_child_start $term, $pid

Called just after the child process has been C<fork>ed.

=item on_child_exit $term, $status

Called just after the child process has exited. C<$status> is the status
from C<waitpid>.

=item on_sel_make $term, $eventtime

Called whenever a selection has been made by the user, but before the
selection text is copied, so changes to the beginning, end or type of the
selection will be honored.

Returning a true value aborts selection making by urxvt, in which case you
have to make a selection yourself by calling C<< $term->selection_grab >>.

=item on_sel_grab $term, $eventtime

Called whenever a selection has been copied, but before the selection is
requested from the server.  The selection text can be queried and changed
by calling C<< $term->selection >>.

Returning a true value aborts selection grabbing. It will still be highlighted.

=item on_sel_extend $term

Called whenever the user tries to extend the selection (e.g. with a double
click) and is either supposed to return false (normal operation), or
should extend the selection itself and return true to suppress the built-in
processing. This can happen multiple times, as long as the callback
returns true, it will be called on every further click by the user and is
supposed to enlarge the selection more and more, if possible.

See the F<selection> example extension.

=item on_view_change $term, $offset

Called whenever the view offset changes, i.e. the user or program
scrolls. Offset C<0> means display the normal terminal, positive values
show this many lines of scrollback.

=item on_scroll_back $term, $lines, $saved

Called whenever lines scroll out of the terminal area into the scrollback
buffer. C<$lines> is the number of lines scrolled out and may be larger
than the scroll back buffer or the terminal.

It is called before lines are scrolled out (so rows 0 .. min ($lines - 1,
$nrow - 1) represent the lines to be scrolled out). C<$saved> is the total
number of lines that will be in the scrollback buffer.

=item on_osc_seq $term, $op, $args, $resp

Called on every OSC sequence and can be used to suppress it or modify its
behaviour. The default should be to return an empty list. A true value
suppresses execution of the request completely. Make sure you don't get
confused by recursive invocations when you output an OSC sequence within
this callback.

C<on_osc_seq_perl> should be used for new behaviour.

=item on_osc_seq_perl $term, $args, $resp

Called whenever the B<ESC ] 777 ; prefix ; string ST> command sequence
(OSC = operating system command) is processed. Cursor position and other
state information is up-to-date when this happens. For interoperability,
the argument should start with the extension name (sans -osc) or some
other suitable prefix, and a semicolon, to distinguish it from commands
for other extensions.

For example, C<overlay-osc> uses this:

   sub on_osc_seq_perl {
      my ($self, $osc, $resp) = @_;

      return unless $osc =~ s/^overlay;//;

      ... process remaining $osc string
   }

Be careful not ever to trust (in a security sense) the data you receive,
as its source can not easily be controlled (e-mail content, messages from
other users on the same system etc.).

For responses, C<$resp> contains the end-of-args separator used by the
sender.

=item on_add_lines $term, $string

Called whenever text is about to be output, with the text as argument. You
can filter/change and output the text yourself by returning a true value
and calling C<< $term->scr_add_lines >> yourself. Please note that this
might be very slow, however, as your hook is called for B<all> text being
output.

=item on_tt_write $term, $octets

Called whenever some data is written to the tty/pty and can be used to
suppress or filter tty input.

=item on_tt_paste $term, $octets

Called whenever text is about to be pasted, with the text as argument. You
can filter/change and paste the text yourself by returning a true value
and calling C<< $term->tt_paste >> yourself. C<$octets> is
locale-encoded.

=item on_line_update $term, $row

Called whenever a line was updated or changed. Can be used to filter
screen output (e.g. underline urls or other useless stuff). Only lines
that are being shown will be filtered, and, due to performance reasons,
not always immediately.

The row number is always the topmost row of the line if the line spans
multiple rows.

Please note that, if you change the line, then the hook might get called
later with the already-modified line (e.g. if unrelated parts change), so
you cannot just toggle rendition bits, but only set them.

=item on_refresh_begin $term

Called just before the screen gets redrawn. Can be used for overlay or
similar effects by modifying the terminal contents in refresh_begin, and
restoring them in refresh_end. The built-in overlay and selection display
code is run after this hook, and takes precedence.

=item on_refresh_end $term

Called just after the screen gets redrawn. See C<on_refresh_begin>.

=item on_action $term, $string

Called whenever an action is invoked for the corresponding extension
(e.g. via a C<extension:string> builtin action bound to a key, see
description of the B<keysym> resource in the urxvt(1) manpage). The
event is simply the action string. Note that an action event is always
associated to a single extension.

=item on_user_command $term, $string *DEPRECATED*

Called whenever a user-configured event is being activated (e.g. via
a C<perl:string> action bound to a key, see description of the B<keysym>
resource in the urxvt(1) manpage).

The event is simply the action string. This interface is going away in
preference to the C<on_action> hook.

=item on_resize_all_windows $term, $new_width, $new_height

Called just after the new window size has been calculated, but before
windows are actually being resized or hints are being set. If this hook
returns a true value, setting of the window hints is being skipped.

=item on_x_event $term, $event

Called on every X event received on the vt window (and possibly other
windows). Should only be used as a last resort. Most event structure
members are not passed.

=item on_root_event $term, $event

Like C<on_x_event>, but is called for events on the root window.

=item on_focus_in $term

Called whenever the window gets the keyboard focus, before rxvt-unicode
does focus in processing.

=item on_focus_out $term

Called whenever the window loses keyboard focus, before rxvt-unicode does
focus out processing.

=item on_configure_notify $term, $event

=item on_property_notify $term, $event

=item on_key_press $term, $event, $keysym, $octets

=item on_key_release $term, $event, $keysym

=item on_button_press $term, $event

=item on_button_release $term, $event

=item on_motion_notify $term, $event

=item on_map_notify $term, $event

=item on_unmap_notify $term, $event

Called whenever the corresponding X event is received for the terminal. If
the hook returns true, then the event will be ignored by rxvt-unicode.

The event is a hash with most values as named by Xlib (see the XEvent
manpage), with the additional members C<row> and C<col>, which are the
(real, not screen-based) row and column under the mouse cursor.

C<on_key_press> additionally receives the string rxvt-unicode would
output, if any, in locale-specific encoding.

=item on_client_message $term, $event

=item on_wm_protocols $term, $event

=item on_wm_delete_window $term, $event

Called when various types of ClientMessage events are received (all with
format=32, WM_PROTOCOLS or WM_PROTOCOLS:WM_DELETE_WINDOW).

=item on_bell $term

Called on receipt of a bell character.

=back

=cut

package urxvt;

use utf8;
use strict qw(vars subs);
use Carp ();
use Scalar::Util ();
use List::Util ();

our $VERSION = 1;
our $TERM;
our @TERM_INIT; # should go, prevents async I/O etc.
our @TERM_EXT;  # should go, prevents async I/O etc.
our @HOOKNAME;
our %HOOKTYPE = map +($HOOKNAME[$_] => $_), 0..$#HOOKNAME;
our %OPTION;

our $LIBDIR;
our $RESNAME;
our $RESCLASS;
our $RXVTNAME;

our $NOCHAR = chr 0xffff;

=head2 Variables in the C<urxvt> Package

=over

=item $urxvt::LIBDIR

The rxvt-unicode library directory, where, among other things, the perl
modules and scripts are stored.

=item $urxvt::RESCLASS, $urxvt::RESCLASS

The resource class and name rxvt-unicode uses to look up X resources.

=item $urxvt::RXVTNAME

The basename of the installed binaries, usually C<urxvt>.

=item $urxvt::TERM

The current terminal. This variable stores the current C<urxvt::term>
object, whenever a callback/hook is executing.

=item @urxvt::TERM_INIT

All code references in this array will be called as methods of the next newly
created C<urxvt::term> object (during the C<on_init> phase). The array
gets cleared before the code references that were in it are being executed,
so references can push themselves onto it again if they so desire.

This complements to the perl-eval command line option, but gets executed
first.

=item @urxvt::TERM_EXT

Works similar to C<@TERM_INIT>, but contains perl package/class names, which
get registered as normal extensions after calling the hooks in C<@TERM_INIT>
but before other extensions. Gets cleared just like C<@TERM_INIT>.

=back

=head2 Functions in the C<urxvt> Package

=over

=item urxvt::fatal $errormessage

Fatally aborts execution with the given error message (which should
include a trailing newline). Avoid at all costs! The only time this
is acceptable (and useful) is in the init hook, where it prevents the
terminal from starting up.

=item urxvt::warn $string

Calls C<rxvt_warn> with the given string which should include a trailing
newline. The module also overwrites the C<warn> builtin with a function
that calls this function.

Using this function has the advantage that its output ends up in the
correct place, e.g. on stderr of the connecting urxvtc client.

Messages have a size limit of 1023 bytes currently.

=item @terms = urxvt::termlist

Returns all urxvt::term objects that exist in this process, regardless of
whether they are started, being destroyed etc., so be careful. Only term
objects that have perl extensions attached will be returned (because there
is no urxvt::term object associated with others).

=item $time = urxvt::NOW

Returns the "current time" (as per the event loop).

=item urxvt::CurrentTime

=item urxvt::ShiftMask, LockMask, ControlMask, Mod1Mask, Mod2Mask,
Mod3Mask, Mod4Mask, Mod5Mask, Button1Mask, Button2Mask, Button3Mask,
Button4Mask, Button5Mask, AnyModifier

=item urxvt::NoEventMask, KeyPressMask, KeyReleaseMask,
ButtonPressMask, ButtonReleaseMask, EnterWindowMask, LeaveWindowMask,
PointerMotionMask, PointerMotionHintMask, Button1MotionMask, Button2MotionMask,
Button3MotionMask, Button4MotionMask, Button5MotionMask, ButtonMotionMask,
KeymapStateMask, ExposureMask, VisibilityChangeMask, StructureNotifyMask,
ResizeRedirectMask, SubstructureNotifyMask, SubstructureRedirectMask,
FocusChangeMask, PropertyChangeMask, ColormapChangeMask, OwnerGrabButtonMask

=item urxvt::KeyPress, KeyRelease, ButtonPress, ButtonRelease, MotionNotify,
EnterNotify, LeaveNotify, FocusIn, FocusOut, KeymapNotify, Expose,
GraphicsExpose, NoExpose, VisibilityNotify, CreateNotify, DestroyNotify,
UnmapNotify, MapNotify, MapRequest, ReparentNotify, ConfigureNotify,
ConfigureRequest, GravityNotify, ResizeRequest, CirculateNotify,
CirculateRequest, PropertyNotify, SelectionClear, SelectionRequest,
SelectionNotify, ColormapNotify, ClientMessage, MappingNotify

Various constants for use in X calls and event processing.

=item urxvt::PrivMode_132, PrivMode_132OK, PrivMode_rVideo, PrivMode_relOrigin,
PrivMode_Screen, PrivMode_Autowrap, PrivMode_aplCUR, PrivMode_aplKP,
PrivMode_HaveBackSpace, PrivMode_BackSpace, PrivMode_ShiftKeys,
PrivMode_VisibleCursor, PrivMode_MouseX10, PrivMode_MouseX11,
PrivMode_scrollBar, PrivMode_TtyOutputInh, PrivMode_Keypress,
PrivMode_smoothScroll, PrivMode_vt52, PrivMode_LFNL, PrivMode_MouseBtnEvent,
PrivMode_MouseAnyEvent, PrivMode_BracketPaste, PrivMode_ExtMouseUTF8,
PrivMode_ExtMouseUrxvt, PrivMode_BlinkingCursor, PrivMode_mouse_report,
PrivMode_Default

Constants for checking DEC private modes.

=back

=head2 RENDITION

Rendition bitsets contain information about colour, font, font styles and
similar information for each screen cell.

The following "macros" deal with changes in rendition sets. You should
never just create a bitset, you should always modify an existing one,
as they contain important information required for correct operation of
rxvt-unicode.

=over

=item $rend = urxvt::DEFAULT_RSTYLE

Returns the default rendition, as used when the terminal is starting up or
being reset. Useful as a base to start when creating renditions.

=item $rend = urxvt::OVERLAY_RSTYLE

Return the rendition mask used for overlays by default.

=item $rendbit = urxvt::RS_Bold, urxvt::RS_Italic, urxvt::RS_Blink,
urxvt::RS_RVid, urxvt::RS_Uline

Return the bit that enabled bold, italic, blink, reverse-video and
underline, respectively. To enable such a style, just logically OR it into
the bitset.

=item $foreground = urxvt::GET_BASEFG $rend

=item $background = urxvt::GET_BASEBG $rend

Return the foreground/background colour index, respectively.

=item $rend = urxvt::SET_FGCOLOR $rend, $new_colour

=item $rend = urxvt::SET_BGCOLOR $rend, $new_colour

=item $rend = urxvt::SET_COLOR $rend, $new_fg, $new_bg

Replace the foreground/background colour in the rendition mask with the
specified one.

=item $value = urxvt::GET_CUSTOM $rend

Return the "custom" value: Every rendition has 5 bits for use by
extensions. They can be set and changed as you like and are initially
zero.

=item $rend = urxvt::SET_CUSTOM $rend, $new_value

Change the custom value.

=back

=cut

BEGIN {
   # overwrite perl's warn
   *CORE::GLOBAL::warn = sub {
      my $msg = join "", @_;
      $msg .= "\n"
         unless $msg =~ /\n$/;
      urxvt::warn ($msg);
   };
}

no warnings 'utf8';

sub parse_resource {
   my ($term, $name, $isarg, $longopt, $flag, $value) = @_;

   $term->scan_extensions;

   # iterating over all resources has quadratic time overhead
   # overall, maybe this could be optimised?
   my $r = $term->{meta}{resource};
   keys %$r; # reset iterator
   while (my ($k, $v) = each %$r) {
      my $pattern = $k;
      $pattern =~ y/./-/ if $isarg;
      my $prefix = $name;
      my $suffix;
      if ($pattern =~ /\-$/) {
         $prefix = substr $name, 0, length $pattern;
         $suffix = substr $name, length $pattern;
      }
      if ($pattern eq $prefix) {
         $name = "$urxvt::RESCLASS.$k$suffix";

         push @{ $term->{perl_ext_3} }, $v->[0];

         return 1 unless $isarg;

         if ($v->[1] eq "boolean") {
            $term->put_option_db ($name, $flag ? "true" : "false");
            return 1;
         } else {
            $term->put_option_db ($name, $value);
            return 1 + 2;
         }
      }
   }

   0
}

sub usage {
   my ($term, $usage_type) = @_;

   $term->scan_extensions;

   my $r = $term->{meta}{resource};

   for my $pattern (sort keys %$r) {
      my ($ext, $type, $desc) = @{ $r->{$pattern} };

      $desc .= " (-pe $ext)";

      if ($usage_type == 1) {
         $pattern =~ y/./-/;
         $pattern =~ s/-$/-.../g;

         if ($type eq "boolean") {
            urxvt::log sprintf "  -%-30s %s\n", "/+$pattern", $desc;
         } else {
            urxvt::log sprintf "  -%-30s %s\n", "$pattern $type", $desc;
         }
      } else {
         $pattern =~ s/\.$/.*/g;
         urxvt::log sprintf "  %-31s %s\n", "$pattern:", $type;
      }
   }
}

my $verbosity = $ENV{URXVT_PERL_VERBOSITY} // 2;

sub verbose {
   my ($level, $msg) = @_;
   warn "$msg\n" if $level <= $verbosity;
}

my %extension_pkg;

# load a single script into its own package, once only
sub extension_package($) {
   my ($path) = @_;

   $extension_pkg{$path} ||= do {
      $path =~ /([^\/\\]+)$/;
      my $pkg = $1;
      $pkg =~ s/[^[:word:]]/_/g;
      $pkg = "urxvt::ext::$pkg";

      verbose 3, "loading extension '$path' into package '$pkg'";

      (${"$pkg\::_NAME"} = $path) =~ s/^.*[\\\/]//; # hackish

      open my $fh, "<:raw", $path
         or die "$path: $!";

      my $source =
         "package $pkg; use strict qw(vars subs); use utf8; no warnings 'utf8';\n"
         . "#line 1 \"$path\"\n{\n"
         . (do { local $/; <$fh> })
         . "\n};\n1";

      eval $source
         or die "$path: $@";

      $pkg
   }
}

our $retval; # return value for urxvt

# called by the rxvt core
sub invoke {
   local $TERM = shift;
   my $htype = shift;

   if ($htype == HOOK_INIT) {
      $TERM->scan_extensions;

      my %ext_arg;

      {
         my @init = @TERM_INIT;
         @TERM_INIT = ();
         $_->($TERM) for @init;
         my @pkg = @TERM_EXT;
         @TERM_EXT = ();
         $TERM->register_package ($_) for @pkg;
      }

      for (
         @{ delete $TERM->{perl_ext_3} },
         (grep $_, map { split /,/, $TERM->resource ("perl_ext_$_") } 1, 2),
      ) {
         if ($_ eq "default") {

            $ext_arg{$_} = []
               for qw(selection option-popup selection-popup readline searchable-scrollback confirm-paste);

            for ($TERM->_keysym_resources) {
               next if /^(?:string|command|builtin|builtin-string|perl)/;
               next unless /^([A-Za-z0-9_\-]+):/;

               my $ext = $1;

               $ext_arg{$ext} = [];
            }

         } elsif (/^-(.*)$/) { # remove from set
            delete $ext_arg{$1};

         } elsif (/^\/(.*)$/) { # prohibit loading
            undef $TERM->{ext_prohibit}{$1};

         } elsif (/^([^<]+)(?:<(.*)>)?$/) { # add to set, clear prohibit status
            delete $TERM->{ext_prohibit}{$1};
            push @{ $ext_arg{$1} }, defined $2 ? $2 : ();

         } else {
            verbose 2, "cannot parse extension specification '$_', ignoring.";
         }
      }

      $TERM->set_should_invoke (HOOK_OSC_SEQ     , +1) if $TERM->{meta}{autoload_osc};
      $TERM->set_should_invoke (HOOK_OSC_SEQ_PERL, +1) if $TERM->{meta}{autoload_osc_perl};

      for my $ext (sort keys %ext_arg) {
         my $path = $TERM->extension_path ($ext);

         if (defined $path) {
            $TERM->autoload_extension ($ext, $ext_arg{$ext});
         } else {
            verbose 2, "perl extension '$ext' not found in perl library search path";
         }
      }

      eval "#line 1 \"--perl-eval resource/argument\"\n" . $TERM->resource ("perl_eval");
      warn $@ if $@;
   }

   if ($htype == HOOK_OSC_SEQ) {
      if (my $exts = delete $TERM->{meta}{autoload_osc}{$_[0]}) {
         $TERM->autoload_extension ($_->[0]) for @$exts;
      }
   } elsif ($htype == HOOK_OSC_SEQ_PERL) {
      if ($_[0] =~ /^([^;]+)/ and (my $exts = delete $TERM->{meta}{autoload_osc_perl}{$1})) {
         $TERM->autoload_extension ($_->[0]) for @$exts;
      }
   }

   $retval = undef;

   if (my $cb = $TERM->{_hook}[$htype]) {
      verbose 10, "$HOOKNAME[$htype] (" . (join ", ", $TERM, @_) . ")"
         if $verbosity >= 10;

      if ($htype == HOOK_ACTION) {
         # this hook is only sent to the extension with the name
         # matching the first arg
         my $pkg = shift;
         $pkg =~ y/-/_/;
         $pkg = "urxvt::ext::$pkg";

         $cb = $cb->{$pkg}
            or return undef; #TODO: maybe warn user?

         $cb = { $pkg => $cb };
      }

      for my $pkg (keys %$cb) {
         my $retval_ = eval { $cb->{$pkg}->($TERM->{_pkg}{$pkg} || $TERM, @_) };
         $retval ||= $retval_;

         if ($@) {
            $TERM->ungrab; # better to lose the grab than the session
            warn $@;
         }
      }

      verbose 11, "$HOOKNAME[$htype] returning <$retval>"
         if $verbosity >= 11;
   }

   if ($htype == HOOK_DESTROY) {
      # clear package objects
      %$_ = () for values %{ $TERM->{_pkg} };

      # clear package
      %$TERM = ();
   }

   $retval
}

sub SET_COLOR($$$) {
   SET_BGCOLOR (SET_FGCOLOR ($_[0], $_[1]), $_[2])
}

sub rend2mask {
   no strict 'refs';
   my ($str, $mask) = (@_, 0);
   my %color = ( fg => undef, bg => undef );
   my @failed;
   for my $spec ( split /\s+/, $str ) {
      if ( $spec =~ /^([fb]g)[_:-]?(\d+)/i ) {
         $color{lc($1)} = $2;
      } else {
         my $neg = $spec =~ s/^[-^]//;
         unless ( exists &{"RS_$spec"} ) {
            push @failed, $spec;
            next;
         }
         my $cur = &{"RS_$spec"};
         if ( $neg ) {
            $mask &= ~$cur;
         } else {
            $mask |= $cur;
         }
      }
   }
   ($mask, @color{qw(fg bg)}, \@failed)
}

package urxvt::term::extension;

=head2 The C<urxvt::term::extension> class

Each extension attached to a terminal object is represented by
a C<urxvt::term::extension> object.

You can use these objects, which are passed to all callbacks to store any
state related to the terminal and extension instance.

The methods (And data members) documented below can be called on extension
objects, in addition to call methods documented for the <urxvt::term>
class.

=over

=item $urxvt_term = $self->{term}

Returns the C<urxvt::term> object associated with this instance of the
extension. This member I<must not> be changed in any way.

=cut

our $AUTOLOAD;

sub AUTOLOAD {
   $AUTOLOAD =~ /:([^:]+)$/
      or die "FATAL: \$AUTOLOAD '$AUTOLOAD' unparsable";

   eval qq{
      sub $AUTOLOAD {
         my \$proxy = shift;
         \$proxy->{term}->$1 (\@_)
      }
      1
   } or die "FATAL: unable to compile method forwarder: $@";

   goto &$AUTOLOAD;
}

sub DESTROY {
   # nop
}

# urxvt::destroy_hook (basically a cheap Guard:: implementation)

sub urxvt::destroy_hook::DESTROY {
   ${$_[0]}->();
}

sub urxvt::destroy_hook(&) {
   bless \shift, urxvt::destroy_hook::
}

=item $self->enable ($hook_name => $cb[, $hook_name => $cb..])

Dynamically enable the given hooks (named without the C<on_> prefix) for
this extension, replacing any hook previously installed via C<enable> in
this extension.

This is useful when you want to overwrite time-critical hooks only
temporarily.

To install additional callbacks for the same hook, you can use the C<on>
method of the C<urxvt::term> class.

=item $self->disable ($hook_name[, $hook_name..])

Dynamically disable the given hooks.

=cut

sub enable {
   my ($self, %hook) = @_;
   my $pkg = $self->{_pkg};

   while (my ($name, $cb) = each %hook) {
      my $htype = $HOOKTYPE{uc $name};
      defined $htype
         or Carp::croak "unsupported hook type '$name'";

      $self->set_should_invoke ($htype, +1)
         unless exists $self->{term}{_hook}[$htype]{$pkg};

      $self->{term}{_hook}[$htype]{$pkg} = $cb;
   }
}

sub disable {
   my ($self, @hook) = @_;
   my $pkg = $self->{_pkg};

   for my $name (@hook) {
      my $htype = $HOOKTYPE{uc $name};
      defined $htype
         or Carp::croak "unsupported hook type '$name'";

      $self->set_should_invoke ($htype, -1)
         if delete $self->{term}{_hook}[$htype]{$pkg};
   }
}

=item $guard = $self->on ($hook_name => $cb[, $hook_name => $cb..])

Similar to the C<enable> enable, but installs additional callbacks for
the given hook(s) (that is, it doesn't replace existing callbacks), and
returns a guard object. When the guard object is destroyed the callbacks
are disabled again.

=cut

sub urxvt::extension::on_disable::DESTROY {
   my $disable = shift;

   my $term = delete $disable->{""};

   while (my ($htype, $id) = each %$disable) {
      delete $term->{_hook}[$htype]{$id};
      $term->set_should_invoke ($htype, -1);
   }
}

sub on {
   my ($self, %hook) = @_;

   my $term = $self->{term};

   my %disable = ( "" => $term );

   while (my ($name, $cb) = each %hook) {
      my $htype = $HOOKTYPE{uc $name};
      defined $htype
         or Carp::croak "unsupported hook type '$name'";

      $term->set_should_invoke ($htype, +1);
      $term->{_hook}[$htype]{ $disable{$htype} = $cb+0 }
         = sub { shift; $cb->($self, @_) }; # very ugly indeed
   }

   bless \%disable, "urxvt::extension::on_disable"
}

=item $self->bind_action ($hotkey, $action)

=item $self->x_resource ($pattern)

=item $self->x_resource_boolean ($pattern)

These methods support an additional C<%> prefix for C<$action> or
C<$pattern> when called on an extension object, compared to the
C<urxvt::term> methods of the same name - see the description of these
methods in the C<urxvt::term> class for details.

=cut

sub bind_action {
   my ($self, $hotkey, $action) = @_;
   $action =~ s/^%:/$_[0]{_name}:/;
   $self->{term}->bind_action ($hotkey, $action)
}

sub x_resource {
   my ($self, $name) = @_;
   $name =~ s/^%(\.|$)/$_[0]{_name}$1/;
   $self->{term}->x_resource ($name)
}

sub x_resource_boolean {
   my ($self, $name) = @_;
   $name =~ s/^%(\.|$)/$_[0]{_name}$1/;
   $self->{term}->x_resource_boolean ($name)
}

=back

=cut

package urxvt::anyevent;

=head2 The C<urxvt::anyevent> Class

The sole purpose of this class is to deliver an interface to the
C<AnyEvent> module - any module using it will work inside urxvt without
further programming. The only exception is that you cannot wait on
condition variables, but non-blocking condvar use is ok.

In practical terms this means is that you cannot use blocking APIs, but
the non-blocking variant should work.

=cut

our $VERSION = '5.23';

$INC{"urxvt/anyevent.pm"} = 1; # mark us as there
push @AnyEvent::REGISTRY, [urxvt => urxvt::anyevent::];

sub timer {
   my ($class, %arg) = @_;

   my $cb = $arg{cb};

   urxvt::timer
      ->new
      ->after ($arg{after}, $arg{interval})
      ->cb ($arg{interval} ? $cb : sub {
        $_[0]->stop; # need to cancel manually
        $cb->();
      })
}

sub io {
   my ($class, %arg) = @_;

   my $cb = $arg{cb};
   my $fd = fileno $arg{fh};
   defined $fd or $fd = $arg{fh};

   bless [$arg{fh}, urxvt::iow
             ->new
             ->fd ($fd)
             ->events (($arg{poll} =~ /r/ ? 1 : 0)
                     | ($arg{poll} =~ /w/ ? 2 : 0))
             ->start
             ->cb ($cb)
         ], urxvt::anyevent::
}

sub idle {
   my ($class, %arg) = @_;

   my $cb = $arg{cb};

   urxvt::iw
      ->new
      ->start
      ->cb ($cb)
}

sub child {
   my ($class, %arg) = @_;

   my $cb = $arg{cb};

   urxvt::pw
      ->new
      ->start ($arg{pid})
      ->cb (sub {
        $_[0]->stop; # need to cancel manually
        $cb->($_[0]->rpid, $_[0]->rstatus);
      })
}

sub DESTROY {
   $_[0][1]->stop;
}

# only needed for AnyEvent < 6 compatibility
sub one_event {
   Carp::croak "AnyEvent->one_event blocking wait unsupported in urxvt, use a non-blocking API";
}

package urxvt::term;

=head2 The C<urxvt::term> Class

=over

=cut

# find on_xxx subs in the package and register them
# as hooks
sub register_package {
   my ($self, $pkg, $argv) = @_;

   return if $self->{_pkg}{$pkg};

   no strict 'refs';

   urxvt::verbose 6, "register package $pkg to $self";

   @{"$pkg\::ISA"} = urxvt::term::extension::;

   my $proxy = bless {
      _pkg  => $pkg,
      _name => ${"$pkg\::_NAME"}, # hackish
      argv  => $argv,
   }, $pkg;
   Scalar::Util::weaken ($proxy->{term} = $self);

   $self->{_pkg}{$pkg} = $proxy;

   for my $name (@HOOKNAME) {
      if (my $ref = $pkg->can ("on_" . lc $name)) {
         $proxy->enable ($name => $ref);
      }
   }

   if (my $attach_hook = $pkg->can ("on_attach")) {
      $attach_hook->($proxy)
         or urxvt::verbose 1, "$pkg->on_attach returned false, extension failed to attach";
   }
}

# map extension name to filesystem path
sub extension_path {
   (grep -f $_, map "$_/$_[1]", $_[0]->perl_libdirs)[0]
}

# load an extension by name
sub load_extension_file {
   my ($self, $path, $argv) = @_;

   $self->register_package (urxvt::extension_package $path, $argv);
}

# autoload an extension unless loading it is prohibited
sub autoload_extension {
   my ($self, $name, $argv) = @_;

   return if exists $self->{ext_prohibit}{$name};

   my $path = $self->extension_path ($name)
      // return urxvt::verbose 2, "perl extension '$name' not found in perl library search path (during autoload)";

   $self->load_extension_file ($path, $argv);
}

sub perl_libdirs {
   map { split /:/ }
      $_[0]->resource ("perl_lib"),
      $ENV{URXVT_PERL_LIB},
      "$ENV{HOME}/.urxvt/ext",
      "$LIBDIR/perl"
}

# scan for available extensions and collect their metadata
sub scan_extensions {
   my ($self) = @_;

   return if exists $self->{meta};

   my @urxvtdirs = perl_libdirs $self;
#   my @cpandirs = grep -d, map "$_/URxvt/Ext", @INC;

   $self->{meta} = \my %allmeta;

   # first gather extensions

   my $gather = sub {
      my ($dir, $core) = @_;

      opendir my $fh, $dir
         or return;

      for my $ext (readdir $fh) {
         $ext !~ /^\./
            or next;

         open my $fh, "<", "$dir/$ext"
            or next;

         -f $fh
            or next;

         $ext =~ s/\.uext$// or $core
            or next;

         my %meta = (dir => $dir);

         while (<$fh>) {
            if (/^#:META:(?:X_)?RESOURCE:(.*)/) {
               my ($pattern, $type, $desc) = split /:/, $1;
               $pattern =~ s/^%(\.|$)/$ext$1/g; # % in pattern == extension name
               if ($pattern =~ /[^a-zA-Z0-9\-\.]/) {
                  warn "$dir/$ext: meta resource '$pattern' contains illegal characters (not alphanumeric nor . nor *)\n";
               } else {
                  $meta{resource}{$pattern} = [$ext, $type, $desc];
               }

            } elsif (/^#:META:OSC:([0-9]+):(.*)/) {
               push @{$allmeta{autoload_osc}{$1}}, [$ext, $2];

            } elsif (/^#:META:OSC_PERL:([^:]+):(.*)/) {
               push @{$allmeta{autoload_osc_perl}{$1}}, [$ext, $2];

            } elsif (/^\s*(?:#|$)/) {
               # skip other comments and empty lines

            } else {
               last; # stop parsing on first non-empty non-comment line
            }
         }

         $allmeta{ext}{$ext} = \%meta;
      }
   };

#   $gather->($_, 0) for @cpandirs;
   $gather->($_, 1) for @urxvtdirs;

   # and now merge resources

   $allmeta{resource} = \my %resource;

   while (my ($k, $v) = each %{ $allmeta{ext} }) {
      #TODO: should check for extensions overriding each other
      %resource = (%resource, %{ $v->{resource} });
   }
}

=item $term = new urxvt::term $envhashref, $rxvtname, [arg...]

Creates a new terminal, very similar as if you had started it with system
C<$rxvtname, arg...>. C<$envhashref> must be a reference to a C<%ENV>-like
hash which defines the environment of the new terminal.

Croaks (and probably outputs an error message) if the new instance
couldn't be created.  Returns C<undef> if the new instance didn't
initialise perl, and the terminal object otherwise. The C<init> and
C<start> hooks will be called before this call returns, and are free to
refer to global data (which is race free).

=cut

sub new {
   my ($class, $env, @args) = @_;

   $env  or Carp::croak "environment hash missing in call to urxvt::term->new";
   @args or Carp::croak "name argument missing in call to urxvt::term->new";

   _new ([ map "$_=$env->{$_}", keys %$env ], \@args);
}

=item $term->destroy

Destroy the terminal object (close the window, free resources
etc.). Please note that urxvt will not exit as long as any event
watchers (timers, io watchers) are still active.

=item $term->exec_async ($cmd[, @args])

Works like the combination of the C<fork>/C<exec> builtins, which executes
("starts") programs in the background. This function takes care of setting
the user environment before exec'ing the command (e.g. C<PATH>) and should
be preferred over explicit calls to C<exec> or C<system>.

Returns the pid of the subprocess or C<undef> on error.

=cut

sub exec_async {
   my $self = shift;

   my $pid = fork;

   return $pid
      if !defined $pid or $pid;

   %ENV = %{ $self->env };

   exec @_;
   urxvt::_exit 255;
}

=item $isset = $term->option ($optval[, $set])

Returns true if the option specified by C<$optval> is enabled, and
optionally change it. All option values are stored by name in the hash
C<%urxvt::OPTION>. Options not enabled in this binary are not in the hash.

Here is a likely non-exhaustive list of option names, please see the
source file F</src/optinc.h> to see the actual list:

 borderLess buffered console cursorBlink cursorUnderline hold iconic
 insecure intensityStyles iso14755 iso14755_52 jumpScroll loginShell
 mapAlert meta8 mouseWheelScrollPage override_redirect pastableTabs
 pointerBlank reverseVideo scrollBar scrollBar_floating scrollBar_right
 scrollTtyKeypress scrollTtyOutput scrollWithBuffer secondaryScreen
 secondaryScroll skipBuiltinGlyphs skipScroll transparent tripleclickwords
 urgentOnBell utmpInhibit visualBell disablePasteBrackets

=item $value = $term->resource ($name[, $newval])

Returns the current resource value associated with a given name and
optionally sets a new value. Setting values is most useful in the C<init>
hook. Unset resources are returned and accepted as C<undef>.

The new value must be properly encoded to a suitable character encoding
before passing it to this method. Similarly, the returned value may need
to be converted from the used encoding to text.

Resource names are as defined in F<src/rsinc.h>. Colours can be specified
as resource names of the form C<< color+<index> >>, e.g. C<color+5>. (will
likely change).

Please note that resource strings will currently only be freed when the
terminal is destroyed, so changing options frequently will eat memory.

Here is a likely non-exhaustive list of resource names, not all of which
are supported in every build, please see the source file F</src/rsinc.h>
to see the actual list:

  answerbackstring backgroundPixmap backspace_key blurradius
  boldFont boldItalicFont borderLess buffered chdir color cursorBlink
  cursorUnderline cutchars delete_key depth display_name embed ext_bwidth
  fade font geometry hold iconName iconfile imFont imLocale inputMethod
  insecure int_bwidth intensityStyles iso14755 iso14755_52 italicFont
  jumpScroll letterSpace lineSpace loginShell mapAlert meta8 modifier
  mouseWheelScrollPage name override_redirect pastableTabs path perl_eval
  perl_ext_1 perl_ext_2 perl_lib pointerBlank pointerBlankDelay
  preeditType print_pipe pty_fd reverseVideo saveLines scrollBar
  scrollBar_align scrollBar_floating scrollBar_right scrollBar_thickness
  scrollTtyKeypress scrollTtyOutput scrollWithBuffer scrollstyle
  secondaryScreen secondaryScroll shade skipBuiltinGlyphs skipScroll
  term_name title transient_for transparent tripleclickwords urgentOnBell
  utmpInhibit visualBell rewrapMode disablePasteBrackets

=cut

sub resource($$;$) {
   my ($self, $name) = (shift, shift);
   unshift @_, $self, $name, ($name =~ s/\s*\+\s*(\d+)$// ? $1 : 0);
   goto &urxvt::term::_resource
}

=item $value = $term->x_resource ($pattern)

Returns the X-Resource for the given pattern, excluding the program or
class name, i.e.  C<< $term->x_resource ("boldFont") >> should return the
same value as used by this instance of rxvt-unicode. Returns C<undef> if no
resource with that pattern exists.

Extensions that define extra resources also need to call this method
to access their values.

If the method is called on an extension object (basically, from an
extension), then the special prefix C<%.> will be replaced by the name of
the extension and a dot, and the lone string C<%> will be replaced by the
extension name itself. This makes it possible to code extensions so you
can rename them and get a new set of resources without having to change
the actual code.

This method should only be called during the C<on_start> hook, as there is
only one resource database per display, and later invocations might return
the wrong resources.

=item $value = $term->x_resource_boolean ($pattern)

Like C<x_resource>, above, but interprets the string value as a boolean
and returns C<1> for true values, C<0> for false values and C<undef> if
the resource or option isn't specified.

You should always use this method to parse boolean resources.

=cut

sub x_resource_boolean {
   my $res = &x_resource;

   $res =~ /^\s*(?:true|yes|on|1)\s*$/i ? 1 : defined $res && 0
}

=item $action = $term->lookup_keysym ($keysym, $state)

Returns the action bound to key combination C<($keysym, $state)>,
if a binding for it exists, and C<undef> otherwise.

=item $success = $term->bind_action ($key, $action)

Adds a key binding exactly as specified via a C<keysym> resource. See the
C<keysym> resource in the urxvt(1) manpage.

To add default bindings for actions, an extension should call C<<
->bind_action >> in its C<init> hook for every such binding. Doing it
in the C<init> hook allows users to override or remove the binding
again.

Example: the C<searchable-scrollback> by default binds itself
on C<Meta-s>, using C<< $self->bind_action >>, which calls C<<
$term->bind_action >>.

   sub init {
      my ($self) = @_;

      $self->bind_action ("M-s" => "%:start");
   }

=item $rend = $term->rstyle ([$new_rstyle])

Return and optionally change the current rendition. Text that is output by
the terminal application will use this style.

=item ($row, $col) = $term->screen_cur ([$row, $col])

Return the current coordinates of the text cursor position and optionally
set it (which is usually bad as applications don't expect that).

=item ($row, $col) = $term->selection_mark ([$row, $col])

=item ($row, $col) = $term->selection_beg ([$row, $col])

=item ($row, $col) = $term->selection_end ([$row, $col])

Return the current values of the selection mark, begin or end positions.

When arguments are given, then the selection coordinates are set to
C<$row> and C<$col>, and the selection screen is set to the current
screen.

=item $screen = $term->selection_screen ([$screen])

Returns the current selection screen, and then optionally sets it.

=item $term->selection_make ($eventtime[, $rectangular])

Tries to make a selection as set by C<selection_beg> and
C<selection_end>. If C<$rectangular> is true (default: false), a
rectangular selection will be made. This is the preferred function to make
a selection.

=item $success = $term->selection_grab ($eventtime[, $clipboard])

Try to acquire ownership of the primary (clipboard if C<$clipboard> is
true) selection from the server. The corresponding text can be set
with the next method. No visual feedback will be given. This function
is mostly useful from within C<on_sel_grab> hooks.

=item $oldtext = $term->selection ([$newtext, $clipboard])

Return the current selection (clipboard if C<$clipboard> is true) text
and optionally replace it by C<$newtext>.

=item $term->selection_clear ([$clipboard])

Revoke ownership of the primary (clipboard if C<$clipboard> is true) selection.

=item $term->overlay_simple ($x, $y, $text)

Create a simple multi-line overlay box. See the next method for details.

=cut

sub overlay_simple {
   my ($self, $x, $y, $text) = @_;

   my @lines = split /\n/, $text;

   my $w = List::Util::max map $self->strwidth ($_), @lines;

   my $overlay = $self->overlay ($x, $y, $w, scalar @lines);
   $overlay->set (0, $_, $lines[$_]) for 0.. $#lines;

   $overlay
}

=item $term->overlay ($x, $y, $width, $height[, $rstyle[, $border]])

Create a new (empty) overlay at the given position with the given
width/height. C<$rstyle> defines the initial rendition style
(default: C<OVERLAY_RSTYLE>).

If C<$border> is C<2> (default), then a decorative border will be put
around the box.

If either C<$x> or C<$y> is negative, then this is counted from the
right/bottom side, respectively.

This method returns an urxvt::overlay object. The overlay will be visible
as long as the perl object is referenced.

The methods currently supported on C<urxvt::overlay> objects are:

=over

=item $overlay->set ($x, $y, $text[, $rend])

Similar to C<< $term->ROW_t >> and C<< $term->ROW_r >> in that it puts
text in rxvt-unicode's special encoding and an array of rendition values
at a specific position inside the overlay.

If C<$rend> is missing, then the rendition will not be changed.

=item $overlay->hide

If visible, hide the overlay, but do not destroy it.

=item $overlay->show

If hidden, display the overlay again.

=back

=item $popup = $term->popup ($event)

Creates a new C<urxvt::popup> object that implements a popup menu. The
C<$event> I<must> be the event causing the menu to pop up (a button event,
currently).

=cut

sub popup {
   my ($self, $event) = @_;

   $self->grab ($event->{time}, 1)
      or return;

   my $popup = bless {
      term  => $self,
      event => $event,
   }, urxvt::popup::;

   Scalar::Util::weaken $popup->{term};

   $self->{_destroy}{$popup} = urxvt::destroy_hook { $popup->{popup}->destroy };
   Scalar::Util::weaken $self->{_destroy}{$popup};

   $popup
}

=item $cellwidth = $term->strwidth ($string)

Returns the number of screen-cells this string would need. Correctly
accounts for wide and combining characters.

=item $octets = $term->locale_encode ($string)

Convert the given text string into the corresponding locale
encoding. Returns C<undef> if C<$string> is C<undef>.

=item $string = $term->locale_decode ($octets)

Convert the given locale-encoded octets into a perl string. Returns
C<undef> if C<$octets> is C<undef>.

=item $term->scr_xor_span ($beg_row, $beg_col, $end_row, $end_col[, $rstyle])

XORs the rendition values in the given span with the provided value
(default: C<RS_RVid>), which I<MUST NOT> contain font styles. Useful in
refresh hooks to provide effects similar to the selection.

=item $term->scr_xor_rect ($beg_row, $beg_col, $end_row, $end_col[, $rstyle1[, $rstyle2]])

Similar to C<scr_xor_span>, but xors a rectangle instead. Trailing
whitespace will additionally be xored with the C<$rstyle2>, which defaults
to C<RS_RVid | RS_Uline>, which removes reverse video again and underlines
it instead. Both styles I<MUST NOT> contain font styles.

=item $term->scr_bell

Ring the bell!

=item $term->scr_add_lines ($string)

Write the given text string to the screen, as if output by the application
running inside the terminal. It may not contain command sequences (escape
codes - see C<cmd_parse> for that), but is free to use line feeds,
carriage returns and tabs. The string is a normal text string, not in
locale-dependent encoding.

Normally its not a good idea to use this function, as programs might be
confused by changes in cursor position or scrolling. Its useful inside a
C<on_add_lines> hook, though.

=item $term->scr_change_screen ($screen)

Switch to given screen - 0 primary, 1 secondary.

=item $term->cmd_parse ($octets)

Similar to C<scr_add_lines>, but the argument must be in the
locale-specific encoding of the terminal and can contain command sequences
(escape codes) that will be interpreted.

=item $term->tt_write ($octets)

Write the octets given in C<$octets> to the tty (i.e. as user input
to the program, see C<cmd_parse> for the opposite direction). To pass
characters instead of octets, you should convert your strings first to the
locale-specific encoding using C<< $term->locale_encode >>.

=item $term->tt_write_user_input ($octets)

Like C<tt_write>, but should be used when writing strings in response to
the user pressing a key, to invoke the additional actions requested by
the user for that case (C<tt_write> doesn't do that).

The typical use case would be inside C<on_action> hooks.

=item $term->tt_paste ($octets)

Write the octets given in C<$octets> to the tty as a paste, converting NL to
CR and bracketing the data with control sequences if bracketed paste mode
is set.

=item $old_events = $term->pty_ev_events ([$new_events])

Replaces the event mask of the pty watcher by the given event mask. Can
be used to suppress input and output handling to the pty/tty. See the
description of C<< urxvt::timer->events >>. Make sure to always restore
the previous value.

=item $fd = $term->pty_fd

Returns the master file descriptor for the pty in use, or C<-1> if no pty
is used.

=item $windowid = $term->parent

Return the window id of the toplevel window.

=item $windowid = $term->vt

Return the window id of the terminal window.

=item $term->vt_emask_add ($x_event_mask)

Adds the specified events to the vt event mask. Useful e.g. when you want
to receive pointer events all the times:

   $term->vt_emask_add (urxvt::PointerMotionMask);

=item $term->set_urgency ($set)

Enable/disable the urgency hint on the toplevel window.

=item $term->focus_in

=item $term->focus_out

=item $term->key_press ($state, $keycode[, $time])

=item $term->key_release ($state, $keycode[, $time])

Deliver various fake events to to terminal.

=item $window_width = $term->width ([$new_value])

=item $window_height = $term->height ([$new_value])

=item $font_width = $term->fwidth ([$new_value])

=item $font_height = $term->fheight ([$new_value])

=item $font_ascent = $term->fbase ([$new_value])

=item $terminal_rows = $term->nrow ([$new_value])

=item $terminal_columns = $term->ncol ([$new_value])

=item $has_focus = $term->focus ([$new_value])

=item $is_mapped = $term->mapped ([$new_value])

=item $max_scrollback = $term->saveLines ([$new_value])

=item $nrow_plus_saveLines = $term->total_rows ([$new_value])

=item $topmost_scrollback_row = $term->top_row ([$new_value])

Return various integers describing terminal characteristics. If an
argument is given, changes the value and returns the previous one.

=item $x_display = $term->display_id

Return the DISPLAY used by rxvt-unicode.

=item $lc_ctype = $term->locale

Returns the LC_CTYPE category string used by this rxvt-unicode.

=item $env = $term->env

Returns a copy of the environment in effect for the terminal as a hashref
similar to C<\%ENV>.

=item @envv = $term->envv

Returns the environment as array of strings of the form C<VAR=VALUE>.

=item @argv = $term->argv

Return the argument vector as this terminal, similar to @ARGV, but
includes the program name as first element.

=cut

sub env {
   +{ map /^([^=]+)(?:=(.*))?$/s && ($1 => $2), $_[0]->envv }
}

=item $modifiermask = $term->ModLevel3Mask

=item $modifiermask = $term->ModMetaMask

=item $modifiermask = $term->ModNumLockMask

Return the modifier masks corresponding to the "ISO Level 3 Shift" (often
AltGr), the meta key (often Alt) and the num lock key, if applicable.

=item $screen = $term->current_screen

Returns the currently displayed screen (0 primary, 1 secondary).

=item $cursor_is_hidden = $term->hidden_cursor

Returns whether the cursor is currently hidden or not.

=item $priv_modes = $term->priv_modes

Returns a bitset with the state of DEC private modes.

Example:

  if ($term->priv_modes & urxvt::PrivMode_mouse_report) {
      # mouse reporting is turned on
  }

=item $view_start = $term->view_start ([$newvalue])

Returns the row number of the topmost displayed line and changes it,
if an argument is given. Values greater than or equal to C<0> display
the terminal contents. Lower values scroll this many lines into the
scrollback buffer.

=item $term->want_refresh

Requests a screen refresh. At the next opportunity, rxvt-unicode will
compare the on-screen display with its stored representation. If they
differ, it redraws the differences.

Used after changing terminal contents to display them.

=item $term->refresh_check

Checks if a refresh has been requested and, if so, schedules one.

=item $text = $term->ROW_t ($row_number[, $new_text[, $start_col]])

Returns the text of the entire row with number C<$row_number>. Row C<< $term->top_row >>
is the topmost terminal line, row C<< $term->nrow-1 >> is the bottommost
terminal line. Nothing will be returned if a nonexistent line
is requested.

If C<$new_text> is specified, it will replace characters in the current
line, starting at column C<$start_col> (default C<0>), which is useful
to replace only parts of a line. The font index in the rendition will
automatically be updated.

C<$text> is in a special encoding: tabs and wide characters that use more
than one cell when displayed are padded with C<$urxvt::NOCHAR> (chr 65535)
characters. Characters with combining characters and other characters that
do not fit into the normal text encoding will be replaced with characters
in the private use area.

You have to obey this encoding when changing text. The advantage is
that C<substr> and similar functions work on screen cells and not on
characters.

The methods C<< $term->special_encode >> and C<< $term->special_decode >>
can be used to convert normal strings into this encoding and vice versa.

=item $rend = $term->ROW_r ($row_number[, $new_rend[, $start_col]])

Like C<< $term->ROW_t >>, but returns an arrayref with rendition
bitsets. Rendition bitsets contain information about colour, font, font
styles and similar information. See also C<< $term->ROW_t >>.

When setting rendition, the font mask will be ignored.

See the section on RENDITION, above.

=item $length = $term->ROW_l ($row_number[, $new_length])

Returns the number of screen cells that are in use ("the line
length"). Unlike the urxvt core, this returns C<< $term->ncol >> if the
line is joined with the following one.

=item $bool = $term->is_longer ($row_number)

Returns true if the row is part of a multiple-row logical "line" (i.e.
joined with the following row), which means all characters are in use
and it is continued on the next row (and possibly a continuation of the
previous row(s)).

=item $line = $term->line ($row_number)

Create and return a new C<urxvt::line> object that stores information
about the logical line that row C<$row_number> is part of. It supports the
following methods:

=over

=item $text = $line->t ([$new_text])

Returns or replaces the full text of the line, similar to C<ROW_t>

=item $rend = $line->r ([$new_rend])

Returns or replaces the full rendition array of the line, similar to C<ROW_r>

=item $length = $line->l

Returns the length of the line in cells, similar to C<ROW_l>.

=item $rownum = $line->beg

=item $rownum = $line->end

Return the row number of the first/last row of the line, respectively.

=item $offset = $line->offset_of ($row, $col)

Returns the character offset of the given row|col pair within the logical
line. Works for rows outside the line, too, and returns corresponding
offsets outside the string.

=item ($row, $col) = $line->coord_of ($offset)

Translates a string offset into terminal coordinates again.

=back

=cut

sub line {
   my ($self, $row) = @_;

   my $maxrow = $self->nrow - 1;

   my ($beg, $end) = ($row, $row);

   --$beg while $self->ROW_is_longer ($beg - 1);
   ++$end while $self->ROW_is_longer ($end) && $end < $maxrow;

   bless {
      term => $self,
      beg  => $beg,
      end  => $end,
      ncol => $self->ncol,
      len  => ($end - $beg) * $self->ncol + $self->ROW_l ($end),
   }, urxvt::line::
}

sub urxvt::line::t {
   my ($self) = @_;

   if (@_ > 1) {
      $self->{term}->ROW_t ($_, $_[1], 0, ($_ - $self->{beg}) * $self->{ncol}, $self->{ncol})
         for $self->{beg} .. $self->{end};
   }

   defined wantarray &&
      substr +(join "", map $self->{term}->ROW_t ($_), $self->{beg} .. $self->{end}),
             0, $self->{len}
}

sub urxvt::line::r {
   my ($self) = @_;

   if (@_ > 1) {
      $self->{term}->ROW_r ($_, $_[1], 0, ($_ - $self->{beg}) * $self->{ncol}, $self->{ncol})
         for $self->{beg} .. $self->{end};
   }

   if (defined wantarray) {
      my $rend = [
         map @{ $self->{term}->ROW_r ($_) }, $self->{beg} .. $self->{end}
      ];
      $#$rend = $self->{len} - 1;
      return $rend;
   }

   ()
}

sub urxvt::line::beg { $_[0]{beg} }
sub urxvt::line::end { $_[0]{end} }
sub urxvt::line::l   { $_[0]{len} }

sub urxvt::line::offset_of {
   my ($self, $row, $col) = @_;

   ($row - $self->{beg}) * $self->{ncol} + $col
}

sub urxvt::line::coord_of {
   my ($self, $offset) = @_;

   use integer;

   (
      $offset / $self->{ncol} + $self->{beg},
      $offset % $self->{ncol}
   )
}

=item $text = $term->special_encode $string

Converts a perl string into the special encoding used by rxvt-unicode,
where one character corresponds to one screen cell. See
C<< $term->ROW_t >> for details.

=item $string = $term->special_decode $text

Converts rxvt-unicode's text representation into a perl string. See
C<< $term->ROW_t >> for details.

=item $success = $term->grab_button ($button, $modifiermask[, $window = $term->vt])

=item $term->ungrab_button ($button, $modifiermask[, $window = $term->vt])

Register/unregister a synchronous button grab. See the XGrabButton
manpage.

=item $success = $term->grab ($eventtime[, $sync])

Calls XGrabPointer and XGrabKeyboard in asynchronous (default) or
synchronous (C<$sync> is true). Also remembers the grab timestamp.

=item $term->allow_events_async

Calls XAllowEvents with AsyncBoth for the most recent grab.

=item $term->allow_events_sync

Calls XAllowEvents with SyncBoth for the most recent grab.

=item $term->allow_events_replay

Calls XAllowEvents with both ReplayPointer and ReplayKeyboard for the most
recent grab.

=item $term->ungrab

Calls XUngrabPointer and XUngrabKeyboard for the most recent grab. Is called automatically on
evaluation errors, as it is better to lose the grab in the error case as
the session.

=item $atom = $term->XInternAtom ($atom_name[, $only_if_exists])

=item $atom_name = $term->XGetAtomName ($atom)

=item @atoms = $term->XListProperties ($window)

=item ($type,$format,$octets) = $term->XGetWindowProperty ($window, $property)

=item $term->XChangeProperty ($window, $property, $type, $format, $octets)

=item $term->XDeleteProperty ($window, $property)

=item $window = $term->DefaultRootWindow

=item $term->XReparentWindow ($window, $parent, [$x, $y])

=item $term->XMapWindow ($window)

=item $term->XUnmapWindow ($window)

=item $term->XMoveResizeWindow ($window, $x, $y, $width, $height)

=item ($x, $y, $child_window) = $term->XTranslateCoordinates ($src, $dst, $x, $y)

=item $term->XChangeInput ($window, $add_events[, $del_events])

=item $keysym = $term->XStringToKeysym ($string)

=item $string = $term->XKeysymToString ($keysym)

Various X or X-related functions. The C<$term> object only serves as
the source of the display, otherwise those functions map more-or-less
directly onto the X functions of the same name.

=back

=cut

package urxvt::popup;

=head2 The C<urxvt::popup> Class

=over

=cut

sub add_item {
   my ($self, $item) = @_;

   $item->{rend}{normal} = "\x1b[0;30;47m" unless exists $item->{rend}{normal};
   $item->{rend}{hover}  = "\x1b[0;30;46m" unless exists $item->{rend}{hover};
   $item->{rend}{active} = "\x1b[m"        unless exists $item->{rend}{active};

   $item->{render} ||= sub { $_[0]{text} };

   push @{ $self->{item} }, $item;
}

=item $popup->add_title ($title)

Adds a non-clickable title to the popup.

=cut

sub add_title {
   my ($self, $title) = @_;

   $self->add_item ({
      rend => { normal => "\x1b[38;5;11;44m", hover => "\x1b[38;5;11;44m", active => "\x1b[38;5;11;44m" },
      text => $title,
      activate => sub { },
   });
}

=item $popup->add_separator ([$sepchr])

Creates a separator, optionally using the character given as C<$sepchr>.

=cut

sub add_separator {
   my ($self, $sep) = @_;

   $sep ||= "=";

   $self->add_item ({
      rend => { normal => "\x1b[0;30;47m", hover => "\x1b[0;30;47m", active => "\x1b[0;30;47m" },
      text => "",
      render => sub { $sep x $self->{term}->ncol },
      activate => sub { },
   });
}

=item $popup->add_button ($text, $cb)

Adds a clickable button to the popup. C<$cb> is called whenever it is
selected.

=cut

sub add_button {
   my ($self, $text, $cb) = @_;

   $self->add_item ({ type => "button", text => $text, activate => $cb});
}

=item $popup->add_toggle ($text, $initial_value, $cb)

Adds a toggle/checkbox item to the popup. The callback gets called
whenever it gets toggled, with a boolean indicating its new value as its
first argument.

=cut

sub add_toggle {
   my ($self, $text, $value, $cb) = @_;

   my $item; $item = {
      type => "button",
      text => "  $text",
      value => $value,
      render => sub { ($_[0]{value} ? "* " : "  ") . $text },
      activate => sub { $cb->($_[1]{value} = !$_[1]{value}); },
   };

   $self->add_item ($item);
}

=item $popup->show

Displays the popup (which is initially hidden).

=cut

sub show {
   my ($self) = @_;

   local $urxvt::popup::self = $self;

   my $env = $self->{term}->env;
   # we can't hope to reproduce the locale algorithm, so nuke LC_ALL and set LC_CTYPE.
   delete $env->{LC_ALL};
   $env->{LC_CTYPE} = $self->{term}->locale;

   my $term = urxvt::term->new (
      $env, "popup",
      "--perl-lib" => "", "--perl-ext-common" => "",
      "-pty-fd" => -1, "-sl" => 0,
      "-b" => 1, "-bd" => "grey80", "-bl", "-override-redirect",
      "--transient-for" => $self->{term}->parent,
      "-display" => $self->{term}->display_id,
      "-pe" => "urxvt-popup",
   ) or die "unable to create popup window\n";

   unless (delete $term->{urxvt_popup_init_done}) {
      $term->ungrab;
      $term->destroy;
      die "unable to initialise popup window\n";
   }
}

sub DESTROY {
   my ($self) = @_;

   delete $self->{term}{_destroy}{$self};
   $self->{term}->ungrab;
}

=back

=cut

package urxvt::watcher;

=head2 The C<urxvt::timer> Class

This class implements timer watchers/events. Time is represented as a
fractional number of seconds since the epoch. Example:

   $term->{overlay} = $term->overlay (-1, 0, 8, 1, urxvt::OVERLAY_RSTYLE, 0);
   $term->{timer} = urxvt::timer
                    ->new
                    ->interval (1)
                    ->cb (sub {
                       $term->{overlay}->set (0, 0,
                          sprintf "%2d:%02d:%02d", (localtime urxvt::NOW)[2,1,0]);
                    });

=over

=item $timer = new urxvt::timer

Create a new timer object in started state. It is scheduled to fire
immediately.

=item $timer = $timer->cb (sub { my ($timer) = @_; ... })

Set the callback to be called when the timer triggers.

=item $timer = $timer->set ($tstamp[, $interval])

Set the time the event is generated to $tstamp (and optionally specifies a
new $interval).

=item $timer = $timer->interval ($interval)

By default (and when C<$interval> is C<0>), the timer will automatically
stop after it has fired once. If C<$interval> is non-zero, then the timer
is automatically rescheduled at the given intervals.

=item $timer = $timer->start

Start the timer.

=item $timer = $timer->start ($tstamp[, $interval])

Set the event trigger time to C<$tstamp> and start the timer. Optionally
also replaces the interval.

=item $timer = $timer->after ($delay[, $interval])

Like C<start>, but sets the expiry timer to c<urxvt::NOW + $delay>.

=item $timer = $timer->stop

Stop the timer.

=back

=head2 The C<urxvt::iow> Class

This class implements io watchers/events. Example:

  $term->{socket} = ...
  $term->{iow} = urxvt::iow
                 ->new
                 ->fd (fileno $term->{socket})
                 ->events (urxvt::EV_READ)
                 ->start
                 ->cb (sub {
                   my ($iow, $revents) = @_;
                   # $revents must be 1 here, no need to check
                   sysread $term->{socket}, my $buf, 8192
                      or end-of-file;
                 });


=over

=item $iow = new urxvt::iow

Create a new io watcher object in stopped state.

=item $iow = $iow->cb (sub { my ($iow, $reventmask) = @_; ... })

Set the callback to be called when io events are triggered. C<$reventmask>
is a bitset as described in the C<events> method.

=item $iow = $iow->fd ($fd)

Set the file descriptor (not handle) to watch.

=item $iow = $iow->events ($eventmask)

Set the event mask to watch. The only allowed values are
C<urxvt::EV_READ> and C<urxvt::EV_WRITE>, which might be ORed
together, or C<urxvt::EV_NONE>.

=item $iow = $iow->start

Start watching for requested events on the given handle.

=item $iow = $iow->stop

Stop watching for events on the given file handle.

=back

=head2 The C<urxvt::iw> Class

This class implements idle watchers, that get called automatically when
the process is idle. They should return as fast as possible, after doing
some useful work.

=over

=item $iw = new urxvt::iw

Create a new idle watcher object in stopped state.

=item $iw = $iw->cb (sub { my ($iw) = @_; ... })

Set the callback to be called when the watcher triggers.

=item $timer = $timer->start

Start the watcher.

=item $timer = $timer->stop

Stop the watcher.

=back

=head2 The C<urxvt::pw> Class

This class implements process watchers. They create an event whenever a
process exits, after which they stop automatically.

   my $pid = fork;
   ...
   $term->{pw} = urxvt::pw
                    ->new
                    ->start ($pid)
                    ->cb (sub {
                       my ($pw, $exit_status) = @_;
                       ...
                    });

=over

=item $pw = new urxvt::pw

Create a new process watcher in stopped state.

=item $pw = $pw->cb (sub { my ($pw, $exit_status) = @_; ... })

Set the callback to be called when the timer triggers.

=item $pw = $timer->start ($pid)

Tells the watcher to start watching for process C<$pid>.

=item $pw = $pw->stop

Stop the watcher.

=back

=head1 ENVIRONMENT

=head2 URXVT_PERL_VERBOSITY

This variable controls the verbosity level of the perl extension. Higher
numbers indicate more verbose output.

=over

=item == 0 - fatal messages only

=item >= 2 - general warnings (default level)

=item >= 3 - script loading and management

=item >=10 - all called hooks

=item >=11 - hook return values

=back

=head1 AUTHOR

 Marc Lehmann <schmorp@schmorp.de>
 http://software.schmorp.de/pkg/rxvt-unicode

=cut

1

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