Provided by: rxvt-unicode_9.14-1_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' 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

       This section describes the extensions delivered with this release. You can find them in
       /usr/lib/urxvt/perl/.

       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

       selection (enabled by default)
           (More) intelligent selection. This extension tries to be more intelligent when the
           user extends selections (double-click and further clicks). Right now, it tries to
           select words, urls and complete shell-quoted arguments, which is very convenient, too,
           if your ls supports "--quoting-style=shell".

           A double-click usually selects the word under the cursor, further clicks will enlarge
           the selection.

           The selection works by trying to match a number of regexes and displaying them in
           increasing order of length. You can add your own regexes by specifying resources of
           the form:

              URxvt.selection.pattern-0: perl-regex
              URxvt.selection.pattern-1: perl-regex
              ...

           The index number (0, 1...) must not have any holes, and each regex must contain at
           least one pair of capturing parentheses, which will be used for the match. For
           example, the following adds a regex that matches everything between two vertical bars:

              URxvt.selection.pattern-0: \\|([^|]+)\\|

           Another example: Programs I use often output "absolute path: " at the beginning of a
           line when they process multiple files. The following pattern matches the filename
           (note, there is a single space at the very end):

              URxvt.selection.pattern-0: ^(/[^:]+):\

           You can look at the source of the selection extension to see more interesting uses,
           such as parsing a line from beginning to end.

           This extension also offers following bindable keyboard commands:

           rot13
               Rot-13 the selection when activated. Used via keyboard trigger:

                  URxvt.keysym.C-M-r: perl:selection:rot13

       option-popup (enabled by default)
           Binds a popup menu to Ctrl-Button2 that lets you toggle (some) options at runtime.

           Other extensions can extend this popup menu by pushing a code reference onto "@{
           $term-"{option_popup_hook} }>, which gets called whenever the popup is being
           displayed.

           Its sole argument is the popup menu, which can be modified.  It should either return
           nothing or a string, the initial boolean value and a code reference. The string will
           be used as button text and the code reference will be called when the toggle changes,
           with the new boolean value as first argument.

           The following will add an entry "myoption" that changes "$self->{myoption}":

              push @{ $self->{term}{option_popup_hook} }, sub {
                 ("my option" => $myoption, sub { $self->{myoption} = $_[0] })
              };

       selection-popup (enabled by default)
           Binds a popup menu to Ctrl-Button3 that lets you convert the selection text into
           various other formats/action (such as uri unescaping, perl evaluation, web-browser
           starting etc.), depending on content.

           Other extensions can extend this popup menu by pushing a code reference onto "@{
           $term-"{selection_popup_hook} }>, which gets called whenever the popup is being
           displayed.

           Its sole argument is the popup menu, which can be modified. The selection is in $_,
           which can be used to decide whether to add something or not.  It should either return
           nothing or a string and a code reference. The string will be used as button text and
           the code reference will be called when the button gets activated and should transform
           $_.

           The following will add an entry "a to b" that transforms all "a"s in the selection to
           "b"s, but only if the selection currently contains any "a"s:

              push @{ $self->{term}{selection_popup_hook} }, sub {
                 /a/ ? ("a to b" => sub { s/a/b/g }
                     : ()
              };

       searchable-scrollback<hotkey> (enabled by default)
           Adds regex search functionality to the scrollback buffer, triggered by a hotkey
           (default: "M-s"). While in search mode, normal terminal input/output is suspended and
           a regex is displayed at the bottom of the screen.

           Inputting characters appends them to the regex and continues incremental search.
           "BackSpace" removes a character from the regex, "Up" and "Down" search
           upwards/downwards in the scrollback buffer, "End" jumps to the bottom. "Escape" leaves
           search mode and returns to the point where search was started, while "Enter" or
           "Return" stay at the current position and additionally stores the first match in the
           current line into the primary selection if the "Shift" modifier is active.

           The regex defaults to "(?i)", resulting in a case-insensitive search. To get a case-
           sensitive search you can delete this prefix using "BackSpace" or simply use an
           uppercase character which removes the "(?i)" prefix.

           See perlre for more info about perl regular expression syntax.

       readline (enabled by default)
           A support package that tries to make editing with readline easier. At the moment, it
           reacts to clicking shift-left mouse button by trying to move the text cursor to this
           position. It does so by generating as many cursor-left or cursor-right keypresses as
           required (this only works for programs that correctly support wide characters).

           To avoid too many false positives, this is only done when:

           - the tty is in ICANON state.
           - the text cursor is visible.
           - the primary screen is currently being displayed.
           - the mouse is on the same (multi-row-) line as the text cursor.

           The normal selection mechanism isn't disabled, so quick successive clicks might
           interfere with selection creation in harmless ways.

       selection-autotransform
           This selection allows you to do automatic transforms on a selection whenever a
           selection is made.

           It works by specifying perl snippets (most useful is a single "s///" operator) that
           modify $_ as resources:

              URxvt.selection-autotransform.0: transform
              URxvt.selection-autotransform.1: transform
              ...

           For example, the following will transform selections of the form "filename:number",
           often seen in compiler messages, into "vi +$filename $word":

              URxvt.selection-autotransform.0: s/^([^:[:space:]]+):(\\d+):?$/vi +$2 \\Q$1\\E\\x0d/

           And this example matches the same,but replaces it with vi-commands you can paste
           directly into your (vi :) editor:

              URxvt.selection-autotransform.0: s/^([^:[:space:]]+(\\d+):?$/:e \\Q$1\\E\\x0d:$2\\x0d/

           Of course, this can be modified to suit your needs and your editor :)

           To expand the example above to typical perl error messages ("XXX at FILENAME line
           YYY."), you need a slightly more elaborate solution:

              URxvt.selection.pattern-0: ( at .*? line \\d+[,.])
              URxvt.selection-autotransform.0: s/^ at (.*?) line (\\d+)[,.]$/:e \\Q$1\E\\x0d:$2\\x0d/

           The first line tells the selection code to treat the unchanging part of every error
           message as a selection pattern, and the second line transforms the message into vi
           commands to load the file.

       tabbed
           This transforms the terminal into a tabbar with additional terminals, that is, it
           implements what is commonly referred to as "tabbed terminal". The topmost line
           displays a "[NEW]" button, which, when clicked, will add a new tab, followed by one
           button per tab.

           Clicking a button will activate that tab. Pressing Shift-Left and Shift-Right will
           switch to the tab left or right of the current one, while Shift-Down creates a new
           tab.

           The tabbar itself can be configured similarly to a normal terminal, but with a
           resource class of "URxvt.tabbed". In addition, it supports the following four
           resources (shown with defaults):

              URxvt.tabbed.tabbar-fg: <colour-index, default 3>
              URxvt.tabbed.tabbar-bg: <colour-index, default 0>
              URxvt.tabbed.tab-fg:    <colour-index, default 0>
              URxvt.tabbed.tab-bg:    <colour-index, default 1>

           See COLOR AND GRAPHICS in the urxvt(1) manpage for valid indices.

       matcher
           Uses per-line display filtering ("on_line_update") to underline text matching a
           certain pattern and make it clickable. When clicked with the mouse button specified in
           the "matcher.button" resource (default 2, or middle), the program specified in the
           "matcher.launcher" resource (default, the "urlLauncher" resource, "sensible-browser")
           will be started with the matched text as first argument.  The default configuration is
           suitable for matching URLs and launching a web browser, like the former "mark-urls"
           extension.

           The default pattern to match URLs can be overridden with the "matcher.pattern.0"
           resource, and additional patterns can be specified with numbered patterns, in a manner
           similar to the "selection" extension.  The launcher can also be overridden on a per-
           pattern basis.

           It is possible to activate the most recently seen match or a list of matches from the
           keyboard.  Simply bind a keysym to "perl:matcher:last" or "perl:matcher:list" as seen
           in the example below.

           Example configuration:

               URxvt.perl-ext:           default,matcher
               URxvt.urlLauncher:        sensible-browser
               URxvt.keysym.C-Delete:    perl:matcher:last
               URxvt.keysym.M-Delete:    perl:matcher:list
               URxvt.matcher.button:     1
               URxvt.matcher.pattern.1:  \\bwww\\.[\\w-]+\\.[\\w./?&@#-]*[\\w/-]
               URxvt.matcher.pattern.2:  \\B(/\\S+?):(\\d+)(?=:|$)
               URxvt.matcher.launcher.2: gvim +$2 $1

       xim-onthespot
           This (experimental) perl extension implements OnTheSpot editing. It does not work
           perfectly, and some input methods don't seem to work well with OnTheSpot editing in
           general, but it seems to work at least for SCIM and kinput2.

           You enable it by specifying this extension and a preedit style of "OnTheSpot", i.e.:

              urxvt -pt OnTheSpot -pe xim-onthespot

       kuake<hotkey>
           A very primitive quake-console-like extension. It was inspired by a description of how
           the programs "kuake" and "yakuake" work: Whenever the user presses a global
           accelerator key (by default "F10"), the terminal will show or hide itself. Another
           press of the accelerator key will hide or show it again.

           Initially, the window will not be shown when using this extension.

           This is useful if you need a single terminal that is not using any desktop space most
           of the time but is quickly available at the press of a key.

           The accelerator key is grabbed regardless of any modifiers, so this extension will
           actually grab a physical key just for this function.

           If you want a quake-like animation, tell your window manager to do so (fvwm can do
           it).

       overlay-osc
           This extension implements some OSC commands to display timed popups on the screen -
           useful for status displays from within scripts. You have to read the sources for more
           info.

       block-graphics-to-ascii
           A not very useful example of filtering all text output to the terminal by replacing
           all line-drawing characters (U+2500 .. U+259F) by a similar-looking ascii character.

       digital-clock
           Displays a digital clock using the built-in overlay.

       remote-clipboard
           Somewhat of a misnomer, this extension adds two menu entries to the selection popup
           that allows one to run external commands to store the selection somewhere and fetch it
           again.

           We use it to implement a "distributed selection mechanism", which just means that one
           command uploads the file to a remote server, and another reads it.

           The commands can be set using the "URxvt.remote-selection.store" and
           "URxvt.remote-selection.fetch" resources. The first should read the selection to store
           from STDIN (always in UTF-8), the second should provide the selection data on STDOUT
           (also in UTF-8).

           The defaults (which are likely useless to you) use rsh and cat:

              URxvt.remote-selection.store: rsh ruth 'cat >/tmp/distributed-selection'
              URxvt.remote-selection.fetch: rsh ruth 'cat /tmp/distributed-selection'

       selection-pastebin
           This is a little rarely useful extension that uploads the selection as textfile to a
           remote site (or does other things). (The implementation is not currently secure for
           use in a multiuser environment as it writes to /tmp directly.).

           It listens to the "selection-pastebin:remote-pastebin" keyboard command, i.e.

              URxvt.keysym.C-M-e: perl:selection-pastebin:remote-pastebin

           Pressing this combination runs a command with "%" replaced by the name of the
           textfile. This command can be set via a resource:

              URxvt.selection-pastebin.cmd: rsync -apP % ruth:/var/www/www.ta-sa.org/files/txt/.

           And the default is likely not useful to anybody but the few people around here :)

           The name of the textfile is the hex encoded md5 sum of the selection, so the same
           content should lead to the same filename.

           After a successful upload the selection will be replaced by the text given in the
           "selection-pastebin-url" resource (again, the % is the placeholder for the filename):

              URxvt.selection-pastebin.url: http://www.ta-sa.org/files/txt/%

           Note to xrdb users: xrdb uses the C preprocessor, which might interpret the double "/"
           characters as comment start. Use "\057\057" instead, which works regardless of whether
           xrdb is used to parse the resource file or not.

       macosx-clipboard and macosx-clipboard-native
           These two modules implement an extended clipboard for Mac OS X. They are used like
           this:

              URxvt.perl-ext-common: default,macosx-clipboard
              URxvt.keysym.M-c: perl:macosx-clipboard:copy
              URxvt.keysym.M-v: perl:macosx-clipboard:paste

           The difference between them is that the native variant requires a perl from apple's
           devkit or so, and "macosx-clipboard" requires the "Mac::Pasteboard" module, works with
           other perls, has fewer bugs, is simpler etc. etc.

       example-refresh-hooks
           Displays a very simple digital clock in the upper right corner of the window.
           Illustrates overwriting the refresh callbacks to create your own overlays or changes.

       confirm-paste
           Displays a confirmation dialog when a paste containing at least a full line is
           detected.

       bell-command
           Runs the command specified by the "URxvt.bell-command" resource when a bell event
           occurs. For example, the following pops up a notification bubble with the text "Beep,
           Beep" using notify-send:

              URxvt.bell-command: notify-send "Beep, Beep"

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.

       It has the following methods and data members:

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

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

   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_user_command $term, $string
           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 assumed to change slightly in
           the future.

       on_register_command $term, $keysym, $modifiermask, $string
           Called after parsing a keysym resource but before registering the associated binding.
           If this hook returns TRUE the binding is not registered. It can be used to modify a
           binding by calling "register_command".

       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 TRUE, 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.

           subwindow.

       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::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. What 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 blendtype 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.

           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.

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

       $term->register_command ($keysym, $modifiermask, $string)
           Adds a key binding. This is a lower level api compared to "parse_keysym", as it
           expects a parsed key description, and can be used only inside either the "on_init"
           hook, to add a binding, or the "on_register_command" hook, to modify a parsed binding.

       $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), 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 $octets to the tty (i.e. as program input). To pass
           characters instead of octets, you should convert your strings first to the locale-
           specific encoding using "$term->locale_encode".

       $term->tt_paste ($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
       $window_height = $term->height
       $font_width = $term->fwidth
       $font_height = $term->fheight
       $font_ascent = $term->fbase
       $terminal_rows = $term->nrow
       $terminal_columns = $term->ncol
       $has_focus = $term->focus
       $is_mapped = $term->mapped
       $max_scrollback = $term->saveLines
       $nrow_plus_saveLines = $term->total_rows
       $topmost_scrollback_row = $term->top_row
           Return various integers describing terminal characteristics.

       $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.

       $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