Provided by: rxvt-unicode_9.22-6_amd64 bug

NAME

       urxvtperl - rxvt-unicode's embedded perl interpreter

SYNOPSIS

          # create a file grab_test in $HOME:

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

          # start a urxvt using it:

          urxvt --perl-lib $HOME -pe grab_test

DESCRIPTION

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

       Scripts are compiled in a 'use strict "vars"' 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.

PREPACKAGED EXTENSIONS

       A number of extensions are delivered with this release. You can find them in
       <libdir>/urxvt/perl/, and the documentation can be viewed using 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 "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 "."  replaced by "-"), in
       which case the corresponding extension is loaded automatically. For this to work the
       extension must define META comments for its resources.

API DOCUMENTATION

   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 "_ptr" or "_hook") are reserved for internal uses and 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:

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

       $string
           A perl text string, with an emphasis on 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.

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

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

   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 $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 "_": these are reserved for internal use.

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

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

   META comments
       Rxvt-unicode recognizes special meta comments in extensions that define different types of
       metadata.

       Currently, it recognises only one such comment:

       #:META:RESOURCE:name:type:desc
           The RESOURCE comment defines a resource used by the extension, where "name" is the
           resource name, "type" is the resource type, "boolean" or "string", and "desc" is the
           resource description.

   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
       "Extension Objects" section.

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

       When in doubt, return a false value (preferably "()").

       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
           "on_start" hook is a better place.

       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.

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

       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.

       on_child_start $term, $pid
           Called just after the child process has been "fork"ed.

       on_child_exit $term, $status
           Called just after the child process has exited. $status is the status from "waitpid".

       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 "$term->selection_grab".

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

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

       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 selection example extension.

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

       on_scroll_back $term, $lines, $saved
           Called whenever lines scroll out of the terminal area into the scrollback buffer.
           $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). $saved is the total number of lines that will
           be in the scrollback buffer.

       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.

           "on_osc_seq_perl" should be used for new behaviour.

       on_osc_seq_perl $term, $args, $resp
           Called whenever the ESC ] 777 ; 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 string should start with the extension name
           (sans -osc) and a semicolon, to distinguish it from commands for other extensions, and
           this might be enforced in the future.

           For example, "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, $resp contains the end-of-args separator used by the sender.

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

       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.

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

       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.

       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.

       on_refresh_end $term
           Called just after the screen gets redrawn. See "on_refresh_begin".

       on_action $term, $string
           Called whenever an action is invoked for the corresponding extension (e.g. via a
           "extension:string" builtin action bound to a key, see description of the 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.

       on_user_command $term, $string *DEPRECATED*
           Called whenever a user-configured event is being activated (e.g. via a "perl:string"
           action bound to a key, see description of the keysym resource in the urxvt(1)
           manpage).

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

       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.

       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.

       on_root_event $term, $event
           Like "on_x_event", but is called for events on the root window.

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

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

       on_configure_notify $term, $event
       on_property_notify $term, $event
       on_key_press $term, $event, $keysym, $octets
       on_key_release $term, $event, $keysym
       on_button_press $term, $event
       on_button_release $term, $event
       on_motion_notify $term, $event
       on_map_notify $term, $event
       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 "row" and "col", which are the (real, not screen-based) row and
           column under the mouse cursor.

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

       on_client_message $term, $event
       on_wm_protocols $term, $event
       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).

       on_bell $term
           Called on receipt of a bell character.

   Variables in the "urxvt" Package
       $urxvt::LIBDIR
           The rxvt-unicode library directory, where, among other things, the perl modules and
           scripts are stored.

       $urxvt::RESCLASS, $urxvt::RESCLASS
           The resource class and name rxvt-unicode uses to look up X resources.

       $urxvt::RXVTNAME
           The basename of the installed binaries, usually "urxvt".

       $urxvt::TERM
           The current terminal. This variable stores the current "urxvt::term" object, whenever
           a callback/hook is executing.

       @urxvt::TERM_INIT
           All code references in this array will be called as methods of the next newly created
           "urxvt::term" object (during the "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.

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

   Functions in the "urxvt" Package
       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.

       urxvt::warn $string
           Calls "rxvt_warn" with the given string which should include a trailing newline. The
           module also overwrites the "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.

       @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).

       $time = urxvt::NOW
           Returns the "current time" (as per the event loop).

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

   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.

       $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.

       $rend = urxvt::OVERLAY_RSTYLE
           Return the rendition mask used for overlays by default.

       $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.

       $foreground = urxvt::GET_BASEFG $rend
       $background = urxvt::GET_BASEBG $rend
           Return the foreground/background colour index, respectively.

       $rend = urxvt::SET_FGCOLOR $rend, $new_colour
       $rend = urxvt::SET_BGCOLOR $rend, $new_colour
       $rend = urxvt::SET_COLOR $rend, $new_fg, $new_bg
           Replace the foreground/background colour in the rendition mask with the specified one.

       $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.

       $rend = urxvt::SET_CUSTOM $rend, $new_value
           Change the custom value.

   The "urxvt::term::extension" class
       Each extension attached to a terminal object is represented by a "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.

       $urxvt_term = $self->{term}
           Returns the "urxvt::term" object associated with this instance of the extension. This
           member must not be changed in any way.

       $self->enable ($hook_name => $cb[, $hook_name => $cb..])
           Dynamically enable the given hooks (named without the "on_" prefix) for this
           extension, replacing any hook previously installed via "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 "on" method of the
           "urxvt::term" class.

       $self->disable ($hook_name[, $hook_name..])
           Dynamically disable the given hooks.

       $guard = $self->on ($hook_name => $cb[, $hook_name => $cb..])
           Similar to the "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.

       $self->bind_action ($hotkey, $action)
       $self->x_resource ($pattern)
       $self->x_resource_boolean ($pattern)
           These methods support an additional "%" prefix for $action or $pattern when called on
           an extension object, compared to the "urxvt::term" methods of the same name - see the
           description of these methods in the "urxvt::term" class for details.

   The "urxvt::anyevent" Class
       The sole purpose of this class is to deliver an interface to the "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.

   The "urxvt::term" Class
       $term = new urxvt::term $envhashref, $rxvtname, [arg...]
           Creates a new terminal, very similar as if you had started it with system "$rxvtname,
           arg...". $envhashref must be a reference to a %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 "undef" if the new instance didn't initialise perl, and the terminal
           object otherwise. The "init" and "start" hooks will be called before this call
           returns, and are free to refer to global data (which is race free).

       $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.

       $term->exec_async ($cmd[, @args])
           Works like the combination of the "fork"/"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. "PATH") and should be preferred over explicit calls
           to "exec" or "system".

           Returns the pid of the subprocess or "undef" on error.

       $isset = $term->option ($optval[, $set])
           Returns true if the option specified by $optval is enabled, and optionally change it.
           All option values are stored by name in the hash %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
           /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

       $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 "init" hook. Unset resources are
           returned and accepted as "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 src/rsinc.h. Colours can be specified as resource
           names of the form "color+<index>", e.g. "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 /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

       $value = $term->x_resource ($pattern)
           Returns the X-Resource for the given pattern, excluding the program or class name,
           i.e.  "$term->x_resource ("boldFont")" should return the same value as used by this
           instance of rxvt-unicode. Returns "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 "%." will be replaced by the name of the extension and a dot, and
           the lone string "%" 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 "on_start" hook, as there is only one
           resource database per display, and later invocations might return the wrong resources.

       $value = $term->x_resource_boolean ($pattern)
           Like "x_resource", above, but interprets the string value as a boolean and returns 1
           for true values, 0 for false values and "undef" if the resource or option isn't
           specified.

           You should always use this method to parse boolean resources.

       $action = $term->lookup_keysym ($keysym, $state)
           Returns the action bound to key combination "($keysym, $state)", if a binding for it
           exists, and "undef" otherwise.

       $success = $term->bind_action ($key, $action)
           Adds a key binding exactly as specified via a "keysym" resource. See the "keysym"
           resource in the urxvt(1) manpage.

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

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

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

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

       $rend = $term->rstyle ([$new_rstyle])
           Return and optionally change the current rendition. Text that is output by the
           terminal application will use this style.

       ($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).

       ($row, $col) = $term->selection_mark ([$row, $col])
       ($row, $col) = $term->selection_beg ([$row, $col])
       ($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 $row and $col, and
           the selection screen is set to the current screen.

       $screen = $term->selection_screen ([$screen])
           Returns the current selection screen, and then optionally sets it.

       $term->selection_make ($eventtime[, $rectangular])
           Tries to make a selection as set by "selection_beg" and "selection_end". If
           $rectangular is true (default: false), a rectangular selection will be made. This is
           the preferred function to make a selection.

       $success = $term->selection_grab ($eventtime[, $clipboard])
           Try to acquire ownership of the primary (clipboard if $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 "on_sel_grab"
           hooks.

       $oldtext = $term->selection ([$newtext, $clipboard])
           Return the current selection (clipboard if $clipboard is true) text and optionally
           replace it by $newtext.

       $term->selection_clear ([$clipboard])
           Revoke ownership of the primary (clipboard if $clipboard is true) selection.

       $term->overlay_simple ($x, $y, $text)
           Create a simple multi-line overlay box. See the next method for details.

       $term->overlay ($x, $y, $width, $height[, $rstyle[, $border]])
           Create a new (empty) overlay at the given position with the given width/height.
           $rstyle defines the initial rendition style (default: "OVERLAY_RSTYLE").

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

           If either $x or $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 "urxvt::overlay" objects are:

           $overlay->set ($x, $y, $text[, $rend])
               Similar to "$term->ROW_t" and "$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 $rend is missing, then the rendition will not be changed.

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

           $overlay->show
               If hidden, display the overlay again.

       $popup = $term->popup ($event)
           Creates a new "urxvt::popup" object that implements a popup menu. The $event must be
           the event causing the menu to pop up (a button event, currently).

       $cellwidth = $term->strwidth ($string)
           Returns the number of screen-cells this string would need. Correctly accounts for wide
           and combining characters.

       $octets = $term->locale_encode ($string)
           Convert the given text string into the corresponding locale encoding.

       $string = $term->locale_decode ($octets)
           Convert the given locale-encoded octets into a perl string.

       $term->scr_xor_span ($beg_row, $beg_col, $end_row, $end_col[, $rstyle])
           XORs the rendition values in the given span with the provided value (default:
           "RS_RVid"), which MUST NOT contain font styles. Useful in refresh hooks to provide
           effects similar to the selection.

       $term->scr_xor_rect ($beg_row, $beg_col, $end_row, $end_col[, $rstyle1[, $rstyle2]])
           Similar to "scr_xor_span", but xors a rectangle instead. Trailing whitespace will
           additionally be xored with the $rstyle2, which defaults to "RS_RVid | RS_Uline", which
           removes reverse video again and underlines it instead. Both styles MUST NOT contain
           font styles.

       $term->scr_bell
           Ring the bell!

       $term->scr_add_lines ($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
           "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 "on_add_lines" hook,
           though.

       $term->scr_change_screen ($screen)
           Switch to given screen - 0 primary, 1 secondary.

       $term->cmd_parse ($octets)
           Similar to "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.

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

       $term->tt_write_user_input ($octets)
           Like "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
           ("tt_write" doesn't do that).

           The typical use case would be inside "on_action" hooks.

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

       $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
           "urxvt::timer->events". Make sure to always restore the previous value.

       $fd = $term->pty_fd
           Returns the master file descriptor for the pty in use, or "-1" if no pty is used.

       $windowid = $term->parent
           Return the window id of the toplevel window.

       $windowid = $term->vt
           Return the window id of the terminal window.

       $term->vt_emask_add ($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);

       $term->set_urgency ($set)
           Enable/disable the urgency hint on the toplevel window.

       $term->focus_in
       $term->focus_out
       $term->key_press ($state, $keycode[, $time])
       $term->key_release ($state, $keycode[, $time])
           Deliver various fake events to to terminal.

       $window_width = $term->width ([$new_value])
       $window_height = $term->height ([$new_value])
       $font_width = $term->fwidth ([$new_value])
       $font_height = $term->fheight ([$new_value])
       $font_ascent = $term->fbase ([$new_value])
       $terminal_rows = $term->nrow ([$new_value])
       $terminal_columns = $term->ncol ([$new_value])
       $has_focus = $term->focus ([$new_value])
       $is_mapped = $term->mapped ([$new_value])
       $max_scrollback = $term->saveLines ([$new_value])
       $nrow_plus_saveLines = $term->total_rows ([$new_value])
       $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.

       $x_display = $term->display_id
           Return the DISPLAY used by rxvt-unicode.

       $lc_ctype = $term->locale
           Returns the LC_CTYPE category string used by this rxvt-unicode.

       $env = $term->env
           Returns a copy of the environment in effect for the terminal as a hashref similar to
           "\%ENV".

       @envv = $term->envv
           Returns the environment as array of strings of the form "VAR=VALUE".

       @argv = $term->argv
           Return the argument vector as this terminal, similar to @ARGV, but includes the
           program name as first element.

       $modifiermask = $term->ModLevel3Mask
       $modifiermask = $term->ModMetaMask
       $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.

       $screen = $term->current_screen
           Returns the currently displayed screen (0 primary, 1 secondary).

       $cursor_is_hidden = $term->hidden_cursor
           Returns whether the cursor is currently hidden or not.

       $view_start = $term->view_start ([$newvalue])
           Returns the row number of the topmost displayed line. Maximum value is 0, which
           displays the normal terminal contents. Lower values scroll this many lines into the
           scrollback buffer.

       $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.

       $term->refresh_check
           Checks if a refresh has been requested and, if so, schedules one.

       $text = $term->ROW_t ($row_number[, $new_text[, $start_col]])
           Returns the text of the entire row with number $row_number. Row "$term->top_row" is
           the topmost terminal line, row "$term->nrow-1" is the bottommost terminal line.
           Nothing will be returned if a nonexistent line is requested.

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

           $text is in a special encoding: tabs and wide characters that use more than one cell
           when displayed are padded with $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 "substr" and
           similar functions work on screen cells and not on characters.

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

       $rend = $term->ROW_r ($row_number[, $new_rend[, $start_col]])
           Like "$term->ROW_t", but returns an arrayref with rendition bitsets. Rendition bitsets
           contain information about colour, font, font styles and similar information. See also
           "$term->ROW_t".

           When setting rendition, the font mask will be ignored.

           See the section on RENDITION, above.

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

       $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)).

       $line = $term->line ($row_number)
           Create and return a new "urxvt::line" object that stores information about the logical
           line that row $row_number is part of. It supports the following methods:

           $text = $line->t ([$new_text])
               Returns or replaces the full text of the line, similar to "ROW_t"

           $rend = $line->r ([$new_rend])
               Returns or replaces the full rendition array of the line, similar to "ROW_r"

           $length = $line->l
               Returns the length of the line in cells, similar to "ROW_l".

           $rownum = $line->beg
           $rownum = $line->end
               Return the row number of the first/last row of the line, respectively.

           $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.

           ($row, $col) = $line->coord_of ($offset)
               Translates a string offset into terminal coordinates again.

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

       $string = $term->special_decode $text
           Converts rxvt-unicodes text representation into a perl string. See "$term->ROW_t" for
           details.

       $success = $term->grab_button ($button, $modifiermask[, $window = $term->vt])
       $term->ungrab_button ($button, $modifiermask[, $window = $term->vt])
           Register/unregister a synchronous button grab. See the XGrabButton manpage.

       $success = $term->grab ($eventtime[, $sync])
           Calls XGrabPointer and XGrabKeyboard in asynchronous (default) or synchronous ($sync
           is true). Also remembers the grab timestamp.

       $term->allow_events_async
           Calls XAllowEvents with AsyncBoth for the most recent grab.

       $term->allow_events_sync
           Calls XAllowEvents with SyncBoth for the most recent grab.

       $term->allow_events_replay
           Calls XAllowEvents with both ReplayPointer and ReplayKeyboard for the most recent
           grab.

       $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.

       $atom = $term->XInternAtom ($atom_name[, $only_if_exists])
       $atom_name = $term->XGetAtomName ($atom)
       @atoms = $term->XListProperties ($window)
       ($type,$format,$octets) = $term->XGetWindowProperty ($window, $property)
       $term->XChangeProperty ($window, $property, $type, $format, $octets)
       $term->XDeleteProperty ($window, $property)
       $window = $term->DefaultRootWindow
       $term->XReparentWindow ($window, $parent, [$x, $y])
       $term->XMapWindow ($window)
       $term->XUnmapWindow ($window)
       $term->XMoveResizeWindow ($window, $x, $y, $width, $height)
       ($x, $y, $child_window) = $term->XTranslateCoordinates ($src, $dst, $x, $y)
       $term->XChangeInput ($window, $add_events[, $del_events])
       $keysym = $term->XStringToKeysym ($string)
       $string = $term->XKeysymToString ($keysym)
           Various X or X-related functions. The $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.

   The "urxvt::popup" Class
       $popup->add_title ($title)
           Adds a non-clickable title to the popup.

       $popup->add_separator ([$sepchr])
           Creates a separator, optionally using the character given as $sepchr.

       $popup->add_button ($text, $cb)
           Adds a clickable button to the popup. $cb is called whenever it is selected.

       $popup->add_toggle ($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.

       $popup->show
           Displays the popup (which is initially hidden).

   The "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]);
                           });

       $timer = new urxvt::timer
           Create a new timer object in started state. It is scheduled to fire immediately.

       $timer = $timer->cb (sub { my ($timer) = @_; ... })
           Set the callback to be called when the timer triggers.

       $timer = $timer->set ($tstamp[, $interval])
           Set the time the event is generated to $tstamp (and optionally specifies a new
           $interval).

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

       $timer = $timer->start
           Start the timer.

       $timer = $timer->start ($tstamp[, $interval])
           Set the event trigger time to $tstamp and start the timer. Optionally also replaces
           the interval.

       $timer = $timer->after ($delay[, $interval])
           Like "start", but sets the expiry timer to c<urxvt::NOW + $delay>.

       $timer = $timer->stop
           Stop the timer.

   The "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;
                        });

       $iow = new urxvt::iow
           Create a new io watcher object in stopped state.

       $iow = $iow->cb (sub { my ($iow, $reventmask) = @_; ... })
           Set the callback to be called when io events are triggered. $reventmask is a bitset as
           described in the "events" method.

       $iow = $iow->fd ($fd)
           Set the file descriptor (not handle) to watch.

       $iow = $iow->events ($eventmask)
           Set the event mask to watch. The only allowed values are "urxvt::EV_READ" and
           "urxvt::EV_WRITE", which might be ORed together, or "urxvt::EV_NONE".

       $iow = $iow->start
           Start watching for requested events on the given handle.

       $iow = $iow->stop
           Stop watching for events on the given file handle.

   The "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.

       $iw = new urxvt::iw
           Create a new idle watcher object in stopped state.

       $iw = $iw->cb (sub { my ($iw) = @_; ... })
           Set the callback to be called when the watcher triggers.

       $timer = $timer->start
           Start the watcher.

       $timer = $timer->stop
           Stop the watcher.

   The "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) = @_;
                              ...
                           });

       $pw = new urxvt::pw
           Create a new process watcher in stopped state.

       $pw = $pw->cb (sub { my ($pw, $exit_status) = @_; ... })
           Set the callback to be called when the timer triggers.

       $pw = $timer->start ($pid)
           Tells the watcher to start watching for process $pid.

       $pw = $pw->stop
           Stop the watcher.

ENVIRONMENT

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

       == 0 - fatal messages
       >= 3 - script loading and management
       >=10 - all called hooks
       >=11 - hook return values

AUTHOR

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