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[dana/urxvt.git] / README.FAQ

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 :).

   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 do I distinguish wether I'm running rxvt-unicode or a regular xterm? I need this to decide about setting colors etc.
    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 <cblake@BBN.COM> 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 pod2html. 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 unreasnobaly 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, transparency isn't officially supported in rxvt-unicode,
    so you are mostly on your own. Do not bug the author about it (but you
    may bug everybody else). 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 inheritPixmap:

       Esetroot wallpaper.jpg
       urxvt -ip -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.xpm
       urxvt -pixmap background.xpm -pe automove-background

    That works. If you think it doesn't, you lack XPM and Perl 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
    neccessary 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 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).

   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), wether 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 '\e]50;%s\007' "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 it's 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 it's 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-blinking". with standard colours.
    Without "--enable-blinking", 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 described (not by
    me) as "pretty girly".

       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

   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.

  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-LeftClik* 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 permamently 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 wether 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 <Ctrl-Shift-0> 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 only 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:          \033[1~
       URxvt.keysym.End:           \033[4~
       URxvt.keysym.C-apostrophe:  \033<C-'>
       URxvt.keysym.C-slash:       \033<C-/>
       URxvt.keysym.C-semicolon:   \033<C-;>
       URxvt.keysym.C-grave:       \033<C-`>
       URxvt.keysym.C-comma:       \033<C-,>
       URxvt.keysym.C-period:      \033<C-.>
       URxvt.keysym.C-0x60:        \033<C-`>
       URxvt.keysym.C-Tab:         \033<C-Tab>
       URxvt.keysym.C-Return:      \033<C-Return>
       URxvt.keysym.S-Return:      \033<S-Return>
       URxvt.keysym.S-space:       \033<S-Space>
       URxvt.keysym.M-Up:          \033<M-Up>
       URxvt.keysym.M-Down:        \033<M-Down>
       URxvt.keysym.M-Left:        \033<M-Left>
       URxvt.keysym.M-Right:       \033<M-Right>
       URxvt.keysym.M-C-0:         list \033<M-C- 0123456789 >
       URxvt.keysym.M-C-a:         list \033<M-C- abcdefghijklmnopqrstuvwxyz >
       URxvt.keysym.F12:           command:\033]701;zh_CN.GBK\007

    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
   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 wether 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):

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

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

    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.

   "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 resonable 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 this termcap entry, generated by the command above:

       rxvt-unicode|rxvt-unicode terminal (X Window System):\
               :am:bw:eo:km:mi:ms:xn:xo:\
               :co#80:it#8:li#24:lm#0:\
               :AL=\E[%dL:DC=\E[%dP:DL=\E[%dM:DO=\E[%dB:IC=\E[%d@:\
               :K1=\EOw:K2=\EOu:K3=\EOy:K4=\EOq:K5=\EOs:LE=\E[%dD:\
               :RI=\E[%dC:SF=\E[%dS:SR=\E[%dT:UP=\E[%dA:ae=\E(B:al=\E[L:\
               :as=\E(0:bl=^G:cd=\E[J:ce=\E[K:cl=\E[H\E[2J:\
               :cm=\E[%i%d;%dH:cr=^M:cs=\E[%i%d;%dr:ct=\E[3g:dc=\E[P:\
               :dl=\E[M:do=^J:ec=\E[%dX:ei=\E[4l:ho=\E[H:\
               :i1=\E[?47l\E=\E[?1l:ic=\E[@:im=\E[4h:\
               :is=\E[r\E[m\E[2J\E[H\E[?7h\E[?1;3;4;6l\E[4l:\
               :k1=\E[11~:k2=\E[12~:k3=\E[13~:k4=\E[14~:k5=\E[15~:\
               :k6=\E[17~:k7=\E[18~:k8=\E[19~:k9=\E[20~:kD=\E[3~:\
               :kI=\E[2~:kN=\E[6~:kP=\E[5~:kb=\177:kd=\EOB:ke=\E[?1l\E>:\
               :kh=\E[7~:kl=\EOD:kr=\EOC:ks=\E[?1h\E=:ku=\EOA:le=^H:\
               :mb=\E[5m:md=\E[1m:me=\E[m\017:mr=\E[7m:nd=\E[C:rc=\E8:\
               :sc=\E7:se=\E[27m:sf=^J:so=\E[7m:sr=\EM:st=\EH:ta=^I:\
               :te=\E[r\E[?1049l:ti=\E[?1049h:ue=\E[24m:up=\E[A:\
               :us=\E[4m:vb=\E[?5h\E[?5l:ve=\E[?25h:vi=\E[?25l:\
               :vs=\E[?25h:

   Why does "ls" no longer have coloured output?
    The "ls" in the GNU coreutils unfortunately doesn't use terminfo to
    decide wether a terminal has colour, but uses it's own configuration
    file. Needless to say, "rxvt-unicode" is not in it's 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. 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.

    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 '\e]701;%s\007' "$LC_CTYPE"

    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 it's 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 '\e]701;%s\007' 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 '\e]701;%s\007' ja_JP.SJIS
       xjdic -js
       printf '\e]701;%s\007' 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.

   My input method wants <some encoding> 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 you will 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 enbaling
    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.

   On Solaris 9, many line-drawing characters are too wide.
    Seems to be a known bug, read
    <http://nixdoc.net/files/forum/about34198.html>. Some people use the
    following ugly workaround to get non-double-wide-characters working:

       #define wcwidth(x) wcwidth(x) > 1 ? 1 : wcwidth(x)

   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,
    wether 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 symobl nor
    does it support it. Instead, it uses it's 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 :)

   I use Solaris 9 and it doesn't compile/work/etc.
    Try the diff in doc/solaris9.patch as a base. It fixes the worst
    problems with "wcwidth" and a compile problem.

   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.