ViewVC Help
View File | Revision Log | Show Annotations | Download File
/cvs/rxvt-unicode/README.FAQ
Revision: 1.61
Committed: Fri Oct 15 21:38:31 2010 UTC (13 years, 7 months ago) by root
Branch: MAIN
CVS Tags: rel-9_09
Changes since 1.60: +4 -4 lines
Log Message:
add clipboard-osc

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 sf-exg 1.59 How do I distinguish whether I'm running rxvt-unicode or a regular
75     xterm? I need this to decide about setting colours etc.
76 root 1.42 The original rxvt and rxvt-unicode always export the variable
77     "COLORTERM", so you can check and see if that is set. Note that several
78     programs, JED, slrn, Midnight Commander automatically check this
79 sf-exg 1.59 variable to decide whether or not to use colour.
80 root 1.42
81     How do I set the correct, full IP address for the DISPLAY variable?
82     If you've compiled rxvt-unicode with DISPLAY_IS_IP and have enabled
83     insecure mode then it is possible to use the following shell script
84     snippets to correctly set the display. If your version of rxvt-unicode
85     wasn't also compiled with ESCZ_ANSWER (as assumed in these snippets)
86     then the COLORTERM variable can be used to distinguish rxvt-unicode from
87     a regular xterm.
88    
89     Courtesy of Chuck Blake <cblake@BBN.COM> with the following shell script
90     snippets:
91    
92     # Bourne/Korn/POSIX family of shells:
93     [ ${TERM:-foo} = foo ] && TERM=xterm # assume an xterm if we don't know
94     if [ ${TERM:-foo} = xterm ]; then
95     stty -icanon -echo min 0 time 15 # see if enhanced rxvt or not
96     echo -n '^[Z'
97     read term_id
98     stty icanon echo
99     if [ ""${term_id} = '^[[?1;2C' -a ${DISPLAY:-foo} = foo ]; then
100     echo -n '^[[7n' # query the rxvt we are in for the DISPLAY string
101     read DISPLAY # set it in our local shell
102     fi
103     fi
104    
105     How do I compile the manual pages on my own?
106     You need to have a recent version of perl installed as /usr/bin/perl,
107 root 1.49 one that comes with pod2man, pod2text and pod2xhtml (from Pod::Xhtml).
108 root 1.48 Then go to the doc subdirectory and enter "make alldoc".
109 root 1.42
110     Isn't rxvt-unicode supposed to be small? Don't all those features bloat?
111     I often get asked about this, and I think, no, they didn't cause extra
112     bloat. If you compare a minimal rxvt and a minimal urxvt, you can see
113     that the urxvt binary is larger (due to some encoding tables always
114     being compiled in), but it actually uses less memory (RSS) after
115     startup. Even with "--disable-everything", this comparison is a bit
116     unfair, as many features unique to urxvt (locale, encoding conversion,
117     iso14755 etc.) are already in use in this mode.
118    
119     text data bss drs rss filename
120     98398 1664 24 15695 1824 rxvt --disable-everything
121     188985 9048 66616 18222 1788 urxvt --disable-everything
122    
123     When you "--enable-everything" (which *is* unfair, as this involves xft
124     and full locale/XIM support which are quite bloaty inside libX11 and my
125 root 1.43 libc), the two diverge, but not unreasonably so.
126 root 1.42
127     text data bss drs rss filename
128     163431 2152 24 20123 2060 rxvt --enable-everything
129     1035683 49680 66648 29096 3680 urxvt --enable-everything
130    
131     The very large size of the text section is explained by the east-asian
132     encoding tables, which, if unused, take up disk space but nothing else
133     and can be compiled out unless you rely on X11 core fonts that use those
134     encodings. The BSS size comes from the 64k emergency buffer that my c++
135     compiler allocates (but of course doesn't use unless you are out of
136     memory). Also, using an xft font instead of a core font immediately adds
137     a few megabytes of RSS. Xft indeed is responsible for a lot of RSS even
138     when not used.
139    
140     Of course, due to every character using two or four bytes instead of
141     one, a large scrollback buffer will ultimately make rxvt-unicode use
142     more memory.
143    
144     Compared to e.g. Eterm (5112k), aterm (3132k) and xterm (4680k), this
145     still fares rather well. And compared to some monsters like
146     gnome-terminal (21152k + extra 4204k in separate processes) or konsole
147     (22200k + extra 43180k in daemons that stay around after exit, plus half
148     a minute of startup time, including the hundreds of warnings it spits
149     out), it fares extremely well *g*.
150    
151     Why C++, isn't that unportable/bloated/uncool?
152     Is this a question? :) It comes up very often. The simple answer is: I
153     had to write it, and C++ allowed me to write and maintain it in a
154     fraction of the time and effort (which is a scarce resource for me). Put
155     even shorter: It simply wouldn't exist without C++.
156    
157     My personal stance on this is that C++ is less portable than C, but in
158     the case of rxvt-unicode this hardly matters, as its portability limits
159     are defined by things like X11, pseudo terminals, locale support and
160     unix domain sockets, which are all less portable than C++ itself.
161    
162     Regarding the bloat, see the above question: It's easy to write programs
163     in C that use gobs of memory, an certainly possible to write programs in
164     C++ that don't. C++ also often comes with large libraries, but this is
165     not necessarily the case with GCC. Here is what rxvt links against on my
166     system with a minimal config:
167    
168     libX11.so.6 => /usr/X11R6/lib/libX11.so.6 (0x00002aaaaabc3000)
169     libc.so.6 => /lib/libc.so.6 (0x00002aaaaadde000)
170     libdl.so.2 => /lib/libdl.so.2 (0x00002aaaab01d000)
171     /lib64/ld-linux-x86-64.so.2 (0x00002aaaaaaab000)
172    
173     And here is rxvt-unicode:
174    
175     libX11.so.6 => /usr/X11R6/lib/libX11.so.6 (0x00002aaaaabc3000)
176     libgcc_s.so.1 => /lib/libgcc_s.so.1 (0x00002aaaaada2000)
177 root 1.51 libc.so.6 => /lib/libc.so.6 (0x00002aaaaaeb0000)
178     libdl.so.2 => /lib/libdl.so.2 (0x00002aaaab0ee000)
179     /lib64/ld-linux-x86-64.so.2 (0x00002aaaaaaab000)
180 root 1.42
181     No large bloated libraries (of course, none were linked in statically),
182     except maybe libX11 :)
183    
184     Rendering, Font & Look and Feel Issues
185     I can't get transparency working, what am I doing wrong?
186 root 1.61 First of all, transparency isn't officially supported in rxvt-unicode,
187     so you are mostly on your own. Do not bug the author about it (but you
188     may bug everybody else). Also, if you can't get it working consider it a
189     rite of passage: ... and you failed.
190 root 1.42
191     Here are four ways to get transparency. Do read the manpage and option
192     descriptions for the programs mentioned and rxvt-unicode. Really, do it!
193    
194 root 1.51 1. Use transparent mode:
195 root 1.42
196     Esetroot wallpaper.jpg
197 root 1.51 urxvt -tr -tint red -sh 40
198 root 1.42
199     That works. If you think it doesn't, you lack transparency and tinting
200     support, or you are unable to read.
201    
202     2. Use a simple pixmap and emulate pseudo-transparency. This enables you
203     to use effects other than tinting and shading: Just shade/tint/whatever
204     your picture with gimp or any other tool:
205    
206 root 1.50 convert wallpaper.jpg -blur 20x20 -modulate 30 background.jpg
207 root 1.51 urxvt -pixmap "background.jpg;:root"
208 root 1.42
209 root 1.60 That works. If you think it doesn't, you lack libAfterImage or
210     GDK-PixBuf support, or you are unable to read.
211 root 1.42
212     3. Use an ARGB visual:
213    
214     urxvt -depth 32 -fg grey90 -bg rgba:0000/0000/4444/cccc
215    
216     This requires XFT support, and the support of your X-server. If that
217     doesn't work for you, blame Xorg and Keith Packard. ARGB visuals aren't
218     there yet, no matter what they claim. Rxvt-Unicode contains the
219 root 1.43 necessary bugfixes and workarounds for Xft and Xlib to make it work, but
220     that doesn't mean that your WM has the required kludges in place.
221 root 1.42
222     4. Use xcompmgr and let it do the job:
223    
224     xprop -frame -f _NET_WM_WINDOW_OPACITY 32c \
225     -set _NET_WM_WINDOW_OPACITY 0xc0000000
226    
227     Then click on a window you want to make transparent. Replace 0xc0000000
228     by other values to change the degree of opacity. If it doesn't work and
229     your server crashes, you got to keep the pieces.
230    
231     Why does rxvt-unicode sometimes leave pixel droppings?
232     Most fonts were not designed for terminal use, which means that
233     character size varies a lot. A font that is otherwise fine for terminal
234     use might contain some characters that are simply too wide. Rxvt-unicode
235     will avoid these characters. For characters that are just "a bit" too
236     wide a special "careful" rendering mode is used that redraws adjacent
237     characters.
238    
239     All of this requires that fonts do not lie about character sizes,
240     however: Xft fonts often draw glyphs larger than their acclaimed
241     bounding box, and rxvt-unicode has no way of detecting this (the correct
242     way is to ask for the character bounding box, which unfortunately is
243     wrong in these cases).
244    
245 root 1.43 It's not clear (to me at least), whether this is a bug in Xft, freetype,
246 root 1.42 or the respective font. If you encounter this problem you might try
247     using the "-lsp" option to give the font more height. If that doesn't
248     work, you might be forced to use a different font.
249    
250     All of this is not a problem when using X11 core fonts, as their
251     bounding box data is correct.
252    
253     How can I keep rxvt-unicode from using reverse video so much?
254     First of all, make sure you are running with the right terminal settings
255     ("TERM=rxvt-unicode"), which will get rid of most of these effects. Then
256     make sure you have specified colours for italic and bold, as otherwise
257     rxvt-unicode might use reverse video to simulate the effect:
258    
259     URxvt.colorBD: white
260     URxvt.colorIT: green
261    
262     Some programs assume totally weird colours (red instead of blue), how can I fix that?
263     For some unexplainable reason, some rare programs assume a very weird
264     colour palette when confronted with a terminal with more than the
265     standard 8 colours (rxvt-unicode supports 88). The right fix is, of
266     course, to fix these programs not to assume non-ISO colours without very
267     good reasons.
268    
269     In the meantime, you can either edit your "rxvt-unicode" terminfo
270     definition to only claim 8 colour support or use "TERM=rxvt", which will
271     fix colours but keep you from using other rxvt-unicode features.
272    
273     Can I switch the fonts at runtime?
274     Yes, using an escape sequence. Try something like this, which has the
275     same effect as using the "-fn" switch, and takes effect immediately:
276    
277     printf '\33]50;%s\007' "9x15bold,xft:Kochi Gothic"
278    
279     This is useful if you e.g. work primarily with japanese (and prefer a
280     japanese font), but you have to switch to chinese temporarily, where
281     japanese fonts would only be in your way.
282    
283     You can think of this as a kind of manual ISO-2022 switching.
284    
285     Why do italic characters look as if clipped?
286     Many fonts have difficulties with italic characters and hinting. For
287     example, the otherwise very nicely hinted font "xft:Bitstream Vera Sans
288     Mono" completely fails in its italic face. A workaround might be to
289     enable freetype autohinting, i.e. like this:
290    
291     URxvt.italicFont: xft:Bitstream Vera Sans Mono:italic:autohint=true
292     URxvt.boldItalicFont: xft:Bitstream Vera Sans Mono:bold:italic:autohint=true
293    
294     Can I speed up Xft rendering somehow?
295     Yes, the most obvious way to speed it up is to avoid Xft entirely, as it
296     is simply slow. If you still want Xft fonts you might try to disable
297     antialiasing (by appending ":antialias=false"), which saves lots of
298     memory and also speeds up rendering considerably.
299    
300     Rxvt-unicode doesn't seem to anti-alias its fonts, what is wrong?
301     Rxvt-unicode will use whatever you specify as a font. If it needs to
302     fall back to its default font search list it will prefer X11 core fonts,
303     because they are small and fast, and then use Xft fonts. It has
304     antialiasing disabled for most of them, because the author thinks they
305     look best that way.
306    
307     If you want antialiasing, you have to specify the fonts manually.
308    
309     What's with this bold/blink stuff?
310     If no bold colour is set via "colorBD:", bold will invert text using the
311     standard foreground colour.
312    
313     For the standard background colour, blinking will actually make the text
314 root 1.52 blink when compiled with "--enable-text-blink". Without
315     "--enable-text-blink", the blink attribute will be ignored.
316 root 1.42
317     On ANSI colours, bold/blink attributes are used to set high-intensity
318 sf-exg 1.59 foreground/background colours.
319 root 1.42
320 sf-exg 1.59 color0-7 are the low-intensity colours.
321 root 1.42
322 sf-exg 1.59 color8-15 are the corresponding high-intensity colours.
323 root 1.42
324 sf-exg 1.59 I don't like the screen colours. How do I change them?
325     You can change the screen colours at run-time using ~/.Xdefaults
326 root 1.42 resources (or as long-options).
327    
328     Here are values that are supposed to resemble a VGA screen, including
329     the murky brown that passes for low-intensity yellow:
330    
331     URxvt.color0: #000000
332     URxvt.color1: #A80000
333     URxvt.color2: #00A800
334     URxvt.color3: #A8A800
335     URxvt.color4: #0000A8
336     URxvt.color5: #A800A8
337     URxvt.color6: #00A8A8
338     URxvt.color7: #A8A8A8
339    
340     URxvt.color8: #000054
341     URxvt.color9: #FF0054
342     URxvt.color10: #00FF54
343     URxvt.color11: #FFFF54
344     URxvt.color12: #0000FF
345     URxvt.color13: #FF00FF
346     URxvt.color14: #00FFFF
347     URxvt.color15: #FFFFFF
348    
349 sf-exg 1.59 And here is a more complete set of non-standard colours.
350 root 1.42
351     URxvt.cursorColor: #dc74d1
352     URxvt.pointerColor: #dc74d1
353     URxvt.background: #0e0e0e
354     URxvt.foreground: #4ad5e1
355     URxvt.color0: #000000
356     URxvt.color8: #8b8f93
357     URxvt.color1: #dc74d1
358     URxvt.color9: #dc74d1
359     URxvt.color2: #0eb8c7
360     URxvt.color10: #0eb8c7
361     URxvt.color3: #dfe37e
362     URxvt.color11: #dfe37e
363     URxvt.color5: #9e88f0
364     URxvt.color13: #9e88f0
365     URxvt.color6: #73f7ff
366     URxvt.color14: #73f7ff
367     URxvt.color7: #e1dddd
368     URxvt.color15: #e1dddd
369    
370     They have been described (not by me) as "pretty girly".
371    
372     Why do some characters look so much different than others?
373     See next entry.
374    
375     How does rxvt-unicode choose fonts?
376     Most fonts do not contain the full range of Unicode, which is fine.
377     Chances are that the font you (or the admin/package maintainer of your
378     system/os) have specified does not cover all the characters you want to
379     display.
380    
381     rxvt-unicode makes a best-effort try at finding a replacement font.
382     Often the result is fine, but sometimes the chosen font looks
383     bad/ugly/wrong. Some fonts have totally strange characters that don't
384     resemble the correct glyph at all, and rxvt-unicode lacks the artificial
385     intelligence to detect that a specific glyph is wrong: it has to believe
386     the font that the characters it claims to contain indeed look correct.
387    
388     In that case, select a font of your taste and add it to the font list,
389     e.g.:
390    
391     urxvt -fn basefont,font2,font3...
392    
393     When rxvt-unicode sees a character, it will first look at the base font.
394     If the base font does not contain the character, it will go to the next
395     font, and so on. Specifying your own fonts will also speed up this
396     search and use less resources within rxvt-unicode and the X-server.
397    
398     The only limitation is that none of the fonts may be larger than the
399     base font, as the base font defines the terminal character cell size,
400     which must be the same due to the way terminals work.
401    
402     Why do some chinese characters look so different than others?
403     This is because there is a difference between script and language --
404     rxvt-unicode does not know which language the text that is output is, as
405     it only knows the unicode character codes. If rxvt-unicode first sees a
406     japanese/chinese character, it might choose a japanese font for display.
407     Subsequent japanese characters will use that font. Now, many chinese
408     characters aren't represented in japanese fonts, so when the first
409     non-japanese character comes up, rxvt-unicode will look for a chinese
410     font -- unfortunately at this point, it will still use the japanese font
411     for chinese characters that are also in the japanese font.
412    
413     The workaround is easy: just tag a chinese font at the end of your font
414     list (see the previous question). The key is to view the font list as a
415     preference list: If you expect more japanese, list a japanese font
416     first. If you expect more chinese, put a chinese font first.
417    
418     In the future it might be possible to switch language preferences at
419     runtime (the internal data structure has no problem with using different
420     fonts for the same character at the same time, but no interface for this
421     has been designed yet).
422    
423     Until then, you might get away with switching fonts at runtime (see "Can
424     I switch the fonts at runtime?" later in this document).
425    
426 root 1.50 How can I make mplayer display video correctly?
427     We are working on it, in the meantime, as a workaround, use something
428     like:
429    
430     urxvt -b 600 -geometry 20x1 -e sh -c 'mplayer -wid $WINDOWID file...'
431    
432 root 1.42 Keyboard, Mouse & User Interaction
433     The new selection selects pieces that are too big, how can I select single words?
434     If you want to select e.g. alphanumeric words, you can use the following
435     setting:
436    
437     URxvt.selection.pattern-0: ([[:word:]]+)
438    
439     If you click more than twice, the selection will be extended more and
440     more.
441    
442     To get a selection that is very similar to the old code, try this
443     pattern:
444    
445     URxvt.selection.pattern-0: ([^"&'()*,;<=>?@[\\\\]^`{|})]+)
446    
447 root 1.53 Please also note that the *LeftClick Shift-LeftClick* combination also
448 root 1.42 selects words like the old code.
449    
450     I don't like the new selection/popups/hotkeys/perl, how do I change/disable it?
451     You can disable the perl extension completely by setting the
452     perl-ext-common resource to the empty string, which also keeps
453     rxvt-unicode from initialising perl, saving memory.
454    
455     If you only want to disable specific features, you first have to
456     identify which perl extension is responsible. For this, read the section
457     PREPACKAGED EXTENSIONS in the urxvtperl(3) manpage. For example, to
458     disable the selection-popup and option-popup, specify this
459     perl-ext-common resource:
460    
461     URxvt.perl-ext-common: default,-selection-popup,-option-popup
462    
463     This will keep the default extensions, but disable the two popup
464     extensions. Some extensions can also be configured, for example,
465     scrollback search mode is triggered by M-s. You can move it to any other
466     combination either by setting the searchable-scrollback resource:
467    
468     URxvt.searchable-scrollback: CM-s
469    
470     The cursor moves when selecting text in the current input line, how do I switch this off?
471     See next entry.
472    
473     During rlogin/ssh/telnet/etc. sessions, clicking near the cursor outputs strange escape sequences, how do I fix this?
474     These are caused by the "readline" perl extension. Under normal
475     circumstances, it will move your cursor around when you click into the
476     line that contains it. It tries hard not to do this at the wrong moment,
477     but when running a program that doesn't parse cursor movements or in
478     some cases during rlogin sessions, it fails to detect this properly.
479    
480 root 1.43 You can permanently switch this feature off by disabling the "readline"
481 root 1.42 extension:
482    
483     URxvt.perl-ext-common: default,-readline
484    
485     My numerical keypad acts weird and generates differing output?
486     Some Debian GNUL/Linux users seem to have this problem, although no
487     specific details were reported so far. It is possible that this is
488 root 1.43 caused by the wrong "TERM" setting, although the details of whether and
489 root 1.42 how this can happen are unknown, as "TERM=rxvt" should offer a
490     compatible keymap. See the answer to the previous question, and please
491     report if that helped.
492    
493     My Compose (Multi_key) key is no longer working.
494     The most common causes for this are that either your locale is not set
495     correctly, or you specified a preeditStyle that is not supported by your
496     input method. For example, if you specified OverTheSpot and your input
497     method (e.g. the default input method handling Compose keys) does not
498     support this (for instance because it is not visual), then rxvt-unicode
499     will continue without an input method.
500    
501     In this case either do not specify a preeditStyle or specify more than
502     one pre-edit style, such as OverTheSpot,Root,None.
503    
504 root 1.57 If it still doesn't work, then maybe your input method doesn't support
505     compose sequences - to fall back to the built-in one, make sure you
506     don't specify an input method via "-im" or "XMODIFIERS".
507    
508 root 1.42 I cannot type "Ctrl-Shift-2" to get an ASCII NUL character due to ISO 14755
509     Either try "Ctrl-2" alone (it often is mapped to ASCII NUL even on
510     international keyboards) or simply use ISO 14755 support to your
511     advantage, typing <Ctrl-Shift-0> to get a ASCII NUL. This works for
512     other codes, too, such as "Ctrl-Shift-1-d" to type the default telnet
513     escape character and so on.
514    
515     Mouse cut/paste suddenly no longer works.
516     Make sure that mouse reporting is actually turned off since killing some
517     editors prematurely may leave the mouse in mouse report mode. I've heard
518     that tcsh may use mouse reporting unless it otherwise specified. A quick
519     check is to see if cut/paste works when the Alt or Shift keys are
520     depressed.
521    
522     What's with the strange Backspace/Delete key behaviour?
523 root 1.43 Assuming that the physical Backspace key corresponds to the Backspace
524 root 1.42 keysym (not likely for Linux ... see the following question) there are
525     two standard values that can be used for Backspace: "^H" and "^?".
526    
527     Historically, either value is correct, but rxvt-unicode adopts the
528 root 1.47 debian policy of using "^?" when unsure, because it's the one and only
529 root 1.42 correct choice :).
530    
531 root 1.60 It is possible to toggle between "^H" and "^?" with the DECBKM private
532     mode:
533 root 1.42
534     # use Backspace = ^H
535     $ stty erase ^H
536 root 1.60 $ echo -n "^[[?67h"
537 root 1.42
538     # use Backspace = ^?
539     $ stty erase ^?
540 root 1.60 $ echo -n "^[[?67l"
541 root 1.42
542     This helps satisfy some of the Backspace discrepancies that occur, but
543     if you use Backspace = "^H", make sure that the termcap/terminfo value
544     properly reflects that.
545    
546     The Delete key is a another casualty of the ill-defined Backspace
547     problem. To avoid confusion between the Backspace and Delete keys, the
548     Delete key has been assigned an escape sequence to match the vt100 for
549     Execute ("ESC [ 3 ~") and is in the supplied termcap/terminfo.
550    
551     Some other Backspace problems:
552    
553     some editors use termcap/terminfo, some editors (vim I'm told) expect
554     Backspace = ^H, GNU Emacs (and Emacs-like editors) use ^H for help.
555    
556     Perhaps someday this will all be resolved in a consistent manner.
557    
558     I don't like the key-bindings. How do I change them?
559     There are some compile-time selections available via configure. Unless
560     you have run "configure" with the "--disable-resources" option you can
561     use the `keysym' resource to alter the keystrings associated with
562     keysyms.
563    
564     Here's an example for a URxvt session started using "urxvt -name URxvt"
565    
566     URxvt.keysym.Home: \033[1~
567     URxvt.keysym.End: \033[4~
568     URxvt.keysym.C-apostrophe: \033<C-'>
569     URxvt.keysym.C-slash: \033<C-/>
570     URxvt.keysym.C-semicolon: \033<C-;>
571     URxvt.keysym.C-grave: \033<C-`>
572     URxvt.keysym.C-comma: \033<C-,>
573     URxvt.keysym.C-period: \033<C-.>
574     URxvt.keysym.C-0x60: \033<C-`>
575     URxvt.keysym.C-Tab: \033<C-Tab>
576     URxvt.keysym.C-Return: \033<C-Return>
577     URxvt.keysym.S-Return: \033<S-Return>
578     URxvt.keysym.S-space: \033<S-Space>
579     URxvt.keysym.M-Up: \033<M-Up>
580     URxvt.keysym.M-Down: \033<M-Down>
581     URxvt.keysym.M-Left: \033<M-Left>
582     URxvt.keysym.M-Right: \033<M-Right>
583     URxvt.keysym.M-C-0: list \033<M-C- 0123456789 >
584     URxvt.keysym.M-C-a: list \033<M-C- abcdefghijklmnopqrstuvwxyz >
585     URxvt.keysym.F12: command:\033]701;zh_CN.GBK\007
586    
587     See some more examples in the documentation for the keysym resource.
588    
589     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
590     KP_Insert == Insert
591     F22 == Print
592     F27 == Home
593     F29 == Prior
594     F33 == End
595     F35 == Next
596    
597     Rather than have rxvt-unicode try to accommodate all the various
598     possible keyboard mappings, it is better to use `xmodmap' to remap the
599     keys as required for your particular machine.
600    
601     Terminal Configuration
602     Can I see a typical configuration?
603     The default configuration tries to be xterm-like, which I don't like
604     that much, but it's least surprise to regular users.
605    
606     As a rxvt or rxvt-unicode user, you are practically supposed to invest
607     time into customising your terminal. To get you started, here is the
608     author's .Xdefaults entries, with comments on what they do. It's
609     certainly not *typical*, but what's typical...
610    
611     URxvt.cutchars: "()*,<>[]{}|'
612     URxvt.print-pipe: cat >/tmp/xxx
613    
614     These are just for testing stuff.
615    
616     URxvt.imLocale: ja_JP.UTF-8
617     URxvt.preeditType: OnTheSpot,None
618    
619     This tells rxvt-unicode to use a special locale when communicating with
620     the X Input Method, and also tells it to only use the OnTheSpot pre-edit
621     type, which requires the "xim-onthespot" perl extension but rewards me
622     with correct-looking fonts.
623    
624     URxvt.perl-lib: /root/lib/urxvt
625     URxvt.perl-ext-common: default,selection-autotransform,selection-pastebin,xim-onthespot,remote-clipboard
626     URxvt.selection.pattern-0: ( at .*? line \\d+)
627     URxvt.selection.pattern-1: ^(/[^:]+):\
628     URxvt.selection-autotransform.0: s/^([^:[:space:]]+):(\\d+):?$/:e \\Q$1\\E\\x0d:$2\\x0d/
629     URxvt.selection-autotransform.1: s/^ at (.*?) line (\\d+)$/:e \\Q$1\\E\\x0d:$2\\x0d/
630    
631     This is my perl configuration. The first two set the perl library
632     directory and also tells urxvt to use a large number of extensions. I
633     develop for myself mostly, so I actually use most of the extensions I
634     write.
635    
636     The selection stuff mainly makes the selection perl-error-message aware
637 root 1.43 and tells it to convert perl error messages into vi-commands to load the
638 root 1.58 relevant file and go to the error line number.
639 root 1.42
640     URxvt.scrollstyle: plain
641     URxvt.secondaryScroll: true
642    
643     As the documentation says: plain is the preferred scrollbar for the
644 root 1.43 author. The "secondaryScroll" configures urxvt to scroll in full-screen
645     apps, like screen, so lines scrolled out of screen end up in urxvt's
646 root 1.42 scrollback buffer.
647    
648     URxvt.background: #000000
649     URxvt.foreground: gray90
650     URxvt.color7: gray90
651     URxvt.colorBD: #ffffff
652     URxvt.cursorColor: #e0e080
653     URxvt.throughColor: #8080f0
654     URxvt.highlightColor: #f0f0f0
655    
656     Some colours. Not sure which ones are being used or even non-defaults,
657     but these are in my .Xdefaults. Most notably, they set
658     foreground/background to light gray/black, and also make sure that the
659     colour 7 matches the default foreground colour.
660    
661     URxvt.underlineColor: yellow
662    
663     Another colour, makes underline lines look different. Sometimes hurts,
664     but is mostly a nice effect.
665    
666     URxvt.geometry: 154x36
667     URxvt.loginShell: false
668     URxvt.meta: ignore
669     URxvt.utmpInhibit: true
670    
671     Uh, well, should be mostly self-explanatory. By specifying some defaults
672     manually, I can quickly switch them for testing.
673    
674     URxvt.saveLines: 8192
675    
676     A large scrollback buffer is essential. Really.
677    
678     URxvt.mapAlert: true
679    
680     The only case I use it is for my IRC window, which I like to keep
681     iconified till people msg me (which beeps).
682    
683     URxvt.visualBell: true
684    
685     The audible bell is often annoying, especially when in a crowd.
686    
687     URxvt.insecure: true
688    
689     Please don't hack my mutt! Ooops...
690    
691     URxvt.pastableTabs: false
692    
693     I once thought this is a great idea.
694    
695     urxvt.font: 9x15bold,\
696     -misc-fixed-bold-r-normal--15-140-75-75-c-90-iso10646-1,\
697     -misc-fixed-medium-r-normal--15-140-75-75-c-90-iso10646-1, \
698     [codeset=JISX0208]xft:Kochi Gothic, \
699     xft:Bitstream Vera Sans Mono:autohint=true, \
700     xft:Code2000:antialias=false
701     urxvt.boldFont: -xos4-terminus-bold-r-normal--14-140-72-72-c-80-iso8859-15
702     urxvt.italicFont: xft:Bitstream Vera Sans Mono:italic:autohint=true
703     urxvt.boldItalicFont: xft:Bitstream Vera Sans Mono:bold:italic:autohint=true
704    
705     I wrote rxvt-unicode to be able to specify fonts exactly. So don't be
706 root 1.43 overwhelmed. A special note: the "9x15bold" mentioned above is actually
707 root 1.42 the version from XFree-3.3, as XFree-4 replaced it by a totally
708     different font (different glyphs for ";" and many other harmless
709     characters), while the second font is actually the "9x15bold" from
710     XFree4/XOrg. The bold version has less chars than the medium version, so
711 root 1.43 I use it for rare characters, too. When editing sources with vim, I use
712 root 1.42 italic for comments and other stuff, which looks quite good with
713     Bitstream Vera anti-aliased.
714    
715     Terminus is a quite bad font (many very wrong glyphs), but for most of
716     my purposes, it works, and gives a different look, as my normal
717     (Non-bold) font is already bold, and I want to see a difference between
718     bold and normal fonts.
719    
720     Please note that I used the "urxvt" instance name and not the "URxvt"
721 root 1.58 class name. That is because I use different configs for different
722 root 1.42 purposes, for example, my IRC window is started with "-name IRC", and
723     uses these defaults:
724    
725     IRC*title: IRC
726     IRC*geometry: 87x12+535+542
727     IRC*saveLines: 0
728     IRC*mapAlert: true
729     IRC*font: suxuseuro
730     IRC*boldFont: suxuseuro
731     IRC*colorBD: white
732     IRC*keysym.M-C-1: command:\033]710;suxuseuro\007\033]711;suxuseuro\007
733     IRC*keysym.M-C-2: command:\033]710;9x15bold\007\033]711;9x15bold\007
734    
735 root 1.57 "Alt-Ctrl-1" and "Alt-Ctrl-2" switch between two different font sizes.
736 root 1.42 "suxuseuro" allows me to keep an eye (and actually read) stuff while
737     keeping a very small window. If somebody pastes something complicated
738     (e.g. japanese), I temporarily switch to a larger font.
739    
740     The above is all in my ".Xdefaults" (I don't use ".Xresources" nor
741     "xrdb"). I also have some resources in a separate ".Xdefaults-hostname"
742 root 1.60 file for different hosts, for example, on my main desktop, I use:
743 root 1.42
744     URxvt.keysym.C-M-q: command:\033[3;5;5t
745     URxvt.keysym.C-M-y: command:\033[3;5;606t
746     URxvt.keysym.C-M-e: command:\033[3;1605;5t
747     URxvt.keysym.C-M-c: command:\033[3;1605;606t
748     URxvt.keysym.C-M-p: perl:test
749    
750     The first for keysym definitions allow me to quickly bring some windows
751     in the layout I like most. Ion users might start laughing but will stop
752     immediately when I tell them that I use my own Fvwm2 module for much the
753     same effect as Ion provides, and I only very rarely use the above key
754     combinations :->
755    
756     Why doesn't rxvt-unicode read my resources?
757     Well, why, indeed? It does, in a way very similar to other X
758     applications. Most importantly, this means that if you or your OS loads
759     resources into the X display (the right way to do it), rxvt-unicode will
760     ignore any resource files in your home directory. It will only read
761     $HOME/.Xdefaults when no resources are attached to the display.
762    
763     If you have or use an $HOME/.Xresources file, chances are that resources
764     are loaded into your X-server. In this case, you have to re-login after
765     every change (or run xrdb -merge $HOME/.Xresources).
766    
767     Also consider the form resources have to use:
768    
769     URxvt.resource: value
770    
771     If you want to use another form (there are lots of different ways of
772 root 1.43 specifying resources), make sure you understand whether and why it
773     works. If unsure, use the form above.
774 root 1.42
775     When I log-in to another system it tells me about missing terminfo data?
776     The terminal description used by rxvt-unicode is not as widely available
777     as that for xterm, or even rxvt (for which the same problem often
778     arises).
779    
780     The correct solution for this problem is to install the terminfo, this
781 root 1.57 can be done by simply installing rxvt-unicode on the remote system as
782     well (in case you have a nice package manager ready), or you can install
783     the terminfo database manually like this (with ncurses infocmp. works as
784     user and root):
785 root 1.42
786     REMOTE=remotesystem.domain
787 root 1.44 infocmp rxvt-unicode | ssh $REMOTE "mkdir -p .terminfo && cat >/tmp/ti && tic /tmp/ti"
788 root 1.42
789 root 1.44 One some systems you might need to set $TERMINFO to the full path of
790     $HOME/.terminfo for this to work.
791    
792 root 1.42 If you cannot or do not want to do this, then you can simply set
793     "TERM=rxvt" or even "TERM=xterm", and live with the small number of
794     problems arising, which includes wrong keymapping, less and different
795     colours and some refresh errors in fullscreen applications. It's a nice
796     quick-and-dirty workaround for rare cases, though.
797    
798     If you always want to do this (and are fine with the consequences) you
799     can either recompile rxvt-unicode with the desired TERM value or use a
800     resource to set it:
801    
802     URxvt.termName: rxvt
803    
804     If you don't plan to use rxvt (quite common...) you could also replace
805     the rxvt terminfo file with the rxvt-unicode one and use "TERM=rxvt".
806    
807 root 1.57 nano fails with "Error opening terminal: rxvt-unicode"
808     This exceptionally confusing and useless error message is printed by
809     nano when it can't find the terminfo database. Nothing is wrong with
810     your terminal, read the previous answer for a solution.
811    
812 root 1.42 "tic" outputs some error when compiling the terminfo entry.
813     Most likely it's the empty definition for "enacs=". Just replace it by
814     "enacs=\E[0@" and try again.
815    
816     "bash"'s readline does not work correctly under urxvt.
817     See next entry.
818    
819     I need a termcap file entry.
820     One reason you might want this is that some distributions or operating
821     systems still compile some programs using the long-obsoleted termcap
822     library (Fedora Core's bash is one example) and rely on a termcap entry
823     for "rxvt-unicode".
824    
825 root 1.43 You could use rxvt's termcap entry with reasonable results in many
826     cases. You can also create a termcap entry by using terminfo's infocmp
827     program like this:
828 root 1.42
829     infocmp -C rxvt-unicode
830    
831 root 1.55 Or you could use the termcap entry in doc/etc/rxvt-unicode.termcap,
832     generated by the command above.
833 root 1.42
834     Why does "ls" no longer have coloured output?
835     The "ls" in the GNU coreutils unfortunately doesn't use terminfo to
836 root 1.43 decide whether a terminal has colour, but uses its own configuration
837 root 1.42 file. Needless to say, "rxvt-unicode" is not in its default file (among
838     with most other terminals supporting colour). Either add:
839    
840     TERM rxvt-unicode
841    
842     to "/etc/DIR_COLORS" or simply add:
843    
844     alias ls='ls --color=auto'
845    
846     to your ".profile" or ".bashrc".
847    
848     Why doesn't vim/emacs etc. use the 88 colour mode?
849     See next entry.
850    
851     Why doesn't vim/emacs etc. make use of italic?
852     See next entry.
853    
854     Why are the secondary screen-related options not working properly?
855     Make sure you are using "TERM=rxvt-unicode". Some pre-packaged
856     distributions (most notably Debian GNU/Linux) break rxvt-unicode by
857     setting "TERM" to "rxvt", which doesn't have these extra features.
858     Unfortunately, some of these (most notably, again, Debian GNU/Linux)
859     furthermore fail to even install the "rxvt-unicode" terminfo file, so
860     you will need to install it on your own (See the question When I log-in
861     to another system it tells me about missing terminfo data? on how to do
862     this).
863    
864     Encoding / Locale / Input Method Issues
865     Rxvt-unicode does not seem to understand the selected encoding?
866     See next entry.
867    
868     Unicode does not seem to work?
869     If you encounter strange problems like typing an accented character but
870     getting two unrelated other characters or similar, or if program output
871     is subtly garbled, then you should check your locale settings.
872    
873     Rxvt-unicode must be started with the same "LC_CTYPE" setting as the
874 root 1.46 programs running in it. Often rxvt-unicode is started in the "C" locale,
875     while the login script running within the rxvt-unicode window changes
876     the locale to something else, e.g. "en_GB.UTF-8". Needless to say, this
877     is not going to work, and is the most common cause for problems.
878 root 1.42
879     The best thing is to fix your startup environment, as you will likely
880     run into other problems. If nothing works you can try this in your
881     .profile.
882    
883 root 1.46 printf '\33]701;%s\007' "$LC_CTYPE" # $LANG or $LC_ALL are worth a try, too
884 root 1.42
885     If this doesn't work, then maybe you use a "LC_CTYPE" specification not
886     supported on your systems. Some systems have a "locale" command which
887     displays this (also, "perl -e0" can be used to check locale settings, as
888     it will complain loudly if it cannot set the locale). If it displays
889     something like:
890    
891     locale: Cannot set LC_CTYPE to default locale: ...
892    
893     Then the locale you specified is not supported on your system.
894    
895     If nothing works and you are sure that everything is set correctly then
896     you will need to remember a little known fact: Some programs just don't
897     support locales :(
898    
899     How does rxvt-unicode determine the encoding to use?
900     See next entry.
901    
902     Is there an option to switch encodings?
903     Unlike some other terminals, rxvt-unicode has no encoding switch, and no
904     specific "utf-8" mode, such as xterm. In fact, it doesn't even know
905     about UTF-8 or any other encodings with respect to terminal I/O.
906    
907     The reasons is that there exists a perfectly fine mechanism for
908     selecting the encoding, doing I/O and (most important) communicating
909     this to all applications so everybody agrees on character properties
910     such as width and code number. This mechanism is the *locale*.
911     Applications not using that info will have problems (for example,
912     "xterm" gets the width of characters wrong as it uses its own,
913     locale-independent table under all locales).
914    
915     Rxvt-unicode uses the "LC_CTYPE" locale category to select encoding. All
916     programs doing the same (that is, most) will automatically agree in the
917     interpretation of characters.
918    
919     Unfortunately, there is no system-independent way to select locales, nor
920     is there a standard on how locale specifiers will look like.
921    
922     On most systems, the content of the "LC_CTYPE" environment variable
923     contains an arbitrary string which corresponds to an already-installed
924     locale. Common names for locales are "en_US.UTF-8", "de_DE.ISO-8859-15",
925     "ja_JP.EUC-JP", i.e. "language_country.encoding", but other forms (i.e.
926     "de" or "german") are also common.
927    
928     Rxvt-unicode ignores all other locale categories, and except for the
929     encoding, ignores country or language-specific settings, i.e.
930     "de_DE.UTF-8" and "ja_JP.UTF-8" are the normally same to rxvt-unicode.
931    
932     If you want to use a specific encoding you have to make sure you start
933     rxvt-unicode with the correct "LC_CTYPE" category.
934    
935     Can I switch locales at runtime?
936     Yes, using an escape sequence. Try something like this, which sets
937     rxvt-unicode's idea of "LC_CTYPE".
938    
939     printf '\33]701;%s\007' ja_JP.SJIS
940    
941     See also the previous answer.
942    
943     Sometimes this capability is rather handy when you want to work in one
944     locale (e.g. "de_DE.UTF-8") but some programs don't support it (e.g.
945     UTF-8). For example, I use this script to start "xjdic", which first
946     switches to a locale supported by xjdic and back later:
947    
948     printf '\33]701;%s\007' ja_JP.SJIS
949     xjdic -js
950     printf '\33]701;%s\007' de_DE.UTF-8
951    
952     You can also use xterm's "luit" program, which usually works fine,
953     except for some locales where character width differs between program-
954     and rxvt-unicode-locales.
955    
956     I have problems getting my input method working.
957     Try a search engine, as this is slightly different for every input
958     method server.
959    
960     Here is a checklist:
961    
962     - Make sure your locale *and* the imLocale are supported on your OS.
963     Try "locale -a" or check the documentation for your OS.
964    
965     - Make sure your locale or imLocale matches a locale supported by your
966     XIM.
967     For example, kinput2 does not support UTF-8 locales, you should use
968     "ja_JP.EUC-JP" or equivalent.
969    
970     - Make sure your XIM server is actually running.
971     - Make sure the "XMODIFIERS" environment variable is set correctly when
972     *starting* rxvt-unicode.
973     When you want to use e.g. kinput2, it must be set to "@im=kinput2".
974 root 1.43 For scim, use "@im=SCIM". You can see what input method servers are
975 root 1.42 running with this command:
976    
977     xprop -root XIM_SERVERS
978    
979 root 1.54
980 root 1.42
981     My input method wants <some encoding> but I want UTF-8, what can I do?
982     You can specify separate locales for the input method and the rest of
983     the terminal, using the resource "imlocale":
984    
985     URxvt.imlocale: ja_JP.EUC-JP
986    
987     Now you can start your terminal with "LC_CTYPE=ja_JP.UTF-8" and still
988     use your input method. Please note, however, that, depending on your
989     Xlib version, you may not be able to input characters outside "EUC-JP"
990     in a normal way then, as your input method limits you.
991    
992     Rxvt-unicode crashes when the X Input Method changes or exits.
993     Unfortunately, this is unavoidable, as the XIM protocol is racy by
994     design. Applications can avoid some crashes at the expense of memory
995     leaks, and Input Methods can avoid some crashes by careful ordering at
996     exit time. kinput2 (and derived input methods) generally succeeds, while
997     SCIM (or similar input methods) fails. In the end, however, crashes
998     cannot be completely avoided even if both sides cooperate.
999    
1000     So the only workaround is not to kill your Input Method Servers.
1001    
1002     Operating Systems / Package Maintaining
1003     I am using Debian GNU/Linux and have a problem...
1004     The Debian GNU/Linux package of rxvt-unicode in sarge contains large
1005     patches that considerably change the behaviour of rxvt-unicode (but
1006     unfortunately this notice has been removed). Before reporting a bug to
1007     the original rxvt-unicode author please download and install the genuine
1008     version (<http://software.schmorp.de#rxvt-unicode>) and try to reproduce
1009     the problem. If you cannot, chances are that the problems are specific
1010     to Debian GNU/Linux, in which case it should be reported via the Debian
1011     Bug Tracking System (use "reportbug" to report the bug).
1012    
1013     For other problems that also affect the Debian package, you can and
1014     probably should use the Debian BTS, too, because, after all, it's also a
1015     bug in the Debian version and it serves as a reminder for other users
1016     that might encounter the same issue.
1017    
1018     I am maintaining rxvt-unicode for distribution/OS XXX, any recommendation?
1019     You should build one binary with the default options. configure now
1020     enables most useful options, and the trend goes to making them
1021 root 1.43 runtime-switchable, too, so there is usually no drawback to enabling
1022 root 1.42 them, except higher disk and possibly memory usage. The perl interpreter
1023     should be enabled, as important functionality (menus, selection, likely
1024     more in the future) depends on it.
1025    
1026 root 1.58 You should not overwrite the "perl-ext-common" and "perl-ext" resources
1027 root 1.42 system-wide (except maybe with "defaults"). This will result in useful
1028     behaviour. If your distribution aims at low memory, add an empty
1029     "perl-ext-common" resource to the app-defaults file. This will keep the
1030     perl interpreter disabled until the user enables it.
1031    
1032     If you can/want build more binaries, I recommend building a minimal one
1033     with "--disable-everything" (very useful) and a maximal one with
1034     "--enable-everything" (less useful, it will be very big due to a lot of
1035     encodings built-in that increase download times and are rarely used).
1036    
1037     I need to make it setuid/setgid to support utmp/ptys on my OS, is this safe?
1038     It should be, starting with release 7.1. You are encouraged to properly
1039     install urxvt with privileges necessary for your OS now.
1040    
1041     When rxvt-unicode detects that it runs setuid or setgid, it will fork
1042     into a helper process for privileged operations (pty handling on some
1043     systems, utmp/wtmp/lastlog handling on others) and drop privileges
1044     immediately. This is much safer than most other terminals that keep
1045     privileges while running (but is more relevant to urxvt, as it contains
1046     things as perl interpreters, which might be "helpful" to attackers).
1047    
1048     This forking is done as the very first within main(), which is very
1049     early and reduces possible bugs to initialisation code run before
1050     main(), or things like the dynamic loader of your system, which should
1051     result in very little risk.
1052    
1053     I am on FreeBSD and rxvt-unicode does not seem to work at all.
1054     Rxvt-unicode requires the symbol "__STDC_ISO_10646__" to be defined in
1055     your compile environment, or an implementation that implements it,
1056 root 1.43 whether it defines the symbol or not. "__STDC_ISO_10646__" requires that
1057 root 1.42 wchar_t is represented as unicode.
1058    
1059 root 1.43 As you might have guessed, FreeBSD does neither define this symbol nor
1060 root 1.42 does it support it. Instead, it uses its own internal representation of
1061     wchar_t. This is, of course, completely fine with respect to standards.
1062    
1063     However, that means rxvt-unicode only works in "POSIX", "ISO-8859-1" and
1064 root 1.55 "UTF-8" locales under FreeBSD (which all use Unicode as wchar_t).
1065 root 1.42
1066     "__STDC_ISO_10646__" is the only sane way to support multi-language apps
1067     in an OS, as using a locale-dependent (and non-standardized)
1068     representation of wchar_t makes it impossible to convert between wchar_t
1069     (as used by X11 and your applications) and any other encoding without
1070     implementing OS-specific-wrappers for each and every locale. There
1071     simply are no APIs to convert wchar_t into anything except the current
1072     locale encoding.
1073    
1074     Some applications (such as the formidable mlterm) work around this by
1075     carrying their own replacement functions for character set handling with
1076     them, and either implementing OS-dependent hacks or doing multiple
1077     conversions (which is slow and unreliable in case the OS implements
1078     encodings slightly different than the terminal emulator).
1079    
1080     The rxvt-unicode author insists that the right way to fix this is in the
1081     system libraries once and for all, instead of forcing every app to carry
1082     complete replacements for them :)
1083    
1084     How can I use rxvt-unicode under cygwin?
1085     rxvt-unicode should compile and run out of the box on cygwin, using the
1086     X11 libraries that come with cygwin. libW11 emulation is no longer
1087     supported (and makes no sense, either, as it only supported a single
1088     font). I recommend starting the X-server in "-multiwindow" or
1089     "-rootless" mode instead, which will result in similar look&feel as the
1090     old libW11 emulation.
1091    
1092     At the time of this writing, cygwin didn't seem to support any
1093     multi-byte encodings (you might try "LC_CTYPE=C-UTF-8"), so you are
1094     likely limited to 8-bit encodings.
1095    
1096 root 1.49 Character widths are not correct.
1097     urxvt uses the system wcwidth function to know the information about the
1098     width of characters, so on systems with incorrect locale data you will
1099     likely get bad results. Two notorious examples are Solaris 9, where
1100     single-width characters like U+2514 are reported as double-width, and
1101     Darwin 8, where combining chars are reported having width 1.
1102    
1103     The solution is to upgrade your system or switch to a better one. A
1104     possibly working workaround is to use a wcwidth implementation like
1105    
1106     http://www.cl.cam.ac.uk/~mgk25/ucs/wcwidth.c
1107