rxvt-unicode/src/urxvt.pm

=head1 NAME

rxvtperl - rxvt-unicode's embedded perl interpreter

=head1 SYNOPSIS

* Put your scripts into F<@@RXVT_LIBDIR@@/urxvt/perl-ext/>, they will be loaded automatically.

* Scripts are evaluated in a 'use strict' and 'use utf8' environment, and
thus must be encoded as UTF-8.

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

   1

=head1 DESCRIPTION

On startup, @@RXVT_NAME@@ will scan F<@@RXVT_LIBDIR@@/urxvt/perl-ext/>
for files and will load them. Everytime a terminal object gets created,
the directory specified by the C<perl-lib> resource will be additionally
scanned.

Each script will only ever be loaded once, even in @@RXVT_NAME@@d, where
scripts will be shared for all terminals.

Hooks in scripts specified by C<perl-lib> will only be called for the
terminals created with that specific option value.

=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. The only reserved member is C<_ptr>, which must not be changed.

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.

=head2 Hooks

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

All of them must return a boolean value. If it is true, then the event
counts as being I<consumed>, and the invocation of other hooks is skipped,
and the relevant action might not be carried out by the C++ code.

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

=over 4

=item on_init $term

Called after a new terminal object has been initialized, but before
windows are created or the command gets run.

=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_start $term

Called at the very end of initialisation of a new terminal, just before
returning to the mainloop.

=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 hilighted.

=item on_focus_in $term

Called whenever the window gets the keyboard focus, before urxvt does
focus in processing.

=item on_focus_out $term

Called wheneever the window loses keyboard focus, before urxvt does focus
out processing.

=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_tty_activity $term *NYI*

Called whenever the program(s) running in the urxvt window send output.

=item on_refresh_begin $term

Called just before the screen gets redrawn. Can be used for overlay
or similar effects by modify 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>.

=back

=head2 Functions in the C<urxvt> Package

=over 4

=item urxvt::fatal $errormessage

Fatally aborts execution with the given error message. Avoid at all
costs! The only time this is acceptable is when the terminal process
starts up.

=item urxvt::warn $string

Calls C<rxvt_warn> with the given string which should not include a
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.

=item $time = urxvt::NOW

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

=cut

package urxvt;

use strict;

our $term;
our @HOOKNAME;
our $LIBDIR;

BEGIN {
   urxvt->bootstrap;

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

my $verbosity = $ENV{URXVT_PERL_VERBOSITY} || 10;

sub verbose {
   my ($level, $msg) = @_;
   warn "$msg\n"; #d#
}

my @invoke_cb;

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

   my $cb = $invoke_cb[$htype];

   verbose 10, "$HOOKNAME[$htype] (" . (join ", ", $term, @_) . ")"
      if $verbosity >= 10;

   while (my ($k, $v) = each %$cb) {
      return 1 if $v->($term, @_);
   }

   0
}

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

   for my $hook (0.. $#HOOKNAME) {
      my $name = $HOOKNAME[$hook];

      my $ref = $pkg->can ("on_" . lc $name)
         or next;

      $invoke_cb[$hook]{$ref*1} = $ref;
      set_should_invoke $hook, 1;
   }
}

my $script_pkg = "script0000";
my %script_pkg;

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

   $script_pkg{$path} ||= do {
      my $pkg = $script_pkg++;
      verbose 3, "loading script '$path' into package '$pkg'";

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

      eval "package $pkg; use strict; use utf8;\n"
         . "#line 1 \"$path\"\n"
         . do { local $/; <$fh> }
         or die "$path: $@";

      register_package $pkg;

      $pkg
   };
}

sub load_scripts($) {
   my ($dir) = @_;

   verbose 3, "loading scripts from '$dir'";

   load_script $_
      for grep -f $_,
         <$dir/perl-ext/*>;
}

sub on_init {
   my ($term) = @_;

   my $libdir = $term->resource ("perl_lib");

   load_scripts $libdir
      if defined $libdir;
}

register_package __PACKAGE__;
load_scripts $LIBDIR;

=back

=head2 The C<urxvt::term> Class

=over 4

=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 a likely non-exhaustive list of resource names, not all of which
are supported in every build, please see the source to see the actual
list:

  answerbackstring backgroundPixmap backspace_key boldFont boldItalicFont
  borderLess color cursorBlink cursorUnderline cutchars delete_key
  display_name embed ext_bwidth fade font geometry hold iconName
  imFont imLocale inputMethod insecure int_bwidth intensityStyles
  italicFont jumpScroll lineSpace loginShell mapAlert menu meta8
  modifier mouseWheelScrollPage name pastableTabs path perl perl_eval
  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 selectstyle
  shade term_name title transparent transparent_all tripleclickwords
  utmpInhibit visualBell

=cut

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

=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,
and optionally set them to new values.

=item $success = $term->selection_grab ($eventtime)

Try to request the primary selection from the server (for example, as set
by the next method).

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

Return the current selection text and optionally replace it by C<$newtext>.

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

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

=cut

sub urxvt::term::scr_overlay {
   my ($self, $x, $y, $text) = @_;

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

   my $w = 0;
   for (map $self->strwidth ($_), @lines) {
      $w = $_ if $w < $_;
   }

   $self->scr_overlay_new ($x, $y, $w, scalar @lines);
   $self->scr_overlay_set (0, $_, $lines[$_]) for 0.. $#lines;
}

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

Create a new (empty) overlay at the given position with the given
width/height. A 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.

=item $term->scr_overlay_off

Switch the overlay off again.

=item $term->scr_overlay_set_char ($x, $y, $char, $rend = OVERLAY_RSTYLE)

Put a single character (specified numerically) at the given overlay
position.

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

Write a string at the given position into the overlay.

=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.

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

Convert the given locale-encoded octets into a perl string.

=item $term->tt_write ($octets)

Write the octets given in C<$data> to the tty (i.e. as program input). To
pass characters instead of octets, you should convetr you strings first to
the locale-specific encoding using C<< $term->locale_encode >>.

=back

=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:

   # create a digital clock display in upper right corner
   $term->{timer} = urxvt::timer
                    ->new
                    ->start (urxvt::NOW)
                    ->cb (sub {
                       my ($timer) = @_;
                       my $time = $timer->at;
                       $timer->start ($time + 1);
                       $self->scr_overlay (-1, 0, 
                          POSIX::strftime "%H:%M:%S", localtime $time);
                    });

=over 4

=item $timer = new urxvt::timer

Create a new timer object in stopped state.

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

Set the callback to be called when the timer triggers.

=item $tstamp = $timer->at

Return the time this watcher will fire next.

=item $timer = $timer->set ($tstamp)

Set the time the event is generated to $tstamp.

=item $timer = $timer->start

Start the timer.

=item $timer = $timer->start ($tstamp)

Set the event trigger time to C<$tstamp> and start the timer.

=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 $term->{socket})
                 ->events (1) # wait for read data
                 ->start
                 ->cb (sub {
                   my ($iow, $revents) = @_;
                   # $revents must be 1 here, no need to check
                   sysread $term->{socket}, my $buf, 8192
                      or end-of-file;
                 });


=over 4

=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 filedescriptor (not handle) to watch.

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

Set the event mask to watch. Bit #0 (value C<1>) enables watching for read
data, Bit #1 (value C<2>) enables watching for write data.

=item $iow = $iow->start

Start watching for requested events on the given handle.

=item $iow = $iow->stop

Stop watching for events on the given filehandle.

=back

=head1 ENVIRONMENT

=head2 URXVT_PERL_VERBOSITY

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

=over 4

=item 0 - only fatal messages

=item 3 - script loading and management

=item 10 - all events received

=back

=head1 AUTHOR

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

=cut

1
Revision:	1.6
Committed:	Mon Jan 2 18:20:23 2006 UTC (18 years, 4 months ago) by root
Branch:	MAIN
Changes since 1.5:	+71 -18 lines
Log Message:	* empty log message *
#	User	Rev	Content
1	root	1.1	=head1 NAME
2
3	root	1.3	rxvtperl - rxvt-unicode's embedded perl interpreter
4	root	1.1
5			=head1 SYNOPSIS
6
7	root	1.3	* Put your scripts into F<@@RXVT_LIBDIR@@/urxvt/perl-ext/>, they will be loaded automatically.
8	root	1.1
9	root	1.3	* Scripts are evaluated in a 'use strict' and 'use utf8' environment, and
10			thus must be encoded as UTF-8.
11	root	1.1
12			sub on_sel_grab {
13			warn "you selected ", $_[0]->selection;
14	root	1.3	()
15	root	1.1	}
16
17			1
18
19			=head1 DESCRIPTION
20
21	root	1.6	On startup, @@RXVT_NAME@@ will scan F<@@RXVT_LIBDIR@@/urxvt/perl-ext/>
22			for files and will load them. Everytime a terminal object gets created,
23			the directory specified by the C<perl-lib> resource will be additionally
24			scanned.
25
26			Each script will only ever be loaded once, even in @@RXVT_NAME@@d, where
27			scripts will be shared for all terminals.
28
29			Hooks in scripts specified by C<perl-lib> will only be called for the
30			terminals created with that specific option value.
31
32			=head2 General API Considerations
33
34			All objects (such as terminals, time watchers etc.) are typical
35			reference-to-hash objects. The hash can be used to store anything you
36			like. The only reserved member is C<_ptr>, which must not be changed.
37
38			When objects are destroyed on the C++ side, the perl object hashes are
39			emptied, so its best to store related objects such as time watchers and
40			the like inside the terminal object so they get destroyed as soon as the
41			terminal is destroyed.
42
43	root	1.1	=head2 Hooks
44
45			The following subroutines can be declared in loaded scripts, and will be called
46			whenever the relevant event happens.
47
48			All of them must return a boolean value. If it is true, then the event
49			counts as being I<consumed>, and the invocation of other hooks is skipped,
50			and the relevant action might not be carried out by the C++ code.
51
52			When in doubt, return a false value (preferably C<()>).
53
54			=over 4
55
56			=item on_init $term
57
58			Called after a new terminal object has been initialized, but before
59			windows are created or the command gets run.
60
61			=item on_reset $term
62
63			Called after the screen is "reset" for any reason, such as resizing or
64			control sequences. Here is where you can react on changes to size-related
65			variables.
66
67			=item on_start $term
68
69			Called at the very end of initialisation of a new terminal, just before
70			returning to the mainloop.
71
72			=item on_sel_make $term, $eventtime
73
74			Called whenever a selection has been made by the user, but before the
75			selection text is copied, so changes to the beginning, end or type of the
76			selection will be honored.
77
78			Returning a true value aborts selection making by urxvt, in which case you
79			have to make a selection yourself by calling C<< $term->selection_grab >>.
80
81			=item on_sel_grab $term, $eventtime
82
83			Called whenever a selection has been copied, but before the selection is
84			requested from the server. The selection text can be queried and changed
85			by calling C<< $term->selection >>.
86
87			Returning a true value aborts selection grabbing. It will still be hilighted.
88
89			=item on_focus_in $term
90
91			Called whenever the window gets the keyboard focus, before urxvt does
92			focus in processing.
93
94			=item on_focus_out $term
95
96			Called wheneever the window loses keyboard focus, before urxvt does focus
97			out processing.
98
99			=item on_view_change $term, $offset
100
101			Called whenever the view offset changes, i..e the user or program
102			scrolls. Offset C<0> means display the normal terminal, positive values
103			show this many lines of scrollback.
104
105			=item on_scroll_back $term, $lines, $saved
106
107			Called whenever lines scroll out of the terminal area into the scrollback
108			buffer. C<$lines> is the number of lines scrolled out and may be larger
109			than the scroll back buffer or the terminal.
110
111			It is called before lines are scrolled out (so rows 0 .. min ($lines - 1,
112			$nrow - 1) represent the lines to be scrolled out). C<$saved> is the total
113			number of lines that will be in the scrollback buffer.
114
115			=item on_tty_activity $term NYI
116
117			Called whenever the program(s) running in the urxvt window send output.
118
119			=item on_refresh_begin $term
120
121			Called just before the screen gets redrawn. Can be used for overlay
122			or similar effects by modify terminal contents in refresh_begin, and
123			restoring them in refresh_end. The built-in overlay and selection display
124			code is run after this hook, and takes precedence.
125
126			=item on_refresh_end $term
127
128			Called just after the screen gets redrawn. See C<on_refresh_begin>.
129
130			=back
131
132			=head2 Functions in the C<urxvt> Package
133
134			=over 4
135
136			=item urxvt::fatal $errormessage
137
138			Fatally aborts execution with the given error message. Avoid at all
139			costs! The only time this is acceptable is when the terminal process
140			starts up.
141
142			=item urxvt::warn $string
143
144	root	1.6	Calls C<rxvt_warn> with the given string which should not include a
145	root	1.1	newline. The module also overwrites the C<warn> builtin with a function
146			that calls this function.
147
148			Using this function has the advantage that its output ends up in the
149			correct place, e.g. on stderr of the connecting urxvtc client.
150
151			=item $time = urxvt::NOW
152
153			Returns the "current time" (as per the event loop).
154
155			=cut
156
157			package urxvt;
158
159			use strict;
160
161			our $term;
162			our @HOOKNAME;
163			our $LIBDIR;
164
165			BEGIN {
166			urxvt->bootstrap;
167
168			# overwrite perl's warn
169			*CORE::GLOBAL::warn = sub {
170			my $msg = join "", @_;
171			$msg .= "\n"
172			unless $msg =~ /\n$/;
173			urxvt::warn ($msg);
174			};
175			}
176
177			my $verbosity = $ENV{URXVT_PERL_VERBOSITY} \|\| 10;
178
179			sub verbose {
180			my ($level, $msg) = @_;
181			warn "$msg\n"; #d#
182			}
183
184			my @invoke_cb;
185
186			# called by the rxvt core
187			sub invoke {
188			local $term = shift;
189			my $htype = shift;
190
191			my $cb = $invoke_cb[$htype];
192
193			verbose 10, "$HOOKNAME[$htype] (" . (join ", ", $term, @_) . ")"
194			if $verbosity >= 10;
195
196			while (my ($k, $v) = each %$cb) {
197			return 1 if $v->($term, @_);
198			}
199
200			0
201			}
202
203			# find on_xxx subs in the package and register them
204			# as hooks
205			sub register_package($) {
206			my ($pkg) = @_;
207
208			for my $hook (0.. $#HOOKNAME) {
209			my $name = $HOOKNAME[$hook];
210
211			my $ref = $pkg->can ("on_" . lc $name)
212			or next;
213
214			$invoke_cb[$hook]{$ref*1} = $ref;
215			set_should_invoke $hook, 1;
216			}
217			}
218
219			my $script_pkg = "script0000";
220			my %script_pkg;
221
222			# load a single script into its own package, once only
223			sub load_script($) {
224			my ($path) = @_;
225
226			$script_pkg{$path} \|\|= do {
227			my $pkg = $script_pkg++;
228			verbose 3, "loading script '$path' into package '$pkg'";
229
230			open my $fh, "<:raw", $path
231			or die "$path: $!";
232
233			eval "package $pkg; use strict; use utf8;\n"
234			. "#line 1 \"$path\"\n"
235			. do { local $/; <$fh> }
236			or die "$path: $@";
237
238			register_package $pkg;
239
240			$pkg
241			};
242			}
243
244	root	1.6	sub load_scripts($) {
245			my ($dir) = @_;
246
247			verbose 3, "loading scripts from '$dir'";
248
249			load_script $_
250			for grep -f $_,
251			<$dir/perl-ext/*>;
252			}
253
254			sub on_init {
255			my ($term) = @_;
256
257			my $libdir = $term->resource ("perl_lib");
258
259			load_scripts $libdir
260			if defined $libdir;
261			}
262
263			register_package __PACKAGE__;
264			load_scripts $LIBDIR;
265	root	1.1
266			=back
267
268			=head2 The C<urxvt::term> Class
269
270			=over 4
271
272	root	1.4	=item $value = $term->resource ($name[, $newval])
273
274			Returns the current resource value associated with a given name and
275			optionally sets a new value. Setting values is most useful in the C<init>
276			hook. Unset resources are returned and accepted as C<undef>.
277
278			The new value must be properly encoded to a suitable character encoding
279			before passing it to this method. Similarly, the returned value may need
280			to be converted from the used encoding to text.
281
282			Resource names are as defined in F<src/rsinc.h>. Colours can be specified
283			as resource names of the form C<< color+<index> >>, e.g. C<color+5>. (will
284			likely change).
285
286			Please note that resource strings will currently only be freed when the
287			terminal is destroyed, so changing options frequently will eat memory.
288
289	root	1.5	Here is a a likely non-exhaustive list of resource names, not all of which
290			are supported in every build, please see the source to see the actual
291			list:
292
293			answerbackstring backgroundPixmap backspace_key boldFont boldItalicFont
294			borderLess color cursorBlink cursorUnderline cutchars delete_key
295			display_name embed ext_bwidth fade font geometry hold iconName
296			imFont imLocale inputMethod insecure int_bwidth intensityStyles
297			italicFont jumpScroll lineSpace loginShell mapAlert menu meta8
298	root	1.6	modifier mouseWheelScrollPage name pastableTabs path perl perl_eval
299			perl_lib pointerBlank pointerBlankDelay preeditType print_pipe pty_fd
300			reverseVideo saveLines scrollBar scrollBar_align scrollBar_floating
301			scrollBar_right scrollBar_thickness scrollTtyKeypress scrollTtyOutput
302			scrollWithBuffer scrollstyle secondaryScreen secondaryScroll selectstyle
303			shade term_name title transparent transparent_all tripleclickwords
304			utmpInhibit visualBell
305	root	1.5
306	root	1.4	=cut
307
308			sub urxvt::term::resource($$;$) {
309			my ($self, $name) = (shift, shift);
310			unshift @_, $self, $name, ($name =~ s/\s\+\s(\d+)$// ? $1 : 0);
311			goto &urxvt::term::_resource;
312			}
313
314	root	1.1	=item ($row, $col) = $term->selection_mark ([$row, $col])
315
316			=item ($row, $col) = $term->selection_beg ([$row, $col])
317
318			=item ($row, $col) = $term->selection_end ([$row, $col])
319
320			Return the current values of the selection mark, begin or end positions,
321			and optionally set them to new values.
322
323			=item $success = $term->selection_grab ($eventtime)
324
325			Try to request the primary selection from the server (for example, as set
326			by the next method).
327
328			=item $oldtext = $term->selection ([$newtext])
329
330			Return the current selection text and optionally replace it by C<$newtext>.
331
332			=item $term->scr_overlay ($x, $y, $text)
333
334			Create a simple multi-line overlay box. See the next method for details.
335
336			=cut
337
338			sub urxvt::term::scr_overlay {
339			my ($self, $x, $y, $text) = @_;
340
341			my @lines = split /\n/, $text;
342
343			my $w = 0;
344	root	1.6	for (map $self->strwidth ($_), @lines) {
345	root	1.1	$w = $_ if $w < $_;
346			}
347
348			$self->scr_overlay_new ($x, $y, $w, scalar @lines);
349			$self->scr_overlay_set (0, $_, $lines[$_]) for 0.. $#lines;
350			}
351
352			=item $term->scr_overlay_new ($x, $y, $width, $height)
353
354			Create a new (empty) overlay at the given position with the given
355			width/height. A border will be put around the box. If either C<$x> or
356			C<$y> is negative, then this is counted from the right/bottom side,
357			respectively.
358
359			=item $term->scr_overlay_off
360
361			Switch the overlay off again.
362
363			=item $term->scr_overlay_set_char ($x, $y, $char, $rend = OVERLAY_RSTYLE)
364
365			Put a single character (specified numerically) at the given overlay
366			position.
367
368			=item $term->scr_overlay_set ($x, $y, $text)
369
370			Write a string at the given position into the overlay.
371
372	root	1.6	=item $cellwidth = $term->strwidth $string
373
374			Returns the number of screen-cells this string would need. Correctly
375			accounts for wide and combining characters.
376
377			=item $octets = $term->locale_encode $string
378
379			Convert the given text string into the corresponding locale encoding.
380
381			=item $string = $term->locale_decode $octets
382
383			Convert the given locale-encoded octets into a perl string.
384
385			=item $term->tt_write ($octets)
386
387			Write the octets given in C<$data> to the tty (i.e. as program input). To
388			pass characters instead of octets, you should convetr you strings first to
389			the locale-specific encoding using C<< $term->locale_encode >>.
390
391	root	1.1	=back
392
393			=head2 The C<urxvt::timer> Class
394
395			This class implements timer watchers/events. Time is represented as a
396			fractional number of seconds since the epoch. Example:
397
398			# create a digital clock display in upper right corner
399			$term->{timer} = urxvt::timer
400			->new
401			->start (urxvt::NOW)
402			->cb (sub {
403			my ($timer) = @_;
404			my $time = $timer->at;
405			$timer->start ($time + 1);
406			$self->scr_overlay (-1, 0,
407			POSIX::strftime "%H:%M:%S", localtime $time);
408			});
409
410			=over 4
411
412			=item $timer = new urxvt::timer
413
414			Create a new timer object in stopped state.
415
416			=item $timer = $timer->cb (sub { my ($timer) = @_; ... })
417
418			Set the callback to be called when the timer triggers.
419
420			=item $tstamp = $timer->at
421
422			Return the time this watcher will fire next.
423
424			=item $timer = $timer->set ($tstamp)
425
426			Set the time the event is generated to $tstamp.
427
428			=item $timer = $timer->start
429
430			Start the timer.
431
432			=item $timer = $timer->start ($tstamp)
433
434			Set the event trigger time to C<$tstamp> and start the timer.
435
436			=item $timer = $timer->stop
437
438			Stop the timer.
439
440			=back
441
442			=head2 The C<urxvt::iow> Class
443
444			This class implements io watchers/events. Example:
445
446			$term->{socket} = ...
447			$term->{iow} = urxvt::iow
448			->new
449			->fd (fileno $term->{socket})
450			->events (1) # wait for read data
451			->start
452			->cb (sub {
453			my ($iow, $revents) = @_;
454			# $revents must be 1 here, no need to check
455			sysread $term->{socket}, my $buf, 8192
456			or end-of-file;
457			});
458
459
460			=over 4
461
462			=item $iow = new urxvt::iow
463
464			Create a new io watcher object in stopped state.
465
466			=item $iow = $iow->cb (sub { my ($iow, $reventmask) = @_; ... })
467
468			Set the callback to be called when io events are triggered. C<$reventmask>
469			is a bitset as described in the C<events> method.
470
471			=item $iow = $iow->fd ($fd)
472
473			Set the filedescriptor (not handle) to watch.
474
475			=item $iow = $iow->events ($eventmask)
476
477			Set the event mask to watch. Bit #0 (value C<1>) enables watching for read
478			data, Bit #1 (value C<2>) enables watching for write data.
479
480			=item $iow = $iow->start
481
482			Start watching for requested events on the given handle.
483
484			=item $iow = $iow->stop
485
486			Stop watching for events on the given filehandle.
487
488			=back
489
490	root	1.4	=head1 ENVIRONMENT
491
492			=head2 URXVT_PERL_VERBOSITY
493
494			This variable controls the verbosity level of the perl extension. Higher
495			numbers indicate more verbose output.
496
497			=over 4
498
499			=item 0 - only fatal messages
500
501			=item 3 - script loading and management
502
503			=item 10 - all events received
504
505			=back
506
507	root	1.1	=head1 AUTHOR
508
509			Marc Lehmann <pcg@goof.com>
510			http://software.schmorp.de/pkg/rxvt-unicode
511
512			=cut
513
514			1