ViewVC Help
View File | Revision Log | Show Annotations | Download File
/cvs/rxvt-unicode/README.FAQ
Revision: 1.56
Committed: Tue Nov 4 23:00:43 2008 UTC (15 years, 6 months ago) by root
Branch: MAIN
CVS Tags: rel-9_06
Changes since 1.55: +11 -0 lines
Log Message:
*** empty log message ***

File Contents

# User Rev Content
1 root 1.42 RXVT-UNICODE/URXVT FREQUENTLY ASKED QUESTIONS
2     Meta, Features & Commandline Issues
3     My question isn't answered here, can I ask a human?
4     Before sending me mail, you could go to IRC: "irc.freenode.net", channel
5     "#rxvt-unicode" has some rxvt-unicode enthusiasts that might be
6     interested in learning about new and exciting problems (but not FAQs :).
7    
8 root 1.56 I use Gentoo, and I have a problem...
9     There are three big problems with Gentoo Linux: first of all, most if
10     not all Gentoo systems are completely broken (missing or mismatched
11     header files, broken compiler etc. are just the tip of the iceberg);
12     secondly, the Gentoo maintainer thinks it is a good idea to add broken
13     patches to the code; and lastly, it should be called Gentoo GNU/Linux.
14    
15     For these reasons, it is impossible to support rxvt-unicode on Gentoo.
16     Problems appearing on Gentoo systems will usually simply be ignored
17     unless they can be reproduced on non-Gentoo systems.
18    
19 root 1.42 Does it support tabs, can I have a tabbed rxvt-unicode?
20     Beginning with version 7.3, there is a perl extension that implements a
21     simple tabbed terminal. It is installed by default, so any of these
22     should give you tabs:
23    
24     urxvt -pe tabbed
25    
26     URxvt.perl-ext-common: default,tabbed
27    
28     It will also work fine with tabbing functionality of many window
29     managers or similar tabbing programs, and its embedding-features allow
30     it to be embedded into other programs, as witnessed by doc/rxvt-tabbed
31     or the upcoming "Gtk2::URxvt" perl module, which features a tabbed urxvt
32     (murxvt) terminal as an example embedding application.
33    
34     How do I know which rxvt-unicode version I'm using?
35     The version number is displayed with the usage (-h). Also the escape
36     sequence "ESC [ 8 n" sets the window title to the version number. When
37     using the urxvtc client, the version displayed is that of the daemon.
38    
39     Rxvt-unicode uses gobs of memory, how can I reduce that?
40     Rxvt-unicode tries to obey the rule of not charging you for something
41     you don't use. One thing you should try is to configure out all settings
42     that you don't need, for example, Xft support is a resource hog by
43     design, when used. Compiling it out ensures that no Xft font will be
44     loaded accidentally when rxvt-unicode tries to find a font for your
45     characters.
46    
47     Also, many people (me included) like large windows and even larger
48     scrollback buffers: Without "--enable-unicode3", rxvt-unicode will use 6
49     bytes per screen cell. For a 160x?? window this amounts to almost a
50     kilobyte per line. A scrollback buffer of 10000 lines will then (if
51     full) use 10 Megabytes of memory. With "--enable-unicode3" it gets
52     worse, as rxvt-unicode then uses 8 bytes per screen cell.
53    
54     How can I start urxvtd in a race-free way?
55     Try "urxvtd -f -o", which tells urxvtd to open the display, create the
56     listening socket and then fork.
57    
58 root 1.45 How can I start urxvtd automatically when I run urxvtc?
59 root 1.42 If you want to start urxvtd automatically whenever you run urxvtc and
60     the daemon isn't running yet, use this script:
61    
62     #!/bin/sh
63     urxvtc "$@"
64     if [ $? -eq 2 ]; then
65     urxvtd -q -o -f
66     urxvtc "$@"
67     fi
68    
69     This tries to create a new terminal, and if fails with exit status 2,
70     meaning it couldn't connect to the daemon, it will start the daemon and
71     re-run the command. Subsequent invocations of the script will re-use the
72     existing daemon.
73    
74 root 1.43 How do I distinguish whether I'm running rxvt-unicode or a regular xterm? I need this to decide about setting colors etc.
75 root 1.42 The original rxvt and rxvt-unicode always export the variable
76     "COLORTERM", so you can check and see if that is set. Note that several
77     programs, JED, slrn, Midnight Commander automatically check this
78     variable to decide whether or not to use color.
79    
80     How do I set the correct, full IP address for the DISPLAY variable?
81     If you've compiled rxvt-unicode with DISPLAY_IS_IP and have enabled
82     insecure mode then it is possible to use the following shell script
83     snippets to correctly set the display. If your version of rxvt-unicode
84     wasn't also compiled with ESCZ_ANSWER (as assumed in these snippets)
85     then the COLORTERM variable can be used to distinguish rxvt-unicode from
86     a regular xterm.
87    
88     Courtesy of Chuck Blake <cblake@BBN.COM> with the following shell script
89     snippets:
90    
91     # Bourne/Korn/POSIX family of shells:
92     [ ${TERM:-foo} = foo ] && TERM=xterm # assume an xterm if we don't know
93     if [ ${TERM:-foo} = xterm ]; then
94     stty -icanon -echo min 0 time 15 # see if enhanced rxvt or not
95     echo -n '^[Z'
96     read term_id
97     stty icanon echo
98     if [ ""${term_id} = '^[[?1;2C' -a ${DISPLAY:-foo} = foo ]; then
99     echo -n '^[[7n' # query the rxvt we are in for the DISPLAY string
100     read DISPLAY # set it in our local shell
101     fi
102     fi
103    
104     How do I compile the manual pages on my own?
105     You need to have a recent version of perl installed as /usr/bin/perl,
106 root 1.49 one that comes with pod2man, pod2text and pod2xhtml (from Pod::Xhtml).
107 root 1.48 Then go to the doc subdirectory and enter "make alldoc".
108 root 1.42
109     Isn't rxvt-unicode supposed to be small? Don't all those features bloat?
110     I often get asked about this, and I think, no, they didn't cause extra
111     bloat. If you compare a minimal rxvt and a minimal urxvt, you can see
112     that the urxvt binary is larger (due to some encoding tables always
113     being compiled in), but it actually uses less memory (RSS) after
114     startup. Even with "--disable-everything", this comparison is a bit
115     unfair, as many features unique to urxvt (locale, encoding conversion,
116     iso14755 etc.) are already in use in this mode.
117    
118     text data bss drs rss filename
119     98398 1664 24 15695 1824 rxvt --disable-everything
120     188985 9048 66616 18222 1788 urxvt --disable-everything
121    
122     When you "--enable-everything" (which *is* unfair, as this involves xft
123     and full locale/XIM support which are quite bloaty inside libX11 and my
124 root 1.43 libc), the two diverge, but not unreasonably so.
125 root 1.42
126     text data bss drs rss filename
127     163431 2152 24 20123 2060 rxvt --enable-everything
128     1035683 49680 66648 29096 3680 urxvt --enable-everything
129    
130     The very large size of the text section is explained by the east-asian
131     encoding tables, which, if unused, take up disk space but nothing else
132     and can be compiled out unless you rely on X11 core fonts that use those
133     encodings. The BSS size comes from the 64k emergency buffer that my c++
134     compiler allocates (but of course doesn't use unless you are out of
135     memory). Also, using an xft font instead of a core font immediately adds
136     a few megabytes of RSS. Xft indeed is responsible for a lot of RSS even
137     when not used.
138    
139     Of course, due to every character using two or four bytes instead of
140     one, a large scrollback buffer will ultimately make rxvt-unicode use
141     more memory.
142    
143     Compared to e.g. Eterm (5112k), aterm (3132k) and xterm (4680k), this
144     still fares rather well. And compared to some monsters like
145     gnome-terminal (21152k + extra 4204k in separate processes) or konsole
146     (22200k + extra 43180k in daemons that stay around after exit, plus half
147     a minute of startup time, including the hundreds of warnings it spits
148     out), it fares extremely well *g*.
149    
150     Why C++, isn't that unportable/bloated/uncool?
151     Is this a question? :) It comes up very often. The simple answer is: I
152     had to write it, and C++ allowed me to write and maintain it in a
153     fraction of the time and effort (which is a scarce resource for me). Put
154     even shorter: It simply wouldn't exist without C++.
155    
156     My personal stance on this is that C++ is less portable than C, but in
157     the case of rxvt-unicode this hardly matters, as its portability limits
158     are defined by things like X11, pseudo terminals, locale support and
159     unix domain sockets, which are all less portable than C++ itself.
160    
161     Regarding the bloat, see the above question: It's easy to write programs
162     in C that use gobs of memory, an certainly possible to write programs in
163     C++ that don't. C++ also often comes with large libraries, but this is
164     not necessarily the case with GCC. Here is what rxvt links against on my
165     system with a minimal config:
166    
167     libX11.so.6 => /usr/X11R6/lib/libX11.so.6 (0x00002aaaaabc3000)
168     libc.so.6 => /lib/libc.so.6 (0x00002aaaaadde000)
169     libdl.so.2 => /lib/libdl.so.2 (0x00002aaaab01d000)
170     /lib64/ld-linux-x86-64.so.2 (0x00002aaaaaaab000)
171    
172     And here is rxvt-unicode:
173    
174     libX11.so.6 => /usr/X11R6/lib/libX11.so.6 (0x00002aaaaabc3000)
175     libgcc_s.so.1 => /lib/libgcc_s.so.1 (0x00002aaaaada2000)
176 root 1.51 libc.so.6 => /lib/libc.so.6 (0x00002aaaaaeb0000)
177     libdl.so.2 => /lib/libdl.so.2 (0x00002aaaab0ee000)
178     /lib64/ld-linux-x86-64.so.2 (0x00002aaaaaaab000)
179 root 1.42
180     No large bloated libraries (of course, none were linked in statically),
181     except maybe libX11 :)
182    
183     Rendering, Font & Look and Feel Issues
184     I can't get transparency working, what am I doing wrong?
185 root 1.50 First of all, please address all transparency related issues to Sasha
186     Vasko at sasha@aftercode.net and do not bug the author about it. Also,
187     if you can't get it working consider it a rite of passage: ... and you
188     failed.
189 root 1.42
190     Here are four ways to get transparency. Do read the manpage and option
191     descriptions for the programs mentioned and rxvt-unicode. Really, do it!
192    
193 root 1.51 1. Use transparent mode:
194 root 1.42
195     Esetroot wallpaper.jpg
196 root 1.51 urxvt -tr -tint red -sh 40
197 root 1.42
198     That works. If you think it doesn't, you lack transparency and tinting
199     support, or you are unable to read.
200    
201     2. Use a simple pixmap and emulate pseudo-transparency. This enables you
202     to use effects other than tinting and shading: Just shade/tint/whatever
203     your picture with gimp or any other tool:
204    
205 root 1.50 convert wallpaper.jpg -blur 20x20 -modulate 30 background.jpg
206 root 1.51 urxvt -pixmap "background.jpg;:root"
207 root 1.42
208 root 1.51 That works. If you think it doesn't, you lack AfterImage support, or you
209     are unable to read.
210 root 1.42
211     3. Use an ARGB visual:
212    
213     urxvt -depth 32 -fg grey90 -bg rgba:0000/0000/4444/cccc
214    
215     This requires XFT support, and the support of your X-server. If that
216     doesn't work for you, blame Xorg and Keith Packard. ARGB visuals aren't
217     there yet, no matter what they claim. Rxvt-Unicode contains the
218 root 1.43 necessary bugfixes and workarounds for Xft and Xlib to make it work, but
219     that doesn't mean that your WM has the required kludges in place.
220 root 1.42
221     4. Use xcompmgr and let it do the job:
222    
223     xprop -frame -f _NET_WM_WINDOW_OPACITY 32c \
224     -set _NET_WM_WINDOW_OPACITY 0xc0000000
225    
226     Then click on a window you want to make transparent. Replace 0xc0000000
227     by other values to change the degree of opacity. If it doesn't work and
228     your server crashes, you got to keep the pieces.
229    
230     Why does rxvt-unicode sometimes leave pixel droppings?
231     Most fonts were not designed for terminal use, which means that
232     character size varies a lot. A font that is otherwise fine for terminal
233     use might contain some characters that are simply too wide. Rxvt-unicode
234     will avoid these characters. For characters that are just "a bit" too
235     wide a special "careful" rendering mode is used that redraws adjacent
236     characters.
237    
238     All of this requires that fonts do not lie about character sizes,
239     however: Xft fonts often draw glyphs larger than their acclaimed
240     bounding box, and rxvt-unicode has no way of detecting this (the correct
241     way is to ask for the character bounding box, which unfortunately is
242     wrong in these cases).
243    
244 root 1.43 It's not clear (to me at least), whether this is a bug in Xft, freetype,
245 root 1.42 or the respective font. If you encounter this problem you might try
246     using the "-lsp" option to give the font more height. If that doesn't
247     work, you might be forced to use a different font.
248    
249     All of this is not a problem when using X11 core fonts, as their
250     bounding box data is correct.
251    
252     How can I keep rxvt-unicode from using reverse video so much?
253     First of all, make sure you are running with the right terminal settings
254     ("TERM=rxvt-unicode"), which will get rid of most of these effects. Then
255     make sure you have specified colours for italic and bold, as otherwise
256     rxvt-unicode might use reverse video to simulate the effect:
257    
258     URxvt.colorBD: white
259     URxvt.colorIT: green
260    
261     Some programs assume totally weird colours (red instead of blue), how can I fix that?
262     For some unexplainable reason, some rare programs assume a very weird
263     colour palette when confronted with a terminal with more than the
264     standard 8 colours (rxvt-unicode supports 88). The right fix is, of
265     course, to fix these programs not to assume non-ISO colours without very
266     good reasons.
267    
268     In the meantime, you can either edit your "rxvt-unicode" terminfo
269     definition to only claim 8 colour support or use "TERM=rxvt", which will
270     fix colours but keep you from using other rxvt-unicode features.
271    
272     Can I switch the fonts at runtime?
273     Yes, using an escape sequence. Try something like this, which has the
274     same effect as using the "-fn" switch, and takes effect immediately:
275    
276     printf '\33]50;%s\007' "9x15bold,xft:Kochi Gothic"
277    
278     This is useful if you e.g. work primarily with japanese (and prefer a
279     japanese font), but you have to switch to chinese temporarily, where
280     japanese fonts would only be in your way.
281    
282     You can think of this as a kind of manual ISO-2022 switching.
283    
284     Why do italic characters look as if clipped?
285     Many fonts have difficulties with italic characters and hinting. For
286     example, the otherwise very nicely hinted font "xft:Bitstream Vera Sans
287     Mono" completely fails in its italic face. A workaround might be to
288     enable freetype autohinting, i.e. like this:
289    
290     URxvt.italicFont: xft:Bitstream Vera Sans Mono:italic:autohint=true
291     URxvt.boldItalicFont: xft:Bitstream Vera Sans Mono:bold:italic:autohint=true
292    
293     Can I speed up Xft rendering somehow?
294     Yes, the most obvious way to speed it up is to avoid Xft entirely, as it
295     is simply slow. If you still want Xft fonts you might try to disable
296     antialiasing (by appending ":antialias=false"), which saves lots of
297     memory and also speeds up rendering considerably.
298    
299     Rxvt-unicode doesn't seem to anti-alias its fonts, what is wrong?
300     Rxvt-unicode will use whatever you specify as a font. If it needs to
301     fall back to its default font search list it will prefer X11 core fonts,
302     because they are small and fast, and then use Xft fonts. It has
303     antialiasing disabled for most of them, because the author thinks they
304     look best that way.
305    
306     If you want antialiasing, you have to specify the fonts manually.
307    
308     What's with this bold/blink stuff?
309     If no bold colour is set via "colorBD:", bold will invert text using the
310     standard foreground colour.
311    
312     For the standard background colour, blinking will actually make the text
313 root 1.52 blink when compiled with "--enable-text-blink". Without
314     "--enable-text-blink", the blink attribute will be ignored.
315 root 1.42
316     On ANSI colours, bold/blink attributes are used to set high-intensity
317     foreground/background colors.
318    
319     color0-7 are the low-intensity colors.
320    
321     color8-15 are the corresponding high-intensity colors.
322    
323     I don't like the screen colors. How do I change them?
324     You can change the screen colors at run-time using ~/.Xdefaults
325     resources (or as long-options).
326    
327     Here are values that are supposed to resemble a VGA screen, including
328     the murky brown that passes for low-intensity yellow:
329    
330     URxvt.color0: #000000
331     URxvt.color1: #A80000
332     URxvt.color2: #00A800
333     URxvt.color3: #A8A800
334     URxvt.color4: #0000A8
335     URxvt.color5: #A800A8
336     URxvt.color6: #00A8A8
337     URxvt.color7: #A8A8A8
338    
339     URxvt.color8: #000054
340     URxvt.color9: #FF0054
341     URxvt.color10: #00FF54
342     URxvt.color11: #FFFF54
343     URxvt.color12: #0000FF
344     URxvt.color13: #FF00FF
345     URxvt.color14: #00FFFF
346     URxvt.color15: #FFFFFF
347    
348     And here is a more complete set of non-standard colors.
349    
350     URxvt.cursorColor: #dc74d1
351     URxvt.pointerColor: #dc74d1
352     URxvt.background: #0e0e0e
353     URxvt.foreground: #4ad5e1
354     URxvt.color0: #000000
355     URxvt.color8: #8b8f93
356     URxvt.color1: #dc74d1
357     URxvt.color9: #dc74d1
358     URxvt.color2: #0eb8c7
359     URxvt.color10: #0eb8c7
360     URxvt.color3: #dfe37e
361     URxvt.color11: #dfe37e
362     URxvt.color5: #9e88f0
363     URxvt.color13: #9e88f0
364     URxvt.color6: #73f7ff
365     URxvt.color14: #73f7ff
366     URxvt.color7: #e1dddd
367     URxvt.color15: #e1dddd
368    
369     They have been described (not by me) as "pretty girly".
370    
371     Why do some characters look so much different than others?
372     See next entry.
373    
374     How does rxvt-unicode choose fonts?
375     Most fonts do not contain the full range of Unicode, which is fine.
376     Chances are that the font you (or the admin/package maintainer of your
377     system/os) have specified does not cover all the characters you want to
378     display.
379    
380     rxvt-unicode makes a best-effort try at finding a replacement font.
381     Often the result is fine, but sometimes the chosen font looks
382     bad/ugly/wrong. Some fonts have totally strange characters that don't
383     resemble the correct glyph at all, and rxvt-unicode lacks the artificial
384     intelligence to detect that a specific glyph is wrong: it has to believe
385     the font that the characters it claims to contain indeed look correct.
386    
387     In that case, select a font of your taste and add it to the font list,
388     e.g.:
389    
390     urxvt -fn basefont,font2,font3...
391    
392     When rxvt-unicode sees a character, it will first look at the base font.
393     If the base font does not contain the character, it will go to the next
394     font, and so on. Specifying your own fonts will also speed up this
395     search and use less resources within rxvt-unicode and the X-server.
396    
397     The only limitation is that none of the fonts may be larger than the
398     base font, as the base font defines the terminal character cell size,
399     which must be the same due to the way terminals work.
400    
401     Why do some chinese characters look so different than others?
402     This is because there is a difference between script and language --
403     rxvt-unicode does not know which language the text that is output is, as
404     it only knows the unicode character codes. If rxvt-unicode first sees a
405     japanese/chinese character, it might choose a japanese font for display.
406     Subsequent japanese characters will use that font. Now, many chinese
407     characters aren't represented in japanese fonts, so when the first
408     non-japanese character comes up, rxvt-unicode will look for a chinese
409     font -- unfortunately at this point, it will still use the japanese font
410     for chinese characters that are also in the japanese font.
411    
412     The workaround is easy: just tag a chinese font at the end of your font
413     list (see the previous question). The key is to view the font list as a
414     preference list: If you expect more japanese, list a japanese font
415     first. If you expect more chinese, put a chinese font first.
416    
417     In the future it might be possible to switch language preferences at
418     runtime (the internal data structure has no problem with using different
419     fonts for the same character at the same time, but no interface for this
420     has been designed yet).
421    
422     Until then, you might get away with switching fonts at runtime (see "Can
423     I switch the fonts at runtime?" later in this document).
424    
425 root 1.50 How can I make mplayer display video correctly?
426     We are working on it, in the meantime, as a workaround, use something
427     like:
428    
429     urxvt -b 600 -geometry 20x1 -e sh -c 'mplayer -wid $WINDOWID file...'
430    
431 root 1.42 Keyboard, Mouse & User Interaction
432     The new selection selects pieces that are too big, how can I select single words?
433     If you want to select e.g. alphanumeric words, you can use the following
434     setting:
435    
436     URxvt.selection.pattern-0: ([[:word:]]+)
437    
438     If you click more than twice, the selection will be extended more and
439     more.
440    
441     To get a selection that is very similar to the old code, try this
442     pattern:
443    
444     URxvt.selection.pattern-0: ([^"&'()*,;<=>?@[\\\\]^`{|})]+)
445    
446 root 1.53 Please also note that the *LeftClick Shift-LeftClick* combination also
447 root 1.42 selects words like the old code.
448    
449     I don't like the new selection/popups/hotkeys/perl, how do I change/disable it?
450     You can disable the perl extension completely by setting the
451     perl-ext-common resource to the empty string, which also keeps
452     rxvt-unicode from initialising perl, saving memory.
453    
454     If you only want to disable specific features, you first have to
455     identify which perl extension is responsible. For this, read the section
456     PREPACKAGED EXTENSIONS in the urxvtperl(3) manpage. For example, to
457     disable the selection-popup and option-popup, specify this
458     perl-ext-common resource:
459    
460     URxvt.perl-ext-common: default,-selection-popup,-option-popup
461    
462     This will keep the default extensions, but disable the two popup
463     extensions. Some extensions can also be configured, for example,
464     scrollback search mode is triggered by M-s. You can move it to any other
465     combination either by setting the searchable-scrollback resource:
466    
467     URxvt.searchable-scrollback: CM-s
468    
469     The cursor moves when selecting text in the current input line, how do I switch this off?
470     See next entry.
471    
472     During rlogin/ssh/telnet/etc. sessions, clicking near the cursor outputs strange escape sequences, how do I fix this?
473     These are caused by the "readline" perl extension. Under normal
474     circumstances, it will move your cursor around when you click into the
475     line that contains it. It tries hard not to do this at the wrong moment,
476     but when running a program that doesn't parse cursor movements or in
477     some cases during rlogin sessions, it fails to detect this properly.
478    
479 root 1.43 You can permanently switch this feature off by disabling the "readline"
480 root 1.42 extension:
481    
482     URxvt.perl-ext-common: default,-readline
483    
484     My numerical keypad acts weird and generates differing output?
485     Some Debian GNUL/Linux users seem to have this problem, although no
486     specific details were reported so far. It is possible that this is
487 root 1.43 caused by the wrong "TERM" setting, although the details of whether and
488 root 1.42 how this can happen are unknown, as "TERM=rxvt" should offer a
489     compatible keymap. See the answer to the previous question, and please
490     report if that helped.
491    
492     My Compose (Multi_key) key is no longer working.
493     The most common causes for this are that either your locale is not set
494     correctly, or you specified a preeditStyle that is not supported by your
495     input method. For example, if you specified OverTheSpot and your input
496     method (e.g. the default input method handling Compose keys) does not
497     support this (for instance because it is not visual), then rxvt-unicode
498     will continue without an input method.
499    
500     In this case either do not specify a preeditStyle or specify more than
501     one pre-edit style, such as OverTheSpot,Root,None.
502    
503     I cannot type "Ctrl-Shift-2" to get an ASCII NUL character due to ISO 14755
504     Either try "Ctrl-2" alone (it often is mapped to ASCII NUL even on
505     international keyboards) or simply use ISO 14755 support to your
506     advantage, typing <Ctrl-Shift-0> to get a ASCII NUL. This works for
507     other codes, too, such as "Ctrl-Shift-1-d" to type the default telnet
508     escape character and so on.
509    
510     Mouse cut/paste suddenly no longer works.
511     Make sure that mouse reporting is actually turned off since killing some
512     editors prematurely may leave the mouse in mouse report mode. I've heard
513     that tcsh may use mouse reporting unless it otherwise specified. A quick
514     check is to see if cut/paste works when the Alt or Shift keys are
515     depressed.
516    
517     What's with the strange Backspace/Delete key behaviour?
518 root 1.43 Assuming that the physical Backspace key corresponds to the Backspace
519 root 1.42 keysym (not likely for Linux ... see the following question) there are
520     two standard values that can be used for Backspace: "^H" and "^?".
521    
522     Historically, either value is correct, but rxvt-unicode adopts the
523 root 1.47 debian policy of using "^?" when unsure, because it's the one and only
524 root 1.42 correct choice :).
525    
526     Rxvt-unicode tries to inherit the current stty settings and uses the
527     value of `erase' to guess the value for backspace. If rxvt-unicode
528     wasn't started from a terminal (say, from a menu or by remote shell),
529     then the system value of `erase', which corresponds to CERASE in
530     <termios.h>, will be used (which may not be the same as your stty
531     setting).
532    
533     For starting a new rxvt-unicode:
534    
535     # use Backspace = ^H
536     $ stty erase ^H
537     $ urxvt
538    
539     # use Backspace = ^?
540     $ stty erase ^?
541     $ urxvt
542    
543     Toggle with "ESC [ 36 h" / "ESC [ 36 l".
544    
545     For an existing rxvt-unicode:
546    
547     # use Backspace = ^H
548     $ stty erase ^H
549     $ echo -n "^[[36h"
550    
551     # use Backspace = ^?
552     $ stty erase ^?
553     $ echo -n "^[[36l"
554    
555     This helps satisfy some of the Backspace discrepancies that occur, but
556     if you use Backspace = "^H", make sure that the termcap/terminfo value
557     properly reflects that.
558    
559     The Delete key is a another casualty of the ill-defined Backspace
560     problem. To avoid confusion between the Backspace and Delete keys, the
561     Delete key has been assigned an escape sequence to match the vt100 for
562     Execute ("ESC [ 3 ~") and is in the supplied termcap/terminfo.
563    
564     Some other Backspace problems:
565    
566     some editors use termcap/terminfo, some editors (vim I'm told) expect
567     Backspace = ^H, GNU Emacs (and Emacs-like editors) use ^H for help.
568    
569     Perhaps someday this will all be resolved in a consistent manner.
570    
571     I don't like the key-bindings. How do I change them?
572     There are some compile-time selections available via configure. Unless
573     you have run "configure" with the "--disable-resources" option you can
574     use the `keysym' resource to alter the keystrings associated with
575     keysyms.
576    
577     Here's an example for a URxvt session started using "urxvt -name URxvt"
578    
579     URxvt.keysym.Home: \033[1~
580     URxvt.keysym.End: \033[4~
581     URxvt.keysym.C-apostrophe: \033<C-'>
582     URxvt.keysym.C-slash: \033<C-/>
583     URxvt.keysym.C-semicolon: \033<C-;>
584     URxvt.keysym.C-grave: \033<C-`>
585     URxvt.keysym.C-comma: \033<C-,>
586     URxvt.keysym.C-period: \033<C-.>
587     URxvt.keysym.C-0x60: \033<C-`>
588     URxvt.keysym.C-Tab: \033<C-Tab>
589     URxvt.keysym.C-Return: \033<C-Return>
590     URxvt.keysym.S-Return: \033<S-Return>
591     URxvt.keysym.S-space: \033<S-Space>
592     URxvt.keysym.M-Up: \033<M-Up>
593     URxvt.keysym.M-Down: \033<M-Down>
594     URxvt.keysym.M-Left: \033<M-Left>
595     URxvt.keysym.M-Right: \033<M-Right>
596     URxvt.keysym.M-C-0: list \033<M-C- 0123456789 >
597     URxvt.keysym.M-C-a: list \033<M-C- abcdefghijklmnopqrstuvwxyz >
598     URxvt.keysym.F12: command:\033]701;zh_CN.GBK\007
599    
600     See some more examples in the documentation for the keysym resource.
601    
602     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
603     KP_Insert == Insert
604     F22 == Print
605     F27 == Home
606     F29 == Prior
607     F33 == End
608     F35 == Next
609    
610     Rather than have rxvt-unicode try to accommodate all the various
611     possible keyboard mappings, it is better to use `xmodmap' to remap the
612     keys as required for your particular machine.
613    
614     Terminal Configuration
615     Can I see a typical configuration?
616     The default configuration tries to be xterm-like, which I don't like
617     that much, but it's least surprise to regular users.
618    
619     As a rxvt or rxvt-unicode user, you are practically supposed to invest
620     time into customising your terminal. To get you started, here is the
621     author's .Xdefaults entries, with comments on what they do. It's
622     certainly not *typical*, but what's typical...
623    
624     URxvt.cutchars: "()*,<>[]{}|'
625     URxvt.print-pipe: cat >/tmp/xxx
626    
627     These are just for testing stuff.
628    
629     URxvt.imLocale: ja_JP.UTF-8
630     URxvt.preeditType: OnTheSpot,None
631    
632     This tells rxvt-unicode to use a special locale when communicating with
633     the X Input Method, and also tells it to only use the OnTheSpot pre-edit
634     type, which requires the "xim-onthespot" perl extension but rewards me
635     with correct-looking fonts.
636    
637     URxvt.perl-lib: /root/lib/urxvt
638     URxvt.perl-ext-common: default,selection-autotransform,selection-pastebin,xim-onthespot,remote-clipboard
639     URxvt.selection.pattern-0: ( at .*? line \\d+)
640     URxvt.selection.pattern-1: ^(/[^:]+):\
641     URxvt.selection-autotransform.0: s/^([^:[:space:]]+):(\\d+):?$/:e \\Q$1\\E\\x0d:$2\\x0d/
642     URxvt.selection-autotransform.1: s/^ at (.*?) line (\\d+)$/:e \\Q$1\\E\\x0d:$2\\x0d/
643    
644     This is my perl configuration. The first two set the perl library
645     directory and also tells urxvt to use a large number of extensions. I
646     develop for myself mostly, so I actually use most of the extensions I
647     write.
648    
649     The selection stuff mainly makes the selection perl-error-message aware
650 root 1.43 and tells it to convert perl error messages into vi-commands to load the
651 root 1.42 relevant file and go tot he error line number.
652    
653     URxvt.scrollstyle: plain
654     URxvt.secondaryScroll: true
655    
656     As the documentation says: plain is the preferred scrollbar for the
657 root 1.43 author. The "secondaryScroll" configures urxvt to scroll in full-screen
658     apps, like screen, so lines scrolled out of screen end up in urxvt's
659 root 1.42 scrollback buffer.
660    
661     URxvt.background: #000000
662     URxvt.foreground: gray90
663     URxvt.color7: gray90
664     URxvt.colorBD: #ffffff
665     URxvt.cursorColor: #e0e080
666     URxvt.throughColor: #8080f0
667     URxvt.highlightColor: #f0f0f0
668    
669     Some colours. Not sure which ones are being used or even non-defaults,
670     but these are in my .Xdefaults. Most notably, they set
671     foreground/background to light gray/black, and also make sure that the
672     colour 7 matches the default foreground colour.
673    
674     URxvt.underlineColor: yellow
675    
676     Another colour, makes underline lines look different. Sometimes hurts,
677     but is mostly a nice effect.
678    
679     URxvt.geometry: 154x36
680     URxvt.loginShell: false
681     URxvt.meta: ignore
682     URxvt.utmpInhibit: true
683    
684     Uh, well, should be mostly self-explanatory. By specifying some defaults
685     manually, I can quickly switch them for testing.
686    
687     URxvt.saveLines: 8192
688    
689     A large scrollback buffer is essential. Really.
690    
691     URxvt.mapAlert: true
692    
693     The only case I use it is for my IRC window, which I like to keep
694     iconified till people msg me (which beeps).
695    
696     URxvt.visualBell: true
697    
698     The audible bell is often annoying, especially when in a crowd.
699    
700     URxvt.insecure: true
701    
702     Please don't hack my mutt! Ooops...
703    
704     URxvt.pastableTabs: false
705    
706     I once thought this is a great idea.
707    
708     urxvt.font: 9x15bold,\
709     -misc-fixed-bold-r-normal--15-140-75-75-c-90-iso10646-1,\
710     -misc-fixed-medium-r-normal--15-140-75-75-c-90-iso10646-1, \
711     [codeset=JISX0208]xft:Kochi Gothic, \
712     xft:Bitstream Vera Sans Mono:autohint=true, \
713     xft:Code2000:antialias=false
714     urxvt.boldFont: -xos4-terminus-bold-r-normal--14-140-72-72-c-80-iso8859-15
715     urxvt.italicFont: xft:Bitstream Vera Sans Mono:italic:autohint=true
716     urxvt.boldItalicFont: xft:Bitstream Vera Sans Mono:bold:italic:autohint=true
717    
718     I wrote rxvt-unicode to be able to specify fonts exactly. So don't be
719 root 1.43 overwhelmed. A special note: the "9x15bold" mentioned above is actually
720 root 1.42 the version from XFree-3.3, as XFree-4 replaced it by a totally
721     different font (different glyphs for ";" and many other harmless
722     characters), while the second font is actually the "9x15bold" from
723     XFree4/XOrg. The bold version has less chars than the medium version, so
724 root 1.43 I use it for rare characters, too. When editing sources with vim, I use
725 root 1.42 italic for comments and other stuff, which looks quite good with
726     Bitstream Vera anti-aliased.
727    
728     Terminus is a quite bad font (many very wrong glyphs), but for most of
729     my purposes, it works, and gives a different look, as my normal
730     (Non-bold) font is already bold, and I want to see a difference between
731     bold and normal fonts.
732    
733     Please note that I used the "urxvt" instance name and not the "URxvt"
734     class name. Thats because I use different configs for different
735     purposes, for example, my IRC window is started with "-name IRC", and
736     uses these defaults:
737    
738     IRC*title: IRC
739     IRC*geometry: 87x12+535+542
740     IRC*saveLines: 0
741     IRC*mapAlert: true
742     IRC*font: suxuseuro
743     IRC*boldFont: suxuseuro
744     IRC*colorBD: white
745     IRC*keysym.M-C-1: command:\033]710;suxuseuro\007\033]711;suxuseuro\007
746     IRC*keysym.M-C-2: command:\033]710;9x15bold\007\033]711;9x15bold\007
747    
748     "Alt-Shift-1" and "Alt-Shift-2" switch between two different font sizes.
749     "suxuseuro" allows me to keep an eye (and actually read) stuff while
750     keeping a very small window. If somebody pastes something complicated
751     (e.g. japanese), I temporarily switch to a larger font.
752    
753     The above is all in my ".Xdefaults" (I don't use ".Xresources" nor
754     "xrdb"). I also have some resources in a separate ".Xdefaults-hostname"
755     file for different hosts, for example, on ym main desktop, I use:
756    
757     URxvt.keysym.C-M-q: command:\033[3;5;5t
758     URxvt.keysym.C-M-y: command:\033[3;5;606t
759     URxvt.keysym.C-M-e: command:\033[3;1605;5t
760     URxvt.keysym.C-M-c: command:\033[3;1605;606t
761     URxvt.keysym.C-M-p: perl:test
762    
763     The first for keysym definitions allow me to quickly bring some windows
764     in the layout I like most. Ion users might start laughing but will stop
765     immediately when I tell them that I use my own Fvwm2 module for much the
766     same effect as Ion provides, and I only very rarely use the above key
767     combinations :->
768    
769     Why doesn't rxvt-unicode read my resources?
770     Well, why, indeed? It does, in a way very similar to other X
771     applications. Most importantly, this means that if you or your OS loads
772     resources into the X display (the right way to do it), rxvt-unicode will
773     ignore any resource files in your home directory. It will only read
774     $HOME/.Xdefaults when no resources are attached to the display.
775    
776     If you have or use an $HOME/.Xresources file, chances are that resources
777     are loaded into your X-server. In this case, you have to re-login after
778     every change (or run xrdb -merge $HOME/.Xresources).
779    
780     Also consider the form resources have to use:
781    
782     URxvt.resource: value
783    
784     If you want to use another form (there are lots of different ways of
785 root 1.43 specifying resources), make sure you understand whether and why it
786     works. If unsure, use the form above.
787 root 1.42
788     When I log-in to another system it tells me about missing terminfo data?
789     The terminal description used by rxvt-unicode is not as widely available
790     as that for xterm, or even rxvt (for which the same problem often
791     arises).
792    
793     The correct solution for this problem is to install the terminfo, this
794 root 1.44 can be done like this (with ncurses' infocmp and works as user and
795     admin):
796 root 1.42
797     REMOTE=remotesystem.domain
798 root 1.44 infocmp rxvt-unicode | ssh $REMOTE "mkdir -p .terminfo && cat >/tmp/ti && tic /tmp/ti"
799 root 1.42
800     ... or by installing rxvt-unicode normally on the remote system,
801    
802 root 1.44 One some systems you might need to set $TERMINFO to the full path of
803     $HOME/.terminfo for this to work.
804    
805 root 1.42 If you cannot or do not want to do this, then you can simply set
806     "TERM=rxvt" or even "TERM=xterm", and live with the small number of
807     problems arising, which includes wrong keymapping, less and different
808     colours and some refresh errors in fullscreen applications. It's a nice
809     quick-and-dirty workaround for rare cases, though.
810    
811     If you always want to do this (and are fine with the consequences) you
812     can either recompile rxvt-unicode with the desired TERM value or use a
813     resource to set it:
814    
815     URxvt.termName: rxvt
816    
817     If you don't plan to use rxvt (quite common...) you could also replace
818     the rxvt terminfo file with the rxvt-unicode one and use "TERM=rxvt".
819    
820     "tic" outputs some error when compiling the terminfo entry.
821     Most likely it's the empty definition for "enacs=". Just replace it by
822     "enacs=\E[0@" and try again.
823    
824     "bash"'s readline does not work correctly under urxvt.
825     See next entry.
826    
827     I need a termcap file entry.
828     One reason you might want this is that some distributions or operating
829     systems still compile some programs using the long-obsoleted termcap
830     library (Fedora Core's bash is one example) and rely on a termcap entry
831     for "rxvt-unicode".
832    
833 root 1.43 You could use rxvt's termcap entry with reasonable results in many
834     cases. You can also create a termcap entry by using terminfo's infocmp
835     program like this:
836 root 1.42
837     infocmp -C rxvt-unicode
838    
839 root 1.55 Or you could use the termcap entry in doc/etc/rxvt-unicode.termcap,
840     generated by the command above.
841 root 1.42
842     Why does "ls" no longer have coloured output?
843     The "ls" in the GNU coreutils unfortunately doesn't use terminfo to
844 root 1.43 decide whether a terminal has colour, but uses its own configuration
845 root 1.42 file. Needless to say, "rxvt-unicode" is not in its default file (among
846     with most other terminals supporting colour). Either add:
847    
848     TERM rxvt-unicode
849    
850     to "/etc/DIR_COLORS" or simply add:
851    
852     alias ls='ls --color=auto'
853    
854     to your ".profile" or ".bashrc".
855    
856     Why doesn't vim/emacs etc. use the 88 colour mode?
857     See next entry.
858    
859     Why doesn't vim/emacs etc. make use of italic?
860     See next entry.
861    
862     Why are the secondary screen-related options not working properly?
863     Make sure you are using "TERM=rxvt-unicode". Some pre-packaged
864     distributions (most notably Debian GNU/Linux) break rxvt-unicode by
865     setting "TERM" to "rxvt", which doesn't have these extra features.
866     Unfortunately, some of these (most notably, again, Debian GNU/Linux)
867     furthermore fail to even install the "rxvt-unicode" terminfo file, so
868     you will need to install it on your own (See the question When I log-in
869     to another system it tells me about missing terminfo data? on how to do
870     this).
871    
872     Encoding / Locale / Input Method Issues
873     Rxvt-unicode does not seem to understand the selected encoding?
874     See next entry.
875    
876     Unicode does not seem to work?
877     If you encounter strange problems like typing an accented character but
878     getting two unrelated other characters or similar, or if program output
879     is subtly garbled, then you should check your locale settings.
880    
881     Rxvt-unicode must be started with the same "LC_CTYPE" setting as the
882 root 1.46 programs running in it. Often rxvt-unicode is started in the "C" locale,
883     while the login script running within the rxvt-unicode window changes
884     the locale to something else, e.g. "en_GB.UTF-8". Needless to say, this
885     is not going to work, and is the most common cause for problems.
886 root 1.42
887     The best thing is to fix your startup environment, as you will likely
888     run into other problems. If nothing works you can try this in your
889     .profile.
890    
891 root 1.46 printf '\33]701;%s\007' "$LC_CTYPE" # $LANG or $LC_ALL are worth a try, too
892 root 1.42
893     If this doesn't work, then maybe you use a "LC_CTYPE" specification not
894     supported on your systems. Some systems have a "locale" command which
895     displays this (also, "perl -e0" can be used to check locale settings, as
896     it will complain loudly if it cannot set the locale). If it displays
897     something like:
898    
899     locale: Cannot set LC_CTYPE to default locale: ...
900    
901     Then the locale you specified is not supported on your system.
902    
903     If nothing works and you are sure that everything is set correctly then
904     you will need to remember a little known fact: Some programs just don't
905     support locales :(
906    
907     How does rxvt-unicode determine the encoding to use?
908     See next entry.
909    
910     Is there an option to switch encodings?
911     Unlike some other terminals, rxvt-unicode has no encoding switch, and no
912     specific "utf-8" mode, such as xterm. In fact, it doesn't even know
913     about UTF-8 or any other encodings with respect to terminal I/O.
914    
915     The reasons is that there exists a perfectly fine mechanism for
916     selecting the encoding, doing I/O and (most important) communicating
917     this to all applications so everybody agrees on character properties
918     such as width and code number. This mechanism is the *locale*.
919     Applications not using that info will have problems (for example,
920     "xterm" gets the width of characters wrong as it uses its own,
921     locale-independent table under all locales).
922    
923     Rxvt-unicode uses the "LC_CTYPE" locale category to select encoding. All
924     programs doing the same (that is, most) will automatically agree in the
925     interpretation of characters.
926    
927     Unfortunately, there is no system-independent way to select locales, nor
928     is there a standard on how locale specifiers will look like.
929    
930     On most systems, the content of the "LC_CTYPE" environment variable
931     contains an arbitrary string which corresponds to an already-installed
932     locale. Common names for locales are "en_US.UTF-8", "de_DE.ISO-8859-15",
933     "ja_JP.EUC-JP", i.e. "language_country.encoding", but other forms (i.e.
934     "de" or "german") are also common.
935    
936     Rxvt-unicode ignores all other locale categories, and except for the
937     encoding, ignores country or language-specific settings, i.e.
938     "de_DE.UTF-8" and "ja_JP.UTF-8" are the normally same to rxvt-unicode.
939    
940     If you want to use a specific encoding you have to make sure you start
941     rxvt-unicode with the correct "LC_CTYPE" category.
942    
943     Can I switch locales at runtime?
944     Yes, using an escape sequence. Try something like this, which sets
945     rxvt-unicode's idea of "LC_CTYPE".
946    
947     printf '\33]701;%s\007' ja_JP.SJIS
948    
949     See also the previous answer.
950    
951     Sometimes this capability is rather handy when you want to work in one
952     locale (e.g. "de_DE.UTF-8") but some programs don't support it (e.g.
953     UTF-8). For example, I use this script to start "xjdic", which first
954     switches to a locale supported by xjdic and back later:
955    
956     printf '\33]701;%s\007' ja_JP.SJIS
957     xjdic -js
958     printf '\33]701;%s\007' de_DE.UTF-8
959    
960     You can also use xterm's "luit" program, which usually works fine,
961     except for some locales where character width differs between program-
962     and rxvt-unicode-locales.
963    
964     I have problems getting my input method working.
965     Try a search engine, as this is slightly different for every input
966     method server.
967    
968     Here is a checklist:
969    
970     - Make sure your locale *and* the imLocale are supported on your OS.
971     Try "locale -a" or check the documentation for your OS.
972    
973     - Make sure your locale or imLocale matches a locale supported by your
974     XIM.
975     For example, kinput2 does not support UTF-8 locales, you should use
976     "ja_JP.EUC-JP" or equivalent.
977    
978     - Make sure your XIM server is actually running.
979     - Make sure the "XMODIFIERS" environment variable is set correctly when
980     *starting* rxvt-unicode.
981     When you want to use e.g. kinput2, it must be set to "@im=kinput2".
982 root 1.43 For scim, use "@im=SCIM". You can see what input method servers are
983 root 1.42 running with this command:
984    
985     xprop -root XIM_SERVERS
986    
987 root 1.54
988 root 1.42
989     My input method wants <some encoding> but I want UTF-8, what can I do?
990     You can specify separate locales for the input method and the rest of
991     the terminal, using the resource "imlocale":
992    
993     URxvt.imlocale: ja_JP.EUC-JP
994    
995     Now you can start your terminal with "LC_CTYPE=ja_JP.UTF-8" and still
996     use your input method. Please note, however, that, depending on your
997     Xlib version, you may not be able to input characters outside "EUC-JP"
998     in a normal way then, as your input method limits you.
999    
1000     Rxvt-unicode crashes when the X Input Method changes or exits.
1001     Unfortunately, this is unavoidable, as the XIM protocol is racy by
1002     design. Applications can avoid some crashes at the expense of memory
1003     leaks, and Input Methods can avoid some crashes by careful ordering at
1004     exit time. kinput2 (and derived input methods) generally succeeds, while
1005     SCIM (or similar input methods) fails. In the end, however, crashes
1006     cannot be completely avoided even if both sides cooperate.
1007    
1008     So the only workaround is not to kill your Input Method Servers.
1009    
1010     Operating Systems / Package Maintaining
1011     I am using Debian GNU/Linux and have a problem...
1012     The Debian GNU/Linux package of rxvt-unicode in sarge contains large
1013     patches that considerably change the behaviour of rxvt-unicode (but
1014     unfortunately this notice has been removed). Before reporting a bug to
1015     the original rxvt-unicode author please download and install the genuine
1016     version (<http://software.schmorp.de#rxvt-unicode>) and try to reproduce
1017     the problem. If you cannot, chances are that the problems are specific
1018     to Debian GNU/Linux, in which case it should be reported via the Debian
1019     Bug Tracking System (use "reportbug" to report the bug).
1020    
1021     For other problems that also affect the Debian package, you can and
1022     probably should use the Debian BTS, too, because, after all, it's also a
1023     bug in the Debian version and it serves as a reminder for other users
1024     that might encounter the same issue.
1025    
1026     I am maintaining rxvt-unicode for distribution/OS XXX, any recommendation?
1027     You should build one binary with the default options. configure now
1028     enables most useful options, and the trend goes to making them
1029 root 1.43 runtime-switchable, too, so there is usually no drawback to enabling
1030 root 1.42 them, except higher disk and possibly memory usage. The perl interpreter
1031     should be enabled, as important functionality (menus, selection, likely
1032     more in the future) depends on it.
1033    
1034     You should not overwrite the "perl-ext-common" snd "perl-ext" resources
1035     system-wide (except maybe with "defaults"). This will result in useful
1036     behaviour. If your distribution aims at low memory, add an empty
1037     "perl-ext-common" resource to the app-defaults file. This will keep the
1038     perl interpreter disabled until the user enables it.
1039    
1040     If you can/want build more binaries, I recommend building a minimal one
1041     with "--disable-everything" (very useful) and a maximal one with
1042     "--enable-everything" (less useful, it will be very big due to a lot of
1043     encodings built-in that increase download times and are rarely used).
1044    
1045     I need to make it setuid/setgid to support utmp/ptys on my OS, is this safe?
1046     It should be, starting with release 7.1. You are encouraged to properly
1047     install urxvt with privileges necessary for your OS now.
1048    
1049     When rxvt-unicode detects that it runs setuid or setgid, it will fork
1050     into a helper process for privileged operations (pty handling on some
1051     systems, utmp/wtmp/lastlog handling on others) and drop privileges
1052     immediately. This is much safer than most other terminals that keep
1053     privileges while running (but is more relevant to urxvt, as it contains
1054     things as perl interpreters, which might be "helpful" to attackers).
1055    
1056     This forking is done as the very first within main(), which is very
1057     early and reduces possible bugs to initialisation code run before
1058     main(), or things like the dynamic loader of your system, which should
1059     result in very little risk.
1060    
1061     I am on FreeBSD and rxvt-unicode does not seem to work at all.
1062     Rxvt-unicode requires the symbol "__STDC_ISO_10646__" to be defined in
1063     your compile environment, or an implementation that implements it,
1064 root 1.43 whether it defines the symbol or not. "__STDC_ISO_10646__" requires that
1065 root 1.42 wchar_t is represented as unicode.
1066    
1067 root 1.43 As you might have guessed, FreeBSD does neither define this symbol nor
1068 root 1.42 does it support it. Instead, it uses its own internal representation of
1069     wchar_t. This is, of course, completely fine with respect to standards.
1070    
1071     However, that means rxvt-unicode only works in "POSIX", "ISO-8859-1" and
1072 root 1.55 "UTF-8" locales under FreeBSD (which all use Unicode as wchar_t).
1073 root 1.42
1074     "__STDC_ISO_10646__" is the only sane way to support multi-language apps
1075     in an OS, as using a locale-dependent (and non-standardized)
1076     representation of wchar_t makes it impossible to convert between wchar_t
1077     (as used by X11 and your applications) and any other encoding without
1078     implementing OS-specific-wrappers for each and every locale. There
1079     simply are no APIs to convert wchar_t into anything except the current
1080     locale encoding.
1081    
1082     Some applications (such as the formidable mlterm) work around this by
1083     carrying their own replacement functions for character set handling with
1084     them, and either implementing OS-dependent hacks or doing multiple
1085     conversions (which is slow and unreliable in case the OS implements
1086     encodings slightly different than the terminal emulator).
1087    
1088     The rxvt-unicode author insists that the right way to fix this is in the
1089     system libraries once and for all, instead of forcing every app to carry
1090     complete replacements for them :)
1091    
1092     How can I use rxvt-unicode under cygwin?
1093     rxvt-unicode should compile and run out of the box on cygwin, using the
1094     X11 libraries that come with cygwin. libW11 emulation is no longer
1095     supported (and makes no sense, either, as it only supported a single
1096     font). I recommend starting the X-server in "-multiwindow" or
1097     "-rootless" mode instead, which will result in similar look&feel as the
1098     old libW11 emulation.
1099    
1100     At the time of this writing, cygwin didn't seem to support any
1101     multi-byte encodings (you might try "LC_CTYPE=C-UTF-8"), so you are
1102     likely limited to 8-bit encodings.
1103    
1104 root 1.49 Character widths are not correct.
1105     urxvt uses the system wcwidth function to know the information about the
1106     width of characters, so on systems with incorrect locale data you will
1107     likely get bad results. Two notorious examples are Solaris 9, where
1108     single-width characters like U+2514 are reported as double-width, and
1109     Darwin 8, where combining chars are reported having width 1.
1110    
1111     The solution is to upgrade your system or switch to a better one. A
1112     possibly working workaround is to use a wcwidth implementation like
1113    
1114     http://www.cl.cam.ac.uk/~mgk25/ucs/wcwidth.c
1115