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Revision: 1.72
Committed: Sat May 14 08:28:25 2016 UTC (8 years ago) by root
Branch: MAIN
CVS Tags: rxvt-unicode-rel-9_22
Changes since 1.71: +7 -4 lines
Log Message:
9.22-maybe

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 root 1.70 There are two big problems with Gentoo Linux: first, most if not all
10     Gentoo systems are completely broken (missing or mismatched header
11     files, broken compiler etc. are just the tip of the iceberg); secondly,
12     it should be called Gentoo GNU/Linux.
13 root 1.56
14     For these reasons, it is impossible to support rxvt-unicode on Gentoo.
15     Problems appearing on Gentoo systems will usually simply be ignored
16     unless they can be reproduced on non-Gentoo systems.
17    
18 root 1.42 Does it support tabs, can I have a tabbed rxvt-unicode?
19     Beginning with version 7.3, there is a perl extension that implements a
20     simple tabbed terminal. It is installed by default, so any of these
21     should give you tabs:
22    
23     urxvt -pe tabbed
24    
25     URxvt.perl-ext-common: default,tabbed
26    
27     It will also work fine with tabbing functionality of many window
28     managers or similar tabbing programs, and its embedding-features allow
29     it to be embedded into other programs, as witnessed by doc/rxvt-tabbed
30     or the upcoming "Gtk2::URxvt" perl module, which features a tabbed urxvt
31     (murxvt) terminal as an example embedding application.
32    
33     How do I know which rxvt-unicode version I'm using?
34     The version number is displayed with the usage (-h). Also the escape
35     sequence "ESC [ 8 n" sets the window title to the version number. When
36     using the urxvtc client, the version displayed is that of the daemon.
37    
38     Rxvt-unicode uses gobs of memory, how can I reduce that?
39     Rxvt-unicode tries to obey the rule of not charging you for something
40     you don't use. One thing you should try is to configure out all settings
41     that you don't need, for example, Xft support is a resource hog by
42     design, when used. Compiling it out ensures that no Xft font will be
43     loaded accidentally when rxvt-unicode tries to find a font for your
44     characters.
45    
46     Also, many people (me included) like large windows and even larger
47     scrollback buffers: Without "--enable-unicode3", rxvt-unicode will use 6
48     bytes per screen cell. For a 160x?? window this amounts to almost a
49     kilobyte per line. A scrollback buffer of 10000 lines will then (if
50     full) use 10 Megabytes of memory. With "--enable-unicode3" it gets
51     worse, as rxvt-unicode then uses 8 bytes per screen cell.
52    
53     How can I start urxvtd in a race-free way?
54     Try "urxvtd -f -o", which tells urxvtd to open the display, create the
55     listening socket and then fork.
56    
57 root 1.45 How can I start urxvtd automatically when I run urxvtc?
58 root 1.42 If you want to start urxvtd automatically whenever you run urxvtc and
59     the daemon isn't running yet, use this script:
60    
61     #!/bin/sh
62     urxvtc "$@"
63     if [ $? -eq 2 ]; then
64     urxvtd -q -o -f
65     urxvtc "$@"
66     fi
67    
68     This tries to create a new terminal, and if fails with exit status 2,
69     meaning it couldn't connect to the daemon, it will start the daemon and
70     re-run the command. Subsequent invocations of the script will re-use the
71     existing daemon.
72    
73 sf-exg 1.59 How do I distinguish whether I'm running rxvt-unicode or a regular
74     xterm? I need this to decide about setting colours 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 sf-exg 1.59 variable to decide whether or not to use colour.
79 root 1.42
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 [ ${TERM:-foo} = xterm ]; then
94     stty -icanon -echo min 0 time 15 # see if enhanced rxvt or not
95 root 1.67 printf "\eZ"
96 root 1.42 read term_id
97     stty icanon echo
98     if [ ""${term_id} = '^[[?1;2C' -a ${DISPLAY:-foo} = foo ]; then
99 root 1.67 printf '\e[7n' # query the rxvt we are in for the DISPLAY string
100     read DISPLAY # set it in our local shell
101 root 1.42 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 root 1.62 in C that use gobs of memory, and certainly possible to write programs
163     in C++ that don't. C++ also often comes with large libraries, but this
164     is not necessarily the case with GCC. Here is what rxvt links against on
165     my system with a minimal config:
166 root 1.42
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 1.61 First of all, transparency isn't officially supported in rxvt-unicode,
186     so you are mostly on your own. Do not bug the author about it (but you
187     may bug everybody else). Also, if you can't get it working consider it a
188     rite of passage: ... and you 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 root 1.62 support, or you are unable to read. This method requires that the
200     background-setting program sets the _XROOTPMAP_ID or ESETROOT_PMAP_ID
201     property. Compatible programs are Esetroot, hsetroot and feh.
202 root 1.42
203     2. Use a simple pixmap and emulate pseudo-transparency. This enables you
204     to use effects other than tinting and shading: Just shade/tint/whatever
205     your picture with gimp or any other tool:
206    
207 root 1.50 convert wallpaper.jpg -blur 20x20 -modulate 30 background.jpg
208 root 1.51 urxvt -pixmap "background.jpg;:root"
209 root 1.42
210 root 1.66 That works. If you think it doesn't, you lack GDK-PixBuf support, or you
211     are unable to read.
212 root 1.42
213     3. Use an ARGB visual:
214    
215     urxvt -depth 32 -fg grey90 -bg rgba:0000/0000/4444/cccc
216    
217     This requires XFT support, and the support of your X-server. If that
218     doesn't work for you, blame Xorg and Keith Packard. ARGB visuals aren't
219     there yet, no matter what they claim. Rxvt-Unicode contains the
220 root 1.43 necessary bugfixes and workarounds for Xft and Xlib to make it work, but
221     that doesn't mean that your WM has the required kludges in place.
222 root 1.42
223     4. Use xcompmgr and let it do the job:
224    
225     xprop -frame -f _NET_WM_WINDOW_OPACITY 32c \
226     -set _NET_WM_WINDOW_OPACITY 0xc0000000
227    
228     Then click on a window you want to make transparent. Replace 0xc0000000
229     by other values to change the degree of opacity. If it doesn't work and
230     your server crashes, you got to keep the pieces.
231    
232     Why does rxvt-unicode sometimes leave pixel droppings?
233     Most fonts were not designed for terminal use, which means that
234     character size varies a lot. A font that is otherwise fine for terminal
235     use might contain some characters that are simply too wide. Rxvt-unicode
236     will avoid these characters. For characters that are just "a bit" too
237     wide a special "careful" rendering mode is used that redraws adjacent
238     characters.
239    
240     All of this requires that fonts do not lie about character sizes,
241     however: Xft fonts often draw glyphs larger than their acclaimed
242     bounding box, and rxvt-unicode has no way of detecting this (the correct
243     way is to ask for the character bounding box, which unfortunately is
244     wrong in these cases).
245    
246 root 1.43 It's not clear (to me at least), whether this is a bug in Xft, freetype,
247 root 1.42 or the respective font. If you encounter this problem you might try
248     using the "-lsp" option to give the font more height. If that doesn't
249     work, you might be forced to use a different font.
250    
251     All of this is not a problem when using X11 core fonts, as their
252     bounding box data is correct.
253    
254     How can I keep rxvt-unicode from using reverse video so much?
255     First of all, make sure you are running with the right terminal settings
256     ("TERM=rxvt-unicode"), which will get rid of most of these effects. Then
257     make sure you have specified colours for italic and bold, as otherwise
258     rxvt-unicode might use reverse video to simulate the effect:
259    
260     URxvt.colorBD: white
261     URxvt.colorIT: green
262    
263     Some programs assume totally weird colours (red instead of blue), how can I fix that?
264     For some unexplainable reason, some rare programs assume a very weird
265     colour palette when confronted with a terminal with more than the
266     standard 8 colours (rxvt-unicode supports 88). The right fix is, of
267     course, to fix these programs not to assume non-ISO colours without very
268     good reasons.
269    
270     In the meantime, you can either edit your "rxvt-unicode" terminfo
271     definition to only claim 8 colour support or use "TERM=rxvt", which will
272     fix colours but keep you from using other rxvt-unicode features.
273    
274     Can I switch the fonts at runtime?
275     Yes, using an escape sequence. Try something like this, which has the
276     same effect as using the "-fn" switch, and takes effect immediately:
277    
278     printf '\33]50;%s\007' "9x15bold,xft:Kochi Gothic"
279    
280     This is useful if you e.g. work primarily with japanese (and prefer a
281     japanese font), but you have to switch to chinese temporarily, where
282     japanese fonts would only be in your way.
283    
284     You can think of this as a kind of manual ISO-2022 switching.
285    
286     Why do italic characters look as if clipped?
287     Many fonts have difficulties with italic characters and hinting. For
288     example, the otherwise very nicely hinted font "xft:Bitstream Vera Sans
289     Mono" completely fails in its italic face. A workaround might be to
290     enable freetype autohinting, i.e. like this:
291    
292     URxvt.italicFont: xft:Bitstream Vera Sans Mono:italic:autohint=true
293     URxvt.boldItalicFont: xft:Bitstream Vera Sans Mono:bold:italic:autohint=true
294    
295     Can I speed up Xft rendering somehow?
296     Yes, the most obvious way to speed it up is to avoid Xft entirely, as it
297     is simply slow. If you still want Xft fonts you might try to disable
298     antialiasing (by appending ":antialias=false"), which saves lots of
299     memory and also speeds up rendering considerably.
300    
301     Rxvt-unicode doesn't seem to anti-alias its fonts, what is wrong?
302     Rxvt-unicode will use whatever you specify as a font. If it needs to
303     fall back to its default font search list it will prefer X11 core fonts,
304     because they are small and fast, and then use Xft fonts. It has
305     antialiasing disabled for most of them, because the author thinks they
306     look best that way.
307    
308     If you want antialiasing, you have to specify the fonts manually.
309    
310     What's with this bold/blink stuff?
311     If no bold colour is set via "colorBD:", bold will invert text using the
312     standard foreground colour.
313    
314     For the standard background colour, blinking will actually make the text
315 root 1.52 blink when compiled with "--enable-text-blink". Without
316     "--enable-text-blink", the blink attribute will be ignored.
317 root 1.42
318     On ANSI colours, bold/blink attributes are used to set high-intensity
319 sf-exg 1.59 foreground/background colours.
320 root 1.42
321 sf-exg 1.59 color0-7 are the low-intensity colours.
322 root 1.42
323 sf-exg 1.59 color8-15 are the corresponding high-intensity colours.
324 root 1.42
325 sf-exg 1.59 I don't like the screen colours. How do I change them?
326     You can change the screen colours at run-time using ~/.Xdefaults
327 root 1.42 resources (or as long-options).
328    
329     Here are values that are supposed to resemble a VGA screen, including
330     the murky brown that passes for low-intensity yellow:
331    
332     URxvt.color0: #000000
333     URxvt.color1: #A80000
334     URxvt.color2: #00A800
335     URxvt.color3: #A8A800
336     URxvt.color4: #0000A8
337     URxvt.color5: #A800A8
338     URxvt.color6: #00A8A8
339     URxvt.color7: #A8A8A8
340    
341     URxvt.color8: #000054
342     URxvt.color9: #FF0054
343     URxvt.color10: #00FF54
344     URxvt.color11: #FFFF54
345     URxvt.color12: #0000FF
346     URxvt.color13: #FF00FF
347     URxvt.color14: #00FFFF
348     URxvt.color15: #FFFFFF
349    
350 sf-exg 1.59 And here is a more complete set of non-standard colours.
351 root 1.42
352     URxvt.cursorColor: #dc74d1
353     URxvt.pointerColor: #dc74d1
354     URxvt.background: #0e0e0e
355     URxvt.foreground: #4ad5e1
356     URxvt.color0: #000000
357     URxvt.color8: #8b8f93
358     URxvt.color1: #dc74d1
359     URxvt.color9: #dc74d1
360     URxvt.color2: #0eb8c7
361     URxvt.color10: #0eb8c7
362     URxvt.color3: #dfe37e
363     URxvt.color11: #dfe37e
364     URxvt.color5: #9e88f0
365     URxvt.color13: #9e88f0
366     URxvt.color6: #73f7ff
367     URxvt.color14: #73f7ff
368     URxvt.color7: #e1dddd
369     URxvt.color15: #e1dddd
370    
371     They have been described (not by me) as "pretty girly".
372    
373     Why do some characters look so much different than others?
374     See next entry.
375    
376     How does rxvt-unicode choose fonts?
377     Most fonts do not contain the full range of Unicode, which is fine.
378     Chances are that the font you (or the admin/package maintainer of your
379     system/os) have specified does not cover all the characters you want to
380     display.
381    
382     rxvt-unicode makes a best-effort try at finding a replacement font.
383     Often the result is fine, but sometimes the chosen font looks
384     bad/ugly/wrong. Some fonts have totally strange characters that don't
385     resemble the correct glyph at all, and rxvt-unicode lacks the artificial
386     intelligence to detect that a specific glyph is wrong: it has to believe
387     the font that the characters it claims to contain indeed look correct.
388    
389     In that case, select a font of your taste and add it to the font list,
390     e.g.:
391    
392     urxvt -fn basefont,font2,font3...
393    
394     When rxvt-unicode sees a character, it will first look at the base font.
395     If the base font does not contain the character, it will go to the next
396     font, and so on. Specifying your own fonts will also speed up this
397     search and use less resources within rxvt-unicode and the X-server.
398    
399     The only limitation is that none of the fonts may be larger than the
400     base font, as the base font defines the terminal character cell size,
401     which must be the same due to the way terminals work.
402    
403     Why do some chinese characters look so different than others?
404     This is because there is a difference between script and language --
405     rxvt-unicode does not know which language the text that is output is, as
406     it only knows the unicode character codes. If rxvt-unicode first sees a
407     japanese/chinese character, it might choose a japanese font for display.
408     Subsequent japanese characters will use that font. Now, many chinese
409     characters aren't represented in japanese fonts, so when the first
410     non-japanese character comes up, rxvt-unicode will look for a chinese
411     font -- unfortunately at this point, it will still use the japanese font
412     for chinese characters that are also in the japanese font.
413    
414     The workaround is easy: just tag a chinese font at the end of your font
415     list (see the previous question). The key is to view the font list as a
416     preference list: If you expect more japanese, list a japanese font
417     first. If you expect more chinese, put a chinese font first.
418    
419     In the future it might be possible to switch language preferences at
420     runtime (the internal data structure has no problem with using different
421     fonts for the same character at the same time, but no interface for this
422     has been designed yet).
423    
424     Until then, you might get away with switching fonts at runtime (see "Can
425     I switch the fonts at runtime?" later in this document).
426    
427 root 1.50 How can I make mplayer display video correctly?
428     We are working on it, in the meantime, as a workaround, use something
429     like:
430    
431     urxvt -b 600 -geometry 20x1 -e sh -c 'mplayer -wid $WINDOWID file...'
432    
433 root 1.71 Why is the cursor now blinking in emacs/vi/...?
434     This is likely caused by your editor/program's use of the "cvvis"
435     terminfo capability. Emacs uses it by default, as well as some versions
436     of vi and possibly other programs.
437    
438     In emacs, you can switch that off by adding this to your ".emacs" file:
439    
440     (setq visible-cursor nil)
441    
442     For other programs, if they do not have an option, your have to remove
443     the "cvvis" capability from the terminfo description.
444    
445     When urxvt first added the blinking cursor option, it didn't add a
446     "cvvis" capability, which served no purpose before. Version 9.21
447     introduced "cvvis" (and the ability to control blinking independent of
448     cursor shape) for compatibility with other terminals, which
449     traditionally use a blinking cursor for "cvvis". This also reflects the
450     intent of programs such as emacs, who expect "cvvis" to enable a
451     blinking cursor.
452    
453 root 1.42 Keyboard, Mouse & User Interaction
454     The new selection selects pieces that are too big, how can I select single words?
455     If you want to select e.g. alphanumeric words, you can use the following
456     setting:
457    
458     URxvt.selection.pattern-0: ([[:word:]]+)
459    
460     If you click more than twice, the selection will be extended more and
461     more.
462    
463     To get a selection that is very similar to the old code, try this
464     pattern:
465    
466     URxvt.selection.pattern-0: ([^"&'()*,;<=>?@[\\\\]^`{|})]+)
467    
468 root 1.53 Please also note that the *LeftClick Shift-LeftClick* combination also
469 root 1.42 selects words like the old code.
470    
471     I don't like the new selection/popups/hotkeys/perl, how do I change/disable it?
472     You can disable the perl extension completely by setting the
473     perl-ext-common resource to the empty string, which also keeps
474     rxvt-unicode from initialising perl, saving memory.
475    
476     If you only want to disable specific features, you first have to
477     identify which perl extension is responsible. For this, read the section
478     PREPACKAGED EXTENSIONS in the urxvtperl(3) manpage. For example, to
479     disable the selection-popup and option-popup, specify this
480     perl-ext-common resource:
481    
482     URxvt.perl-ext-common: default,-selection-popup,-option-popup
483    
484     This will keep the default extensions, but disable the two popup
485     extensions. Some extensions can also be configured, for example,
486     scrollback search mode is triggered by M-s. You can move it to any other
487 root 1.72 combination by adding a keysym resource that binds the desired
488     combination to the "start" action of "searchable-scrollback" and another
489     one that binds M-s to the "builtin:" action:
490 root 1.42
491 root 1.72 URxvt.keysym.CM-s: searchable-scrollback:start
492     URxvt.keysym.M-s: builtin:
493 root 1.42
494     The cursor moves when selecting text in the current input line, how do I switch this off?
495     See next entry.
496    
497     During rlogin/ssh/telnet/etc. sessions, clicking near the cursor outputs strange escape sequences, how do I fix this?
498     These are caused by the "readline" perl extension. Under normal
499     circumstances, it will move your cursor around when you click into the
500     line that contains it. It tries hard not to do this at the wrong moment,
501     but when running a program that doesn't parse cursor movements or in
502     some cases during rlogin sessions, it fails to detect this properly.
503    
504 root 1.43 You can permanently switch this feature off by disabling the "readline"
505 root 1.42 extension:
506    
507     URxvt.perl-ext-common: default,-readline
508    
509 root 1.70 My numeric keypad acts weird and generates differing output?
510     Some Debian GNU/Linux users seem to have this problem, although no
511 root 1.42 specific details were reported so far. It is possible that this is
512 root 1.43 caused by the wrong "TERM" setting, although the details of whether and
513 root 1.42 how this can happen are unknown, as "TERM=rxvt" should offer a
514     compatible keymap. See the answer to the previous question, and please
515     report if that helped.
516    
517     My Compose (Multi_key) key is no longer working.
518     The most common causes for this are that either your locale is not set
519 root 1.69 correctly, or you specified a preeditType that is not supported by your
520 root 1.42 input method. For example, if you specified OverTheSpot and your input
521     method (e.g. the default input method handling Compose keys) does not
522     support this (for instance because it is not visual), then rxvt-unicode
523     will continue without an input method.
524    
525 root 1.69 In this case either do not specify a preeditType or specify more than
526 root 1.42 one pre-edit style, such as OverTheSpot,Root,None.
527    
528 root 1.57 If it still doesn't work, then maybe your input method doesn't support
529     compose sequences - to fall back to the built-in one, make sure you
530     don't specify an input method via "-im" or "XMODIFIERS".
531    
532 root 1.42 I cannot type "Ctrl-Shift-2" to get an ASCII NUL character due to ISO 14755
533     Either try "Ctrl-2" alone (it often is mapped to ASCII NUL even on
534     international keyboards) or simply use ISO 14755 support to your
535     advantage, typing <Ctrl-Shift-0> to get a ASCII NUL. This works for
536     other codes, too, such as "Ctrl-Shift-1-d" to type the default telnet
537     escape character and so on.
538    
539     Mouse cut/paste suddenly no longer works.
540     Make sure that mouse reporting is actually turned off since killing some
541 sf-exg 1.64 editors prematurely may leave it active. I've heard that tcsh may use
542     mouse reporting unless it is otherwise specified. A quick check is to
543     see if cut/paste works when the Alt or Shift keys are pressed.
544 root 1.42
545     What's with the strange Backspace/Delete key behaviour?
546 root 1.43 Assuming that the physical Backspace key corresponds to the Backspace
547 root 1.42 keysym (not likely for Linux ... see the following question) there are
548     two standard values that can be used for Backspace: "^H" and "^?".
549    
550     Historically, either value is correct, but rxvt-unicode adopts the
551 root 1.47 debian policy of using "^?" when unsure, because it's the one and only
552 root 1.42 correct choice :).
553    
554 root 1.60 It is possible to toggle between "^H" and "^?" with the DECBKM private
555     mode:
556 root 1.42
557     # use Backspace = ^H
558     $ stty erase ^H
559 root 1.67 $ printf "\e[?67h"
560 root 1.42
561     # use Backspace = ^?
562     $ stty erase ^?
563 root 1.67 $ printf "\e[?67l"
564 root 1.42
565     This helps satisfy some of the Backspace discrepancies that occur, but
566     if you use Backspace = "^H", make sure that the termcap/terminfo value
567     properly reflects that.
568    
569     The Delete key is a another casualty of the ill-defined Backspace
570     problem. To avoid confusion between the Backspace and Delete keys, the
571     Delete key has been assigned an escape sequence to match the vt100 for
572     Execute ("ESC [ 3 ~") and is in the supplied termcap/terminfo.
573    
574     Some other Backspace problems:
575    
576     some editors use termcap/terminfo, some editors (vim I'm told) expect
577     Backspace = ^H, GNU Emacs (and Emacs-like editors) use ^H for help.
578    
579     Perhaps someday this will all be resolved in a consistent manner.
580    
581     I don't like the key-bindings. How do I change them?
582     There are some compile-time selections available via configure. Unless
583     you have run "configure" with the "--disable-resources" option you can
584     use the `keysym' resource to alter the keystrings associated with
585     keysyms.
586    
587     Here's an example for a URxvt session started using "urxvt -name URxvt"
588    
589 sf-exg 1.64 URxvt.keysym.Prior: \033[5~
590     URxvt.keysym.Next: \033[6~
591     URxvt.keysym.Home: \033[7~
592     URxvt.keysym.End: \033[8~
593     URxvt.keysym.Up: \033[A
594     URxvt.keysym.Down: \033[B
595     URxvt.keysym.Right: \033[C
596     URxvt.keysym.Left: \033[D
597 root 1.42
598     See some more examples in the documentation for the keysym resource.
599    
600     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
601     KP_Insert == Insert
602     F22 == Print
603     F27 == Home
604     F29 == Prior
605     F33 == End
606     F35 == Next
607    
608     Rather than have rxvt-unicode try to accommodate all the various
609     possible keyboard mappings, it is better to use `xmodmap' to remap the
610     keys as required for your particular machine.
611    
612     Terminal Configuration
613     Can I see a typical configuration?
614     The default configuration tries to be xterm-like, which I don't like
615     that much, but it's least surprise to regular users.
616    
617     As a rxvt or rxvt-unicode user, you are practically supposed to invest
618     time into customising your terminal. To get you started, here is the
619     author's .Xdefaults entries, with comments on what they do. It's
620     certainly not *typical*, but what's typical...
621    
622     URxvt.cutchars: "()*,<>[]{}|'
623     URxvt.print-pipe: cat >/tmp/xxx
624    
625     These are just for testing stuff.
626    
627     URxvt.imLocale: ja_JP.UTF-8
628     URxvt.preeditType: OnTheSpot,None
629    
630     This tells rxvt-unicode to use a special locale when communicating with
631     the X Input Method, and also tells it to only use the OnTheSpot pre-edit
632     type, which requires the "xim-onthespot" perl extension but rewards me
633     with correct-looking fonts.
634    
635     URxvt.perl-lib: /root/lib/urxvt
636     URxvt.perl-ext-common: default,selection-autotransform,selection-pastebin,xim-onthespot,remote-clipboard
637     URxvt.selection.pattern-0: ( at .*? line \\d+)
638     URxvt.selection.pattern-1: ^(/[^:]+):\
639     URxvt.selection-autotransform.0: s/^([^:[:space:]]+):(\\d+):?$/:e \\Q$1\\E\\x0d:$2\\x0d/
640     URxvt.selection-autotransform.1: s/^ at (.*?) line (\\d+)$/:e \\Q$1\\E\\x0d:$2\\x0d/
641    
642     This is my perl configuration. The first two set the perl library
643     directory and also tells urxvt to use a large number of extensions. I
644     develop for myself mostly, so I actually use most of the extensions I
645     write.
646    
647     The selection stuff mainly makes the selection perl-error-message aware
648 root 1.43 and tells it to convert perl error messages into vi-commands to load the
649 root 1.58 relevant file and go to the error line number.
650 root 1.42
651     URxvt.scrollstyle: plain
652     URxvt.secondaryScroll: true
653    
654     As the documentation says: plain is the preferred scrollbar for the
655 root 1.43 author. The "secondaryScroll" configures urxvt to scroll in full-screen
656     apps, like screen, so lines scrolled out of screen end up in urxvt's
657 root 1.42 scrollback buffer.
658    
659     URxvt.background: #000000
660     URxvt.foreground: gray90
661     URxvt.color7: gray90
662     URxvt.colorBD: #ffffff
663     URxvt.cursorColor: #e0e080
664     URxvt.throughColor: #8080f0
665     URxvt.highlightColor: #f0f0f0
666    
667     Some colours. Not sure which ones are being used or even non-defaults,
668     but these are in my .Xdefaults. Most notably, they set
669     foreground/background to light gray/black, and also make sure that the
670     colour 7 matches the default foreground colour.
671    
672     URxvt.underlineColor: yellow
673    
674     Another colour, makes underline lines look different. Sometimes hurts,
675     but is mostly a nice effect.
676    
677     URxvt.geometry: 154x36
678     URxvt.loginShell: false
679     URxvt.meta: ignore
680     URxvt.utmpInhibit: true
681    
682     Uh, well, should be mostly self-explanatory. By specifying some defaults
683     manually, I can quickly switch them for testing.
684    
685     URxvt.saveLines: 8192
686    
687     A large scrollback buffer is essential. Really.
688    
689     URxvt.mapAlert: true
690    
691     The only case I use it is for my IRC window, which I like to keep
692     iconified till people msg me (which beeps).
693    
694     URxvt.visualBell: true
695    
696     The audible bell is often annoying, especially when in a crowd.
697    
698     URxvt.insecure: true
699    
700     Please don't hack my mutt! Ooops...
701    
702     URxvt.pastableTabs: false
703    
704     I once thought this is a great idea.
705    
706     urxvt.font: 9x15bold,\
707     -misc-fixed-bold-r-normal--15-140-75-75-c-90-iso10646-1,\
708     -misc-fixed-medium-r-normal--15-140-75-75-c-90-iso10646-1, \
709     [codeset=JISX0208]xft:Kochi Gothic, \
710     xft:Bitstream Vera Sans Mono:autohint=true, \
711     xft:Code2000:antialias=false
712     urxvt.boldFont: -xos4-terminus-bold-r-normal--14-140-72-72-c-80-iso8859-15
713     urxvt.italicFont: xft:Bitstream Vera Sans Mono:italic:autohint=true
714     urxvt.boldItalicFont: xft:Bitstream Vera Sans Mono:bold:italic:autohint=true
715    
716     I wrote rxvt-unicode to be able to specify fonts exactly. So don't be
717 root 1.43 overwhelmed. A special note: the "9x15bold" mentioned above is actually
718 root 1.42 the version from XFree-3.3, as XFree-4 replaced it by a totally
719     different font (different glyphs for ";" and many other harmless
720     characters), while the second font is actually the "9x15bold" from
721     XFree4/XOrg. The bold version has less chars than the medium version, so
722 root 1.43 I use it for rare characters, too. When editing sources with vim, I use
723 root 1.42 italic for comments and other stuff, which looks quite good with
724     Bitstream Vera anti-aliased.
725    
726     Terminus is a quite bad font (many very wrong glyphs), but for most of
727     my purposes, it works, and gives a different look, as my normal
728     (Non-bold) font is already bold, and I want to see a difference between
729     bold and normal fonts.
730    
731     Please note that I used the "urxvt" instance name and not the "URxvt"
732 root 1.58 class name. That is because I use different configs for different
733 root 1.42 purposes, for example, my IRC window is started with "-name IRC", and
734     uses these defaults:
735    
736     IRC*title: IRC
737     IRC*geometry: 87x12+535+542
738     IRC*saveLines: 0
739     IRC*mapAlert: true
740     IRC*font: suxuseuro
741     IRC*boldFont: suxuseuro
742     IRC*colorBD: white
743     IRC*keysym.M-C-1: command:\033]710;suxuseuro\007\033]711;suxuseuro\007
744     IRC*keysym.M-C-2: command:\033]710;9x15bold\007\033]711;9x15bold\007
745    
746 root 1.57 "Alt-Ctrl-1" and "Alt-Ctrl-2" switch between two different font sizes.
747 root 1.42 "suxuseuro" allows me to keep an eye (and actually read) stuff while
748     keeping a very small window. If somebody pastes something complicated
749     (e.g. japanese), I temporarily switch to a larger font.
750    
751     The above is all in my ".Xdefaults" (I don't use ".Xresources" nor
752     "xrdb"). I also have some resources in a separate ".Xdefaults-hostname"
753 root 1.60 file for different hosts, for example, on my main desktop, I use:
754 root 1.42
755     URxvt.keysym.C-M-q: command:\033[3;5;5t
756     URxvt.keysym.C-M-y: command:\033[3;5;606t
757     URxvt.keysym.C-M-e: command:\033[3;1605;5t
758     URxvt.keysym.C-M-c: command:\033[3;1605;606t
759     URxvt.keysym.C-M-p: perl:test
760    
761     The first for keysym definitions allow me to quickly bring some windows
762     in the layout I like most. Ion users might start laughing but will stop
763     immediately when I tell them that I use my own Fvwm2 module for much the
764     same effect as Ion provides, and I only very rarely use the above key
765     combinations :->
766    
767     Why doesn't rxvt-unicode read my resources?
768     Well, why, indeed? It does, in a way very similar to other X
769     applications. Most importantly, this means that if you or your OS loads
770     resources into the X display (the right way to do it), rxvt-unicode will
771     ignore any resource files in your home directory. It will only read
772     $HOME/.Xdefaults when no resources are attached to the display.
773    
774     If you have or use an $HOME/.Xresources file, chances are that resources
775     are loaded into your X-server. In this case, you have to re-login after
776     every change (or run xrdb -merge $HOME/.Xresources).
777    
778     Also consider the form resources have to use:
779    
780     URxvt.resource: value
781    
782     If you want to use another form (there are lots of different ways of
783 root 1.43 specifying resources), make sure you understand whether and why it
784     works. If unsure, use the form above.
785 root 1.42
786     When I log-in to another system it tells me about missing terminfo data?
787     The terminal description used by rxvt-unicode is not as widely available
788     as that for xterm, or even rxvt (for which the same problem often
789     arises).
790    
791     The correct solution for this problem is to install the terminfo, this
792 root 1.57 can be done by simply installing rxvt-unicode on the remote system as
793     well (in case you have a nice package manager ready), or you can install
794     the terminfo database manually like this (with ncurses infocmp. works as
795     user and root):
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 root 1.44 One some systems you might need to set $TERMINFO to the full path of
801 root 1.70 $HOME/.terminfo for this to work.
802 root 1.44
803 root 1.42 If you cannot or do not want to do this, then you can simply set
804     "TERM=rxvt" or even "TERM=xterm", and live with the small number of
805     problems arising, which includes wrong keymapping, less and different
806     colours and some refresh errors in fullscreen applications. It's a nice
807     quick-and-dirty workaround for rare cases, though.
808    
809     If you always want to do this (and are fine with the consequences) you
810     can either recompile rxvt-unicode with the desired TERM value or use a
811     resource to set it:
812    
813     URxvt.termName: rxvt
814    
815     If you don't plan to use rxvt (quite common...) you could also replace
816     the rxvt terminfo file with the rxvt-unicode one and use "TERM=rxvt".
817    
818 root 1.57 nano fails with "Error opening terminal: rxvt-unicode"
819     This exceptionally confusing and useless error message is printed by
820     nano when it can't find the terminfo database. Nothing is wrong with
821     your terminal, read the previous answer for a solution.
822    
823 root 1.42 "tic" outputs some error when compiling the terminfo entry.
824     Most likely it's the empty definition for "enacs=". Just replace it by
825     "enacs=\E[0@" and try again.
826    
827     "bash"'s readline does not work correctly under urxvt.
828     See next entry.
829    
830     I need a termcap file entry.
831     One reason you might want this is that some distributions or operating
832     systems still compile some programs using the long-obsoleted termcap
833 root 1.72 library (Fedora's bash is one example) and rely on a termcap entry for
834     "rxvt-unicode".
835 root 1.42
836 root 1.43 You could use rxvt's termcap entry with reasonable results in many
837     cases. You can also create a termcap entry by using terminfo's infocmp
838     program like this:
839 root 1.42
840     infocmp -C rxvt-unicode
841    
842 root 1.55 Or you could use the termcap entry in doc/etc/rxvt-unicode.termcap,
843     generated by the command above.
844 root 1.42
845     Why does "ls" no longer have coloured output?
846     The "ls" in the GNU coreutils unfortunately doesn't use terminfo to
847 root 1.43 decide whether a terminal has colour, but uses its own configuration
848 root 1.42 file. Needless to say, "rxvt-unicode" is not in its default file (among
849     with most other terminals supporting colour). Either add:
850    
851     TERM rxvt-unicode
852    
853     to "/etc/DIR_COLORS" or simply add:
854    
855     alias ls='ls --color=auto'
856    
857     to your ".profile" or ".bashrc".
858    
859     Why doesn't vim/emacs etc. use the 88 colour mode?
860     See next entry.
861    
862     Why doesn't vim/emacs etc. make use of italic?
863     See next entry.
864    
865     Why are the secondary screen-related options not working properly?
866     Make sure you are using "TERM=rxvt-unicode". Some pre-packaged
867 root 1.70 distributions break rxvt-unicode by setting "TERM" to "rxvt", which
868     doesn't have these extra features. Unfortunately, some of these
869 root 1.42 furthermore fail to even install the "rxvt-unicode" terminfo file, so
870     you will need to install it on your own (See the question When I log-in
871     to another system it tells me about missing terminfo data? on how to do
872     this).
873    
874     Encoding / Locale / Input Method Issues
875     Rxvt-unicode does not seem to understand the selected encoding?
876     See next entry.
877    
878     Unicode does not seem to work?
879     If you encounter strange problems like typing an accented character but
880     getting two unrelated other characters or similar, or if program output
881     is subtly garbled, then you should check your locale settings.
882    
883     Rxvt-unicode must be started with the same "LC_CTYPE" setting as the
884 root 1.46 programs running in it. Often rxvt-unicode is started in the "C" locale,
885     while the login script running within the rxvt-unicode window changes
886     the locale to something else, e.g. "en_GB.UTF-8". Needless to say, this
887     is not going to work, and is the most common cause for problems.
888 root 1.42
889     The best thing is to fix your startup environment, as you will likely
890     run into other problems. If nothing works you can try this in your
891     .profile.
892    
893 root 1.46 printf '\33]701;%s\007' "$LC_CTYPE" # $LANG or $LC_ALL are worth a try, too
894 root 1.42
895     If this doesn't work, then maybe you use a "LC_CTYPE" specification not
896     supported on your systems. Some systems have a "locale" command which
897     displays this (also, "perl -e0" can be used to check locale settings, as
898     it will complain loudly if it cannot set the locale). If it displays
899     something like:
900    
901     locale: Cannot set LC_CTYPE to default locale: ...
902    
903     Then the locale you specified is not supported on your system.
904    
905     If nothing works and you are sure that everything is set correctly then
906     you will need to remember a little known fact: Some programs just don't
907     support locales :(
908    
909     How does rxvt-unicode determine the encoding to use?
910     See next entry.
911    
912     Is there an option to switch encodings?
913     Unlike some other terminals, rxvt-unicode has no encoding switch, and no
914     specific "utf-8" mode, such as xterm. In fact, it doesn't even know
915     about UTF-8 or any other encodings with respect to terminal I/O.
916    
917     The reasons is that there exists a perfectly fine mechanism for
918     selecting the encoding, doing I/O and (most important) communicating
919     this to all applications so everybody agrees on character properties
920     such as width and code number. This mechanism is the *locale*.
921     Applications not using that info will have problems (for example,
922     "xterm" gets the width of characters wrong as it uses its own,
923     locale-independent table under all locales).
924    
925     Rxvt-unicode uses the "LC_CTYPE" locale category to select encoding. All
926     programs doing the same (that is, most) will automatically agree in the
927     interpretation of characters.
928    
929     Unfortunately, there is no system-independent way to select locales, nor
930     is there a standard on how locale specifiers will look like.
931    
932     On most systems, the content of the "LC_CTYPE" environment variable
933     contains an arbitrary string which corresponds to an already-installed
934     locale. Common names for locales are "en_US.UTF-8", "de_DE.ISO-8859-15",
935     "ja_JP.EUC-JP", i.e. "language_country.encoding", but other forms (i.e.
936     "de" or "german") are also common.
937    
938     Rxvt-unicode ignores all other locale categories, and except for the
939     encoding, ignores country or language-specific settings, i.e.
940     "de_DE.UTF-8" and "ja_JP.UTF-8" are the normally same to rxvt-unicode.
941    
942     If you want to use a specific encoding you have to make sure you start
943     rxvt-unicode with the correct "LC_CTYPE" category.
944    
945     Can I switch locales at runtime?
946     Yes, using an escape sequence. Try something like this, which sets
947     rxvt-unicode's idea of "LC_CTYPE".
948    
949     printf '\33]701;%s\007' ja_JP.SJIS
950    
951     See also the previous answer.
952    
953     Sometimes this capability is rather handy when you want to work in one
954     locale (e.g. "de_DE.UTF-8") but some programs don't support it (e.g.
955     UTF-8). For example, I use this script to start "xjdic", which first
956     switches to a locale supported by xjdic and back later:
957    
958     printf '\33]701;%s\007' ja_JP.SJIS
959     xjdic -js
960     printf '\33]701;%s\007' de_DE.UTF-8
961    
962     You can also use xterm's "luit" program, which usually works fine,
963     except for some locales where character width differs between program-
964     and rxvt-unicode-locales.
965    
966     I have problems getting my input method working.
967     Try a search engine, as this is slightly different for every input
968     method server.
969    
970     Here is a checklist:
971    
972     - Make sure your locale *and* the imLocale are supported on your OS.
973     Try "locale -a" or check the documentation for your OS.
974    
975     - Make sure your locale or imLocale matches a locale supported by your
976     XIM.
977     For example, kinput2 does not support UTF-8 locales, you should use
978     "ja_JP.EUC-JP" or equivalent.
979    
980     - Make sure your XIM server is actually running.
981     - Make sure the "XMODIFIERS" environment variable is set correctly when
982     *starting* rxvt-unicode.
983     When you want to use e.g. kinput2, it must be set to "@im=kinput2".
984 root 1.43 For scim, use "@im=SCIM". You can see what input method servers are
985 root 1.42 running with this command:
986    
987     xprop -root XIM_SERVERS
988    
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 maintaining rxvt-unicode for distribution/OS XXX, any recommendation?
1012     You should build one binary with the default options. configure now
1013     enables most useful options, and the trend goes to making them
1014 root 1.43 runtime-switchable, too, so there is usually no drawback to enabling
1015 root 1.42 them, except higher disk and possibly memory usage. The perl interpreter
1016     should be enabled, as important functionality (menus, selection, likely
1017     more in the future) depends on it.
1018    
1019 root 1.58 You should not overwrite the "perl-ext-common" and "perl-ext" resources
1020 root 1.42 system-wide (except maybe with "defaults"). This will result in useful
1021     behaviour. If your distribution aims at low memory, add an empty
1022     "perl-ext-common" resource to the app-defaults file. This will keep the
1023     perl interpreter disabled until the user enables it.
1024    
1025     If you can/want build more binaries, I recommend building a minimal one
1026     with "--disable-everything" (very useful) and a maximal one with
1027     "--enable-everything" (less useful, it will be very big due to a lot of
1028     encodings built-in that increase download times and are rarely used).
1029    
1030     I need to make it setuid/setgid to support utmp/ptys on my OS, is this safe?
1031     It should be, starting with release 7.1. You are encouraged to properly
1032     install urxvt with privileges necessary for your OS now.
1033    
1034     When rxvt-unicode detects that it runs setuid or setgid, it will fork
1035     into a helper process for privileged operations (pty handling on some
1036     systems, utmp/wtmp/lastlog handling on others) and drop privileges
1037     immediately. This is much safer than most other terminals that keep
1038     privileges while running (but is more relevant to urxvt, as it contains
1039     things as perl interpreters, which might be "helpful" to attackers).
1040    
1041     This forking is done as the very first within main(), which is very
1042     early and reduces possible bugs to initialisation code run before
1043     main(), or things like the dynamic loader of your system, which should
1044     result in very little risk.
1045    
1046     I am on FreeBSD and rxvt-unicode does not seem to work at all.
1047     Rxvt-unicode requires the symbol "__STDC_ISO_10646__" to be defined in
1048     your compile environment, or an implementation that implements it,
1049 root 1.43 whether it defines the symbol or not. "__STDC_ISO_10646__" requires that
1050 root 1.42 wchar_t is represented as unicode.
1051    
1052 root 1.43 As you might have guessed, FreeBSD does neither define this symbol nor
1053 root 1.42 does it support it. Instead, it uses its own internal representation of
1054     wchar_t. This is, of course, completely fine with respect to standards.
1055    
1056     However, that means rxvt-unicode only works in "POSIX", "ISO-8859-1" and
1057 root 1.55 "UTF-8" locales under FreeBSD (which all use Unicode as wchar_t).
1058 root 1.42
1059     "__STDC_ISO_10646__" is the only sane way to support multi-language apps
1060     in an OS, as using a locale-dependent (and non-standardized)
1061     representation of wchar_t makes it impossible to convert between wchar_t
1062     (as used by X11 and your applications) and any other encoding without
1063     implementing OS-specific-wrappers for each and every locale. There
1064     simply are no APIs to convert wchar_t into anything except the current
1065     locale encoding.
1066    
1067     Some applications (such as the formidable mlterm) work around this by
1068     carrying their own replacement functions for character set handling with
1069     them, and either implementing OS-dependent hacks or doing multiple
1070     conversions (which is slow and unreliable in case the OS implements
1071     encodings slightly different than the terminal emulator).
1072    
1073     The rxvt-unicode author insists that the right way to fix this is in the
1074     system libraries once and for all, instead of forcing every app to carry
1075     complete replacements for them :)
1076    
1077     How can I use rxvt-unicode under cygwin?
1078     rxvt-unicode should compile and run out of the box on cygwin, using the
1079     X11 libraries that come with cygwin. libW11 emulation is no longer
1080     supported (and makes no sense, either, as it only supported a single
1081     font). I recommend starting the X-server in "-multiwindow" or
1082     "-rootless" mode instead, which will result in similar look&feel as the
1083     old libW11 emulation.
1084    
1085     At the time of this writing, cygwin didn't seem to support any
1086     multi-byte encodings (you might try "LC_CTYPE=C-UTF-8"), so you are
1087     likely limited to 8-bit encodings.
1088    
1089 root 1.49 Character widths are not correct.
1090     urxvt uses the system wcwidth function to know the information about the
1091     width of characters, so on systems with incorrect locale data you will
1092     likely get bad results. Two notorious examples are Solaris 9, where
1093     single-width characters like U+2514 are reported as double-width, and
1094     Darwin 8, where combining chars are reported having width 1.
1095    
1096     The solution is to upgrade your system or switch to a better one. A
1097     possibly working workaround is to use a wcwidth implementation like
1098    
1099     http://www.cl.cam.ac.uk/~mgk25/ucs/wcwidth.c
1100