RXVT-UNICODE/URXVT FREQUENTLY ASKED QUESTIONS Meta, Features & Commandline Issues My question isn't answered here, can I ask a human? Before sending me mail, you could go to IRC: "irc.freenode.net", channel "#rxvt-unicode" has some rxvt-unicode enthusiasts that might be interested in learning about new and exciting problems (but not FAQs :).

I use Gentoo, and I have a problem... There are three big problems with Gentoo Linux: first of all, most if not all Gentoo systems are completely broken (missing or mismatched header files, broken compiler etc. are just the tip of the iceberg); secondly, the Gentoo maintainer thinks it is a good idea to add broken patches to the code; and lastly, it should be called Gentoo GNU/Linux.

For these reasons, it is impossible to support rxvt-unicode on Gentoo.
Problems appearing on Gentoo systems will usually simply be ignored
unless they can be reproduced on non-Gentoo systems.

Does it support tabs, can I have a tabbed rxvt-unicode? Beginning with version 7.3, there is a perl extension that implements a simple tabbed terminal. It is installed by default, so any of these should give you tabs:

   urxvt -pe tabbed

   URxvt.perl-ext-common: default,tabbed

It will also work fine with tabbing functionality of many window
managers or similar tabbing programs, and its embedding-features allow
it to be embedded into other programs, as witnessed by doc/rxvt-tabbed
or the upcoming "Gtk2::URxvt" perl module, which features a tabbed urxvt
(murxvt) terminal as an example embedding application.

How do I know which rxvt-unicode version I'm using? The version number is displayed with the usage (-h). Also the escape sequence "ESC [ 8 n" sets the window title to the version number. When using the urxvtc client, the version displayed is that of the daemon.

Rxvt-unicode uses gobs of memory, how can I reduce that? Rxvt-unicode tries to obey the rule of not charging you for something you don't use. One thing you should try is to configure out all settings that you don't need, for example, Xft support is a resource hog by design, when used. Compiling it out ensures that no Xft font will be loaded accidentally when rxvt-unicode tries to find a font for your characters.

Also, many people (me included) like large windows and even larger
scrollback buffers: Without "--enable-unicode3", rxvt-unicode will use 6
bytes per screen cell. For a 160x?? window this amounts to almost a
kilobyte per line. A scrollback buffer of 10000 lines will then (if
full) use 10 Megabytes of memory. With "--enable-unicode3" it gets
worse, as rxvt-unicode then uses 8 bytes per screen cell.

How can I start urxvtd in a race-free way? Try "urxvtd -f -o", which tells urxvtd to open the display, create the listening socket and then fork.

How can I start urxvtd automatically when I run urxvtc? If you want to start urxvtd automatically whenever you run urxvtc and the daemon isn't running yet, use this script:

   #!/bin/sh
   urxvtc "$@"
   if [ $? -eq 2 ]; then
      urxvtd -q -o -f
      urxvtc "$@"
   fi

This tries to create a new terminal, and if fails with exit status 2,
meaning it couldn't connect to the daemon, it will start the daemon and
re-run the command. Subsequent invocations of the script will re-use the
existing daemon.

How do I distinguish whether I'm running rxvt-unicode or a regular xterm? I need this to decide about setting colors etc. The original rxvt and rxvt-unicode always export the variable "COLORTERM", so you can check and see if that is set. Note that several programs, JED, slrn, Midnight Commander automatically check this variable to decide whether or not to use color.

How do I set the correct, full IP address for the DISPLAY variable? If you've compiled rxvt-unicode with DISPLAY_IS_IP and have enabled insecure mode then it is possible to use the following shell script snippets to correctly set the display. If your version of rxvt-unicode wasn't also compiled with ESCZ_ANSWER (as assumed in these snippets) then the COLORTERM variable can be used to distinguish rxvt-unicode from a regular xterm.

Courtesy of Chuck Blake <[email protected]> with the following shell script
snippets:

   # Bourne/Korn/POSIX family of shells:
   [ ${TERM:-foo} = foo ] && TERM=xterm # assume an xterm if we don't know
   if [ ${TERM:-foo} = xterm ]; then
      stty -icanon -echo min 0 time 15 # see if enhanced rxvt or not
      echo -n '^[Z'
      read term_id
      stty icanon echo
      if [ ""${term_id} = '^[[?1;2C' -a ${DISPLAY:-foo} = foo ]; then
         echo -n '^[[7n'        # query the rxvt we are in for the DISPLAY string
         read DISPLAY           # set it in our local shell
      fi
   fi

How do I compile the manual pages on my own? You need to have a recent version of perl installed as /usr/bin/perl, one that comes with pod2man, pod2text and pod2xhtml (from Pod::Xhtml). Then go to the doc subdirectory and enter "make alldoc".

Isn't rxvt-unicode supposed to be small? Don't all those features bloat? I often get asked about this, and I think, no, they didn't cause extra bloat. If you compare a minimal rxvt and a minimal urxvt, you can see that the urxvt binary is larger (due to some encoding tables always being compiled in), but it actually uses less memory (RSS) after startup. Even with "--disable-everything", this comparison is a bit unfair, as many features unique to urxvt (locale, encoding conversion, iso14755 etc.) are already in use in this mode.

    text    data     bss     drs     rss filename
   98398    1664      24   15695    1824 rxvt --disable-everything
  188985    9048   66616   18222    1788 urxvt --disable-everything

When you "--enable-everything" (which *is* unfair, as this involves xft
and full locale/XIM support which are quite bloaty inside libX11 and my
libc), the two diverge, but not unreasonably so.

    text    data     bss     drs     rss filename
  163431    2152      24   20123    2060 rxvt --enable-everything
 1035683   49680   66648   29096    3680 urxvt --enable-everything

The very large size of the text section is explained by the east-asian
encoding tables, which, if unused, take up disk space but nothing else
and can be compiled out unless you rely on X11 core fonts that use those
encodings. The BSS size comes from the 64k emergency buffer that my c++
compiler allocates (but of course doesn't use unless you are out of
memory). Also, using an xft font instead of a core font immediately adds
a few megabytes of RSS. Xft indeed is responsible for a lot of RSS even
when not used.

Of course, due to every character using two or four bytes instead of
one, a large scrollback buffer will ultimately make rxvt-unicode use
more memory.

Compared to e.g. Eterm (5112k), aterm (3132k) and xterm (4680k), this
still fares rather well. And compared to some monsters like
gnome-terminal (21152k + extra 4204k in separate processes) or konsole
(22200k + extra 43180k in daemons that stay around after exit, plus half
a minute of startup time, including the hundreds of warnings it spits
out), it fares extremely well *g*.

Why C++, isn't that unportable/bloated/uncool? Is this a question? :) It comes up very often. The simple answer is: I had to write it, and C++ allowed me to write and maintain it in a fraction of the time and effort (which is a scarce resource for me). Put even shorter: It simply wouldn't exist without C++.

My personal stance on this is that C++ is less portable than C, but in
the case of rxvt-unicode this hardly matters, as its portability limits
are defined by things like X11, pseudo terminals, locale support and
unix domain sockets, which are all less portable than C++ itself.

Regarding the bloat, see the above question: It's easy to write programs
in C that use gobs of memory, an certainly possible to write programs in
C++ that don't. C++ also often comes with large libraries, but this is
not necessarily the case with GCC. Here is what rxvt links against on my
system with a minimal config:

   libX11.so.6 => /usr/X11R6/lib/libX11.so.6 (0x00002aaaaabc3000)
   libc.so.6 => /lib/libc.so.6 (0x00002aaaaadde000)
   libdl.so.2 => /lib/libdl.so.2 (0x00002aaaab01d000)
   /lib64/ld-linux-x86-64.so.2 (0x00002aaaaaaab000)

And here is rxvt-unicode:

   libX11.so.6 => /usr/X11R6/lib/libX11.so.6 (0x00002aaaaabc3000)
   libgcc_s.so.1 => /lib/libgcc_s.so.1 (0x00002aaaaada2000)
   libc.so.6 => /lib/libc.so.6 (0x00002aaaaaeb0000)
   libdl.so.2 => /lib/libdl.so.2 (0x00002aaaab0ee000)
   /lib64/ld-linux-x86-64.so.2 (0x00002aaaaaaab000)

No large bloated libraries (of course, none were linked in statically),
except maybe libX11 :)

Rendering, Font & Look and Feel Issues I can't get transparency working, what am I doing wrong? First of all, please address all transparency related issues to Sasha Vasko at [email protected] and do not bug the author about it. Also, if you can't get it working consider it a rite of passage: ... and you failed.

Here are four ways to get transparency. Do read the manpage and option
descriptions for the programs mentioned and rxvt-unicode. Really, do it!

1. Use transparent mode:

   Esetroot wallpaper.jpg
   urxvt -tr -tint red -sh 40

That works. If you think it doesn't, you lack transparency and tinting
support, or you are unable to read.

2. Use a simple pixmap and emulate pseudo-transparency. This enables you
to use effects other than tinting and shading: Just shade/tint/whatever
your picture with gimp or any other tool:

   convert wallpaper.jpg -blur 20x20 -modulate 30 background.jpg
   urxvt -pixmap "background.jpg;:root"

That works. If you think it doesn't, you lack AfterImage support, or you
are unable to read.

3. Use an ARGB visual:

   urxvt -depth 32 -fg grey90 -bg rgba:0000/0000/4444/cccc

This requires XFT support, and the support of your X-server. If that
doesn't work for you, blame Xorg and Keith Packard. ARGB visuals aren't
there yet, no matter what they claim. Rxvt-Unicode contains the
necessary bugfixes and workarounds for Xft and Xlib to make it work, but
that doesn't mean that your WM has the required kludges in place.

4. Use xcompmgr and let it do the job:

  xprop -frame -f _NET_WM_WINDOW_OPACITY 32c 
        -set _NET_WM_WINDOW_OPACITY 0xc0000000

Then click on a window you want to make transparent. Replace 0xc0000000
by other values to change the degree of opacity. If it doesn't work and
your server crashes, you got to keep the pieces.

Why does rxvt-unicode sometimes leave pixel droppings? Most fonts were not designed for terminal use, which means that character size varies a lot. A font that is otherwise fine for terminal use might contain some characters that are simply too wide. Rxvt-unicode will avoid these characters. For characters that are just "a bit" too wide a special "careful" rendering mode is used that redraws adjacent characters.

All of this requires that fonts do not lie about character sizes,
however: Xft fonts often draw glyphs larger than their acclaimed
bounding box, and rxvt-unicode has no way of detecting this (the correct
way is to ask for the character bounding box, which unfortunately is
wrong in these cases).

It's not clear (to me at least), whether this is a bug in Xft, freetype,
or the respective font. If you encounter this problem you might try
using the "-lsp" option to give the font more height. If that doesn't
work, you might be forced to use a different font.

All of this is not a problem when using X11 core fonts, as their
bounding box data is correct.

How can I keep rxvt-unicode from using reverse video so much? First of all, make sure you are running with the right terminal settings ("TERM=rxvt-unicode"), which will get rid of most of these effects. Then make sure you have specified colours for italic and bold, as otherwise rxvt-unicode might use reverse video to simulate the effect:

   URxvt.colorBD:  white
   URxvt.colorIT:  green

Some programs assume totally weird colours (red instead of blue), how can I fix that? For some unexplainable reason, some rare programs assume a very weird colour palette when confronted with a terminal with more than the standard 8 colours (rxvt-unicode supports 88). The right fix is, of course, to fix these programs not to assume non-ISO colours without very good reasons.

In the meantime, you can either edit your "rxvt-unicode" terminfo
definition to only claim 8 colour support or use "TERM=rxvt", which will
fix colours but keep you from using other rxvt-unicode features.

Can I switch the fonts at runtime? Yes, using an escape sequence. Try something like this, which has the same effect as using the "-fn" switch, and takes effect immediately:

   printf '33]50;%s07' "9x15bold,xft:Kochi Gothic"

This is useful if you e.g. work primarily with japanese (and prefer a
japanese font), but you have to switch to chinese temporarily, where
japanese fonts would only be in your way.

You can think of this as a kind of manual ISO-2022 switching.

Why do italic characters look as if clipped? Many fonts have difficulties with italic characters and hinting. For example, the otherwise very nicely hinted font "xft:Bitstream Vera Sans Mono" completely fails in its italic face. A workaround might be to enable freetype autohinting, i.e. like this:

   URxvt.italicFont:        xft:Bitstream Vera Sans Mono:italic:autohint=true
   URxvt.boldItalicFont:    xft:Bitstream Vera Sans Mono:bold:italic:autohint=true

Can I speed up Xft rendering somehow? Yes, the most obvious way to speed it up is to avoid Xft entirely, as it is simply slow. If you still want Xft fonts you might try to disable antialiasing (by appending ":antialias=false"), which saves lots of memory and also speeds up rendering considerably.

Rxvt-unicode doesn't seem to anti-alias its fonts, what is wrong? Rxvt-unicode will use whatever you specify as a font. If it needs to fall back to its default font search list it will prefer X11 core fonts, because they are small and fast, and then use Xft fonts. It has antialiasing disabled for most of them, because the author thinks they look best that way.

If you want antialiasing, you have to specify the fonts manually.

What's with this bold/blink stuff? If no bold colour is set via "colorBD:", bold will invert text using the standard foreground colour.

For the standard background colour, blinking will actually make the text
blink when compiled with "--enable-text-blink". Without
"--enable-text-blink", the blink attribute will be ignored.

On ANSI colours, bold/blink attributes are used to set high-intensity
foreground/background colors.

color0-7 are the low-intensity colors.

color8-15 are the corresponding high-intensity colors.

I don't like the screen colors. How do I change them? You can change the screen colors at run-time using ~/.Xdefaults resources (or as long-options).

Here are values that are supposed to resemble a VGA screen, including
the murky brown that passes for low-intensity yellow:

   URxvt.color0:   #000000
   URxvt.color1:   #A80000
   URxvt.color2:   #00A800
   URxvt.color3:   #A8A800
   URxvt.color4:   #0000A8
   URxvt.color5:   #A800A8
   URxvt.color6:   #00A8A8
   URxvt.color7:   #A8A8A8

   URxvt.color8:   #000054
   URxvt.color9:   #FF0054
   URxvt.color10:  #00FF54
   URxvt.color11:  #FFFF54
   URxvt.color12:  #0000FF
   URxvt.color13:  #FF00FF
   URxvt.color14:  #00FFFF
   URxvt.color15:  #FFFFFF

And here is a more complete set of non-standard colors.

   URxvt.cursorColor:  #dc74d1
   URxvt.pointerColor: #dc74d1
   URxvt.background:   #0e0e0e
   URxvt.foreground:   #4ad5e1
   URxvt.color0:       #000000
   URxvt.color8:       #8b8f93
   URxvt.color1:       #dc74d1
   URxvt.color9:       #dc74d1
   URxvt.color2:       #0eb8c7
   URxvt.color10:      #0eb8c7
   URxvt.color3:       #dfe37e
   URxvt.color11:      #dfe37e
   URxvt.color5:       #9e88f0
   URxvt.color13:      #9e88f0
   URxvt.color6:       #73f7ff
   URxvt.color14:      #73f7ff
   URxvt.color7:       #e1dddd
   URxvt.color15:      #e1dddd

They have been described (not by me) as "pretty girly".

Why do some characters look so much different than others? See next entry.

How does rxvt-unicode choose fonts? Most fonts do not contain the full range of Unicode, which is fine. Chances are that the font you (or the admin/package maintainer of your system/os) have specified does not cover all the characters you want to display.

rxvt-unicode makes a best-effort try at finding a replacement font.
Often the result is fine, but sometimes the chosen font looks
bad/ugly/wrong. Some fonts have totally strange characters that don't
resemble the correct glyph at all, and rxvt-unicode lacks the artificial
intelligence to detect that a specific glyph is wrong: it has to believe
the font that the characters it claims to contain indeed look correct.

In that case, select a font of your taste and add it to the font list,
e.g.:

   urxvt -fn basefont,font2,font3...

When rxvt-unicode sees a character, it will first look at the base font.
If the base font does not contain the character, it will go to the next
font, and so on. Specifying your own fonts will also speed up this
search and use less resources within rxvt-unicode and the X-server.

The only limitation is that none of the fonts may be larger than the
base font, as the base font defines the terminal character cell size,
which must be the same due to the way terminals work.

Why do some chinese characters look so different than others? This is because there is a difference between script and language -- rxvt-unicode does not know which language the text that is output is, as it only knows the unicode character codes. If rxvt-unicode first sees a japanese/chinese character, it might choose a japanese font for display. Subsequent japanese characters will use that font. Now, many chinese characters aren't represented in japanese fonts, so when the first non-japanese character comes up, rxvt-unicode will look for a chinese font -- unfortunately at this point, it will still use the japanese font for chinese characters that are also in the japanese font.

The workaround is easy: just tag a chinese font at the end of your font
list (see the previous question). The key is to view the font list as a
preference list: If you expect more japanese, list a japanese font
first. If you expect more chinese, put a chinese font first.

In the future it might be possible to switch language preferences at
runtime (the internal data structure has no problem with using different
fonts for the same character at the same time, but no interface for this
has been designed yet).

Until then, you might get away with switching fonts at runtime (see "Can
I switch the fonts at runtime?" later in this document).

How can I make mplayer display video correctly? We are working on it, in the meantime, as a workaround, use something like:

   urxvt -b 600 -geometry 20x1 -e sh -c 'mplayer -wid $WINDOWID file...'

Keyboard, Mouse & User Interaction The new selection selects pieces that are too big, how can I select single words? If you want to select e.g. alphanumeric words, you can use the following setting:

   URxvt.selection.pattern-0: ([[:word:]]+)

If you click more than twice, the selection will be extended more and
more.

To get a selection that is very similar to the old code, try this
pattern:

   URxvt.selection.pattern-0: ([^"&'()*,;<=>?@[\]^`{|})]+)

Please also note that the *LeftClick Shift-LeftClick* combination also
selects words like the old code.

I don't like the new selection/popups/hotkeys/perl, how do I change/disable it? You can disable the perl extension completely by setting the perl-ext-common resource to the empty string, which also keeps rxvt-unicode from initialising perl, saving memory.

If you only want to disable specific features, you first have to
identify which perl extension is responsible. For this, read the section
PREPACKAGED EXTENSIONS in the urxvtperl(3) manpage. For example, to
disable the selection-popup and option-popup, specify this
perl-ext-common resource:

   URxvt.perl-ext-common: default,-selection-popup,-option-popup

This will keep the default extensions, but disable the two popup
extensions. Some extensions can also be configured, for example,
scrollback search mode is triggered by M-s. You can move it to any other
combination either by setting the searchable-scrollback resource:

   URxvt.searchable-scrollback: CM-s

The cursor moves when selecting text in the current input line, how do I switch this off? See next entry.

During rlogin/ssh/telnet/etc. sessions, clicking near the cursor outputs strange escape sequences, how do I fix this? These are caused by the "readline" perl extension. Under normal circumstances, it will move your cursor around when you click into the line that contains it. It tries hard not to do this at the wrong moment, but when running a program that doesn't parse cursor movements or in some cases during rlogin sessions, it fails to detect this properly.

You can permanently switch this feature off by disabling the "readline"
extension:

   URxvt.perl-ext-common: default,-readline

My numerical keypad acts weird and generates differing output? Some Debian GNUL/Linux users seem to have this problem, although no specific details were reported so far. It is possible that this is caused by the wrong "TERM" setting, although the details of whether and how this can happen are unknown, as "TERM=rxvt" should offer a compatible keymap. See the answer to the previous question, and please report if that helped.

My Compose (Multi_key) key is no longer working. The most common causes for this are that either your locale is not set correctly, or you specified a preeditStyle that is not supported by your input method. For example, if you specified OverTheSpot and your input method (e.g. the default input method handling Compose keys) does not support this (for instance because it is not visual), then rxvt-unicode will continue without an input method.

In this case either do not specify a preeditStyle or specify more than
one pre-edit style, such as OverTheSpot,Root,None.

I cannot type "Ctrl-Shift-2" to get an ASCII NUL character due to ISO 14755 Either try "Ctrl-2" alone (it often is mapped to ASCII NUL even on international keyboards) or simply use ISO 14755 support to your advantage, typing to get a ASCII NUL. This works for other codes, too, such as "Ctrl-Shift-1-d" to type the default telnet escape character and so on.

Mouse cut/paste suddenly no longer works. Make sure that mouse reporting is actually turned off since killing some editors prematurely may leave the mouse in mouse report mode. I've heard that tcsh may use mouse reporting unless it otherwise specified. A quick check is to see if cut/paste works when the Alt or Shift keys are depressed.

What's with the strange Backspace/Delete key behaviour? Assuming that the physical Backspace key corresponds to the Backspace keysym (not likely for Linux ... see the following question) there are two standard values that can be used for Backspace: "^H" and "^?".

Historically, either value is correct, but rxvt-unicode adopts the
debian policy of using "^?" when unsure, because it's the one and only
correct choice :).

Rxvt-unicode tries to inherit the current stty settings and uses the
value of `erase' to guess the value for backspace. If rxvt-unicode
wasn't started from a terminal (say, from a menu or by remote shell),
then the system value of `erase', which corresponds to CERASE in
<termios.h>, will be used (which may not be the same as your stty
setting).

For starting a new rxvt-unicode:

   # use Backspace = ^H
   $ stty erase ^H
   $ urxvt

   # use Backspace = ^?
   $ stty erase ^?
   $ urxvt

Toggle with "ESC [ 36 h" / "ESC [ 36 l".

For an existing rxvt-unicode:

   # use Backspace = ^H
   $ stty erase ^H
   $ echo -n "^[[36h"

   # use Backspace = ^?
   $ stty erase ^?
   $ echo -n "^[[36l"

This helps satisfy some of the Backspace discrepancies that occur, but
if you use Backspace = "^H", make sure that the termcap/terminfo value
properly reflects that.

The Delete key is a another casualty of the ill-defined Backspace
problem. To avoid confusion between the Backspace and Delete keys, the
Delete key has been assigned an escape sequence to match the vt100 for
Execute ("ESC [ 3 ~") and is in the supplied termcap/terminfo.

Some other Backspace problems:

some editors use termcap/terminfo, some editors (vim I'm told) expect
Backspace = ^H, GNU Emacs (and Emacs-like editors) use ^H for help.

Perhaps someday this will all be resolved in a consistent manner.

I don't like the key-bindings. How do I change them? There are some compile-time selections available via configure. Unless you have run "configure" with the "--disable-resources" option you can use the `keysym' resource to alter the keystrings associated with keysyms.

Here's an example for a URxvt session started using "urxvt -name URxvt"

   URxvt.keysym.Home:          33[1~
   URxvt.keysym.End:           33[4~
   URxvt.keysym.C-apostrophe:  33<C-'>
   URxvt.keysym.C-slash:       33<C-/>
   URxvt.keysym.C-semicolon:   33<C-;>
   URxvt.keysym.C-grave:       33<C-`>
   URxvt.keysym.C-comma:       33<C-,>
   URxvt.keysym.C-period:      33<C-.>
   URxvt.keysym.C-0x60:        33<C-`>
   URxvt.keysym.C-Tab:         33<C-Tab>
   URxvt.keysym.C-Return:      33<C-Return>
   URxvt.keysym.S-Return:      33<S-Return>
   URxvt.keysym.S-space:       33<S-Space>
   URxvt.keysym.M-Up:          33<M-Up>
   URxvt.keysym.M-Down:        33<M-Down>
   URxvt.keysym.M-Left:        33<M-Left>
   URxvt.keysym.M-Right:       33<M-Right>
   URxvt.keysym.M-C-0:         list 33<M-C- 0123456789 >
   URxvt.keysym.M-C-a:         list 33<M-C- abcdefghijklmnopqrstuvwxyz >
   URxvt.keysym.F12:           command:33]701;zh_CN.GBK07

See some more examples in the documentation for the keysym resource.

I'm using keyboard model XXX that has extra Prior/Next/Insert keys. How do I make use of them? For example, the Sun Keyboard type 4 has the following map KP_Insert == Insert F22 == Print F27 == Home F29 == Prior F33 == End F35 == Next

Rather than have rxvt-unicode try to accommodate all the various
possible keyboard mappings, it is better to use `xmodmap' to remap the
keys as required for your particular machine.

Terminal Configuration Can I see a typical configuration? The default configuration tries to be xterm-like, which I don't like that much, but it's least surprise to regular users.

As a rxvt or rxvt-unicode user, you are practically supposed to invest
time into customising your terminal. To get you started, here is the
author's .Xdefaults entries, with comments on what they do. It's
certainly not *typical*, but what's typical...

   URxvt.cutchars: "()*,<>[]{}|'
   URxvt.print-pipe: cat >/tmp/xxx

These are just for testing stuff.

   URxvt.imLocale: ja_JP.UTF-8
   URxvt.preeditType: OnTheSpot,None

This tells rxvt-unicode to use a special locale when communicating with
the X Input Method, and also tells it to only use the OnTheSpot pre-edit
type, which requires the "xim-onthespot" perl extension but rewards me
with correct-looking fonts.

   URxvt.perl-lib: /root/lib/urxvt
   URxvt.perl-ext-common: default,selection-autotransform,selection-pastebin,xim-onthespot,remote-clipboard
   URxvt.selection.pattern-0: ( at .*? line d+)
   URxvt.selection.pattern-1: ^(/[^:]+): 
   URxvt.selection-autotransform.0: s/^([^:[:space:]]+):(d+):?$/:e Q$1Ex0d:$2x0d/
   URxvt.selection-autotransform.1: s/^ at (.*?) line (d+)$/:e Q$1Ex0d:$2x0d/

This is my perl configuration. The first two set the perl library
directory and also tells urxvt to use a large number of extensions. I
develop for myself mostly, so I actually use most of the extensions I
write.

The selection stuff mainly makes the selection perl-error-message aware
and tells it to convert perl error messages into vi-commands to load the
relevant file and go tot he error line number.

   URxvt.scrollstyle:      plain
   URxvt.secondaryScroll:  true

As the documentation says: plain is the preferred scrollbar for the
author. The "secondaryScroll" configures urxvt to scroll in full-screen
apps, like screen, so lines scrolled out of screen end up in urxvt's
scrollback buffer.

   URxvt.background:       #000000
   URxvt.foreground:       gray90
   URxvt.color7:           gray90
   URxvt.colorBD:          #ffffff
   URxvt.cursorColor:      #e0e080
   URxvt.throughColor:     #8080f0
   URxvt.highlightColor:   #f0f0f0

Some colours. Not sure which ones are being used or even non-defaults,
but these are in my .Xdefaults. Most notably, they set
foreground/background to light gray/black, and also make sure that the
colour 7 matches the default foreground colour.

   URxvt.underlineColor:   yellow

Another colour, makes underline lines look different. Sometimes hurts,
but is mostly a nice effect.

   URxvt.geometry:         154x36
   URxvt.loginShell:       false
   URxvt.meta:             ignore
   URxvt.utmpInhibit:      true

Uh, well, should be mostly self-explanatory. By specifying some defaults
manually, I can quickly switch them for testing.

   URxvt.saveLines:        8192

A large scrollback buffer is essential. Really.

   URxvt.mapAlert:         true

The only case I use it is for my IRC window, which I like to keep
iconified till people msg me (which beeps).

   URxvt.visualBell:       true

The audible bell is often annoying, especially when in a crowd.

   URxvt.insecure:         true

Please don't hack my mutt! Ooops...

   URxvt.pastableTabs:     false

I once thought this is a great idea.

   urxvt.font:             9x15bold,
                           -misc-fixed-bold-r-normal--15-140-75-75-c-90-iso10646-1,
                           -misc-fixed-medium-r-normal--15-140-75-75-c-90-iso10646-1, 
                           [codeset=JISX0208]xft:Kochi Gothic, 
                           xft:Bitstream Vera Sans Mono:autohint=true, 
                           xft:Code2000:antialias=false
   urxvt.boldFont:         -xos4-terminus-bold-r-normal--14-140-72-72-c-80-iso8859-15
   urxvt.italicFont:       xft:Bitstream Vera Sans Mono:italic:autohint=true
   urxvt.boldItalicFont:   xft:Bitstream Vera Sans Mono:bold:italic:autohint=true

I wrote rxvt-unicode to be able to specify fonts exactly. So don't be
overwhelmed. A special note: the "9x15bold" mentioned above is actually
the version from XFree-3.3, as XFree-4 replaced it by a totally
different font (different glyphs for ";" and many other harmless
characters), while the second font is actually the "9x15bold" from
XFree4/XOrg. The bold version has less chars than the medium version, so
I use it for rare characters, too. When editing sources with vim, I use
italic for comments and other stuff, which looks quite good with
Bitstream Vera anti-aliased.

Terminus is a quite bad font (many very wrong glyphs), but for most of
my purposes, it works, and gives a different look, as my normal
(Non-bold) font is already bold, and I want to see a difference between
bold and normal fonts.

Please note that I used the "urxvt" instance name and not the "URxvt"
class name. Thats because I use different configs for different
purposes, for example, my IRC window is started with "-name IRC", and
uses these defaults:

   IRC*title:              IRC
   IRC*geometry:           87x12+535+542
   IRC*saveLines:          0
   IRC*mapAlert:           true
   IRC*font:               suxuseuro
   IRC*boldFont:           suxuseuro
   IRC*colorBD:            white
   IRC*keysym.M-C-1:       command:33]710;suxuseuro0733]711;suxuseuro07
   IRC*keysym.M-C-2:       command:33]710;9x15bold0733]711;9x15bold07

"Alt-Shift-1" and "Alt-Shift-2" switch between two different font sizes.
"suxuseuro" allows me to keep an eye (and actually read) stuff while
keeping a very small window. If somebody pastes something complicated
(e.g. japanese), I temporarily switch to a larger font.

The above is all in my ".Xdefaults" (I don't use ".Xresources" nor
"xrdb"). I also have some resources in a separate ".Xdefaults-hostname"
file for different hosts, for example, on ym main desktop, I use:

   URxvt.keysym.C-M-q: command:33[3;5;5t
   URxvt.keysym.C-M-y: command:33[3;5;606t
   URxvt.keysym.C-M-e: command:33[3;1605;5t
   URxvt.keysym.C-M-c: command:33[3;1605;606t
   URxvt.keysym.C-M-p: perl:test

The first for keysym definitions allow me to quickly bring some windows
in the layout I like most. Ion users might start laughing but will stop
immediately when I tell them that I use my own Fvwm2 module for much the
same effect as Ion provides, and I only very rarely use the above key
combinations :->

Why doesn't rxvt-unicode read my resources? Well, why, indeed? It does, in a way very similar to other X applications. Most importantly, this means that if you or your OS loads resources into the X display (the right way to do it), rxvt-unicode will ignore any resource files in your home directory. It will only read $HOME/.Xdefaults when no resources are attached to the display.

If you have or use an $HOME/.Xresources file, chances are that resources
are loaded into your X-server. In this case, you have to re-login after
every change (or run xrdb -merge $HOME/.Xresources).

Also consider the form resources have to use:

  URxvt.resource: value

If you want to use another form (there are lots of different ways of
specifying resources), make sure you understand whether and why it
works. If unsure, use the form above.

When I log-in to another system it tells me about missing terminfo data? The terminal description used by rxvt-unicode is not as widely available as that for xterm, or even rxvt (for which the same problem often arises).

The correct solution for this problem is to install the terminfo, this
can be done like this (with ncurses' infocmp and works as user and
admin):

   REMOTE=remotesystem.domain
   infocmp rxvt-unicode | ssh $REMOTE "mkdir -p .terminfo && cat >/tmp/ti && tic /tmp/ti"

... or by installing rxvt-unicode normally on the remote system,

One some systems you might need to set $TERMINFO to the full path of
$HOME/.terminfo for this to work.

If you cannot or do not want to do this, then you can simply set
"TERM=rxvt" or even "TERM=xterm", and live with the small number of
problems arising, which includes wrong keymapping, less and different
colours and some refresh errors in fullscreen applications. It's a nice
quick-and-dirty workaround for rare cases, though.

If you always want to do this (and are fine with the consequences) you
can either recompile rxvt-unicode with the desired TERM value or use a
resource to set it:

   URxvt.termName: rxvt

If you don't plan to use rxvt (quite common...) you could also replace
the rxvt terminfo file with the rxvt-unicode one and use "TERM=rxvt".

"tic" outputs some error when compiling the terminfo entry. Most likely it's the empty definition for "enacs=". Just replace it by "enacs=E[0@" and try again.

"bash"'s readline does not work correctly under urxvt. See next entry.

I need a termcap file entry. One reason you might want this is that some distributions or operating systems still compile some programs using the long-obsoleted termcap library (Fedora Core's bash is one example) and rely on a termcap entry for "rxvt-unicode".

You could use rxvt's termcap entry with reasonable results in many
cases. You can also create a termcap entry by using terminfo's infocmp
program like this:

   infocmp -C rxvt-unicode

Or you could use the termcap entry in doc/etc/rxvt-unicode.termcap,
generated by the command above.

Why does "ls" no longer have coloured output? The "ls" in the GNU coreutils unfortunately doesn't use terminfo to decide whether a terminal has colour, but uses its own configuration file. Needless to say, "rxvt-unicode" is not in its default file (among with most other terminals supporting colour). Either add:

   TERM rxvt-unicode

to "/etc/DIR_COLORS" or simply add:

   alias ls='ls --color=auto'

to your ".profile" or ".bashrc".

Why doesn't vim/emacs etc. use the 88 colour mode? See next entry.

Why doesn't vim/emacs etc. make use of italic? See next entry.

Why are the secondary screen-related options not working properly? Make sure you are using "TERM=rxvt-unicode". Some pre-packaged distributions (most notably Debian GNU/Linux) break rxvt-unicode by setting "TERM" to "rxvt", which doesn't have these extra features. Unfortunately, some of these (most notably, again, Debian GNU/Linux) furthermore fail to even install the "rxvt-unicode" terminfo file, so you will need to install it on your own (See the question When I log-in to another system it tells me about missing terminfo data? on how to do this).

Encoding / Locale / Input Method Issues Rxvt-unicode does not seem to understand the selected encoding? See next entry.

Unicode does not seem to work? If you encounter strange problems like typing an accented character but getting two unrelated other characters or similar, or if program output is subtly garbled, then you should check your locale settings.

Rxvt-unicode must be started with the same "LC_CTYPE" setting as the
programs running in it. Often rxvt-unicode is started in the "C" locale,
while the login script running within the rxvt-unicode window changes
the locale to something else, e.g. "en_GB.UTF-8". Needless to say, this
is not going to work, and is the most common cause for problems.

The best thing is to fix your startup environment, as you will likely
run into other problems. If nothing works you can try this in your
.profile.

  printf '33]701;%s07' "$LC_CTYPE"   # $LANG or $LC_ALL are worth a try, too

If this doesn't work, then maybe you use a "LC_CTYPE" specification not
supported on your systems. Some systems have a "locale" command which
displays this (also, "perl -e0" can be used to check locale settings, as
it will complain loudly if it cannot set the locale). If it displays
something like:

  locale: Cannot set LC_CTYPE to default locale: ...

Then the locale you specified is not supported on your system.

If nothing works and you are sure that everything is set correctly then
you will need to remember a little known fact: Some programs just don't
support locales :(

How does rxvt-unicode determine the encoding to use? See next entry.

Is there an option to switch encodings? Unlike some other terminals, rxvt-unicode has no encoding switch, and no specific "utf-8" mode, such as xterm. In fact, it doesn't even know about UTF-8 or any other encodings with respect to terminal I/O.

The reasons is that there exists a perfectly fine mechanism for
selecting the encoding, doing I/O and (most important) communicating
this to all applications so everybody agrees on character properties
such as width and code number. This mechanism is the *locale*.
Applications not using that info will have problems (for example,
"xterm" gets the width of characters wrong as it uses its own,
locale-independent table under all locales).

Rxvt-unicode uses the "LC_CTYPE" locale category to select encoding. All
programs doing the same (that is, most) will automatically agree in the
interpretation of characters.

Unfortunately, there is no system-independent way to select locales, nor
is there a standard on how locale specifiers will look like.

On most systems, the content of the "LC_CTYPE" environment variable
contains an arbitrary string which corresponds to an already-installed
locale. Common names for locales are "en_US.UTF-8", "de_DE.ISO-8859-15",
"ja_JP.EUC-JP", i.e. "language_country.encoding", but other forms (i.e.
"de" or "german") are also common.

Rxvt-unicode ignores all other locale categories, and except for the
encoding, ignores country or language-specific settings, i.e.
"de_DE.UTF-8" and "ja_JP.UTF-8" are the normally same to rxvt-unicode.

If you want to use a specific encoding you have to make sure you start
rxvt-unicode with the correct "LC_CTYPE" category.

Can I switch locales at runtime? Yes, using an escape sequence. Try something like this, which sets rxvt-unicode's idea of "LC_CTYPE".

  printf '33]701;%s07' ja_JP.SJIS

See also the previous answer.

Sometimes this capability is rather handy when you want to work in one
locale (e.g. "de_DE.UTF-8") but some programs don't support it (e.g.
UTF-8). For example, I use this script to start "xjdic", which first
switches to a locale supported by xjdic and back later:

   printf '33]701;%s07' ja_JP.SJIS
   xjdic -js
   printf '33]701;%s07' de_DE.UTF-8

You can also use xterm's "luit" program, which usually works fine,
except for some locales where character width differs between program-
and rxvt-unicode-locales.

I have problems getting my input method working. Try a search engine, as this is slightly different for every input method server.

Here is a checklist:

- Make sure your locale *and* the imLocale are supported on your OS.
    Try "locale -a" or check the documentation for your OS.

- Make sure your locale or imLocale matches a locale supported by your
XIM.
    For example, kinput2 does not support UTF-8 locales, you should use
    "ja_JP.EUC-JP" or equivalent.

- Make sure your XIM server is actually running.
- Make sure the "XMODIFIERS" environment variable is set correctly when
*starting* rxvt-unicode.
    When you want to use e.g. kinput2, it must be set to "@im=kinput2".
    For scim, use "@im=SCIM". You can see what input method servers are
    running with this command:

       xprop -root XIM_SERVERS

My input method wants but I want UTF-8, what can I do? You can specify separate locales for the input method and the rest of the terminal, using the resource "imlocale":

   URxvt.imlocale: ja_JP.EUC-JP

Now you can start your terminal with "LC_CTYPE=ja_JP.UTF-8" and still
use your input method. Please note, however, that, depending on your
Xlib version, you may not be able to input characters outside "EUC-JP"
in a normal way then, as your input method limits you.

Rxvt-unicode crashes when the X Input Method changes or exits. Unfortunately, this is unavoidable, as the XIM protocol is racy by design. Applications can avoid some crashes at the expense of memory leaks, and Input Methods can avoid some crashes by careful ordering at exit time. kinput2 (and derived input methods) generally succeeds, while SCIM (or similar input methods) fails. In the end, however, crashes cannot be completely avoided even if both sides cooperate.

So the only workaround is not to kill your Input Method Servers.

Operating Systems / Package Maintaining I am using Debian GNU/Linux and have a problem... The Debian GNU/Linux package of rxvt-unicode in sarge contains large patches that considerably change the behaviour of rxvt-unicode (but unfortunately this notice has been removed). Before reporting a bug to the original rxvt-unicode author please download and install the genuine version (http://software.schmorp.de#rxvt-unicode) and try to reproduce the problem. If you cannot, chances are that the problems are specific to Debian GNU/Linux, in which case it should be reported via the Debian Bug Tracking System (use "reportbug" to report the bug).

For other problems that also affect the Debian package, you can and
probably should use the Debian BTS, too, because, after all, it's also a
bug in the Debian version and it serves as a reminder for other users
that might encounter the same issue.

I am maintaining rxvt-unicode for distribution/OS XXX, any recommendation? You should build one binary with the default options. configure now enables most useful options, and the trend goes to making them runtime-switchable, too, so there is usually no drawback to enabling them, except higher disk and possibly memory usage. The perl interpreter should be enabled, as important functionality (menus, selection, likely more in the future) depends on it.

You should not overwrite the "perl-ext-common" snd "perl-ext" resources
system-wide (except maybe with "defaults"). This will result in useful
behaviour. If your distribution aims at low memory, add an empty
"perl-ext-common" resource to the app-defaults file. This will keep the
perl interpreter disabled until the user enables it.

If you can/want build more binaries, I recommend building a minimal one
with "--disable-everything" (very useful) and a maximal one with
"--enable-everything" (less useful, it will be very big due to a lot of
encodings built-in that increase download times and are rarely used).

I need to make it setuid/setgid to support utmp/ptys on my OS, is this safe? It should be, starting with release 7.1. You are encouraged to properly install urxvt with privileges necessary for your OS now.

When rxvt-unicode detects that it runs setuid or setgid, it will fork
into a helper process for privileged operations (pty handling on some
systems, utmp/wtmp/lastlog handling on others) and drop privileges
immediately. This is much safer than most other terminals that keep
privileges while running (but is more relevant to urxvt, as it contains
things as perl interpreters, which might be "helpful" to attackers).

This forking is done as the very first within main(), which is very
early and reduces possible bugs to initialisation code run before
main(), or things like the dynamic loader of your system, which should
result in very little risk.

I am on FreeBSD and rxvt-unicode does not seem to work at all. Rxvt-unicode requires the symbol "STDC_ISO_10646" to be defined in your compile environment, or an implementation that implements it, whether it defines the symbol or not. "STDC_ISO_10646" requires that wchar_t is represented as unicode.

As you might have guessed, FreeBSD does neither define this symbol nor
does it support it. Instead, it uses its own internal representation of
wchar_t. This is, of course, completely fine with respect to standards.

However, that means rxvt-unicode only works in "POSIX", "ISO-8859-1" and
"UTF-8" locales under FreeBSD (which all use Unicode as wchar_t).

"__STDC_ISO_10646__" is the only sane way to support multi-language apps
in an OS, as using a locale-dependent (and non-standardized)
representation of wchar_t makes it impossible to convert between wchar_t
(as used by X11 and your applications) and any other encoding without
implementing OS-specific-wrappers for each and every locale. There
simply are no APIs to convert wchar_t into anything except the current
locale encoding.

Some applications (such as the formidable mlterm) work around this by
carrying their own replacement functions for character set handling with
them, and either implementing OS-dependent hacks or doing multiple
conversions (which is slow and unreliable in case the OS implements
encodings slightly different than the terminal emulator).

The rxvt-unicode author insists that the right way to fix this is in the
system libraries once and for all, instead of forcing every app to carry
complete replacements for them :)

How can I use rxvt-unicode under cygwin? rxvt-unicode should compile and run out of the box on cygwin, using the X11 libraries that come with cygwin. libW11 emulation is no longer supported (and makes no sense, either, as it only supported a single font). I recommend starting the X-server in "-multiwindow" or "-rootless" mode instead, which will result in similar look&feel as the old libW11 emulation.

At the time of this writing, cygwin didn't seem to support any
multi-byte encodings (you might try "LC_CTYPE=C-UTF-8"), so you are
likely limited to 8-bit encodings.

Character widths are not correct. urxvt uses the system wcwidth function to know the information about the width of characters, so on systems with incorrect locale data you will likely get bad results. Two notorious examples are Solaris 9, where single-width characters like U+2514 are reported as double-width, and Darwin 8, where combining chars are reported having width 1.

The solution is to upgrade your system or switch to a better one. A
possibly working workaround is to use a wcwidth implementation like

http://www.cl.cam.ac.uk/~mgk25/ucs/wcwidth.c