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Revision: 1.58
Committed: Tue Mar 16 00:54:46 2010 UTC (14 years, 2 months ago) by root
Branch: MAIN
Changes since 1.57: +3 -3 lines
Log Message:
update to libev 4.0

File Contents

# User Rev Content
1 root 1.42 RXVT-UNICODE/URXVT FREQUENTLY ASKED QUESTIONS
2     Meta, Features & Commandline Issues
3     My question isn't answered here, can I ask a human?
4     Before sending me mail, you could go to IRC: "irc.freenode.net", channel
5     "#rxvt-unicode" has some rxvt-unicode enthusiasts that might be
6     interested in learning about new and exciting problems (but not FAQs :).
7    
8 root 1.56 I use Gentoo, and I have a problem...
9     There are three big problems with Gentoo Linux: first of all, most if
10     not all Gentoo systems are completely broken (missing or mismatched
11     header files, broken compiler etc. are just the tip of the iceberg);
12     secondly, the Gentoo maintainer thinks it is a good idea to add broken
13     patches to the code; and lastly, it should be called Gentoo GNU/Linux.
14    
15     For these reasons, it is impossible to support rxvt-unicode on Gentoo.
16     Problems appearing on Gentoo systems will usually simply be ignored
17     unless they can be reproduced on non-Gentoo systems.
18    
19 root 1.42 Does it support tabs, can I have a tabbed rxvt-unicode?
20     Beginning with version 7.3, there is a perl extension that implements a
21     simple tabbed terminal. It is installed by default, so any of these
22     should give you tabs:
23    
24     urxvt -pe tabbed
25    
26     URxvt.perl-ext-common: default,tabbed
27    
28     It will also work fine with tabbing functionality of many window
29     managers or similar tabbing programs, and its embedding-features allow
30     it to be embedded into other programs, as witnessed by doc/rxvt-tabbed
31     or the upcoming "Gtk2::URxvt" perl module, which features a tabbed urxvt
32     (murxvt) terminal as an example embedding application.
33    
34     How do I know which rxvt-unicode version I'm using?
35     The version number is displayed with the usage (-h). Also the escape
36     sequence "ESC [ 8 n" sets the window title to the version number. When
37     using the urxvtc client, the version displayed is that of the daemon.
38    
39     Rxvt-unicode uses gobs of memory, how can I reduce that?
40     Rxvt-unicode tries to obey the rule of not charging you for something
41     you don't use. One thing you should try is to configure out all settings
42     that you don't need, for example, Xft support is a resource hog by
43     design, when used. Compiling it out ensures that no Xft font will be
44     loaded accidentally when rxvt-unicode tries to find a font for your
45     characters.
46    
47     Also, many people (me included) like large windows and even larger
48     scrollback buffers: Without "--enable-unicode3", rxvt-unicode will use 6
49     bytes per screen cell. For a 160x?? window this amounts to almost a
50     kilobyte per line. A scrollback buffer of 10000 lines will then (if
51     full) use 10 Megabytes of memory. With "--enable-unicode3" it gets
52     worse, as rxvt-unicode then uses 8 bytes per screen cell.
53    
54     How can I start urxvtd in a race-free way?
55     Try "urxvtd -f -o", which tells urxvtd to open the display, create the
56     listening socket and then fork.
57    
58 root 1.45 How can I start urxvtd automatically when I run urxvtc?
59 root 1.42 If you want to start urxvtd automatically whenever you run urxvtc and
60     the daemon isn't running yet, use this script:
61    
62     #!/bin/sh
63     urxvtc "$@"
64     if [ $? -eq 2 ]; then
65     urxvtd -q -o -f
66     urxvtc "$@"
67     fi
68    
69     This tries to create a new terminal, and if fails with exit status 2,
70     meaning it couldn't connect to the daemon, it will start the daemon and
71     re-run the command. Subsequent invocations of the script will re-use the
72     existing daemon.
73    
74 root 1.43 How do I distinguish whether I'm running rxvt-unicode or a regular xterm? I need this to decide about setting colors etc.
75 root 1.42 The original rxvt and rxvt-unicode always export the variable
76     "COLORTERM", so you can check and see if that is set. Note that several
77     programs, JED, slrn, Midnight Commander automatically check this
78     variable to decide whether or not to use color.
79    
80     How do I set the correct, full IP address for the DISPLAY variable?
81     If you've compiled rxvt-unicode with DISPLAY_IS_IP and have enabled
82     insecure mode then it is possible to use the following shell script
83     snippets to correctly set the display. If your version of rxvt-unicode
84     wasn't also compiled with ESCZ_ANSWER (as assumed in these snippets)
85     then the COLORTERM variable can be used to distinguish rxvt-unicode from
86     a regular xterm.
87    
88     Courtesy of Chuck Blake <cblake@BBN.COM> with the following shell script
89     snippets:
90    
91     # Bourne/Korn/POSIX family of shells:
92     [ ${TERM:-foo} = foo ] && TERM=xterm # assume an xterm if we don't know
93     if [ ${TERM:-foo} = xterm ]; then
94     stty -icanon -echo min 0 time 15 # see if enhanced rxvt or not
95     echo -n '^[Z'
96     read term_id
97     stty icanon echo
98     if [ ""${term_id} = '^[[?1;2C' -a ${DISPLAY:-foo} = foo ]; then
99     echo -n '^[[7n' # query the rxvt we are in for the DISPLAY string
100     read DISPLAY # set it in our local shell
101     fi
102     fi
103    
104     How do I compile the manual pages on my own?
105     You need to have a recent version of perl installed as /usr/bin/perl,
106 root 1.49 one that comes with pod2man, pod2text and pod2xhtml (from Pod::Xhtml).
107 root 1.48 Then go to the doc subdirectory and enter "make alldoc".
108 root 1.42
109     Isn't rxvt-unicode supposed to be small? Don't all those features bloat?
110     I often get asked about this, and I think, no, they didn't cause extra
111     bloat. If you compare a minimal rxvt and a minimal urxvt, you can see
112     that the urxvt binary is larger (due to some encoding tables always
113     being compiled in), but it actually uses less memory (RSS) after
114     startup. Even with "--disable-everything", this comparison is a bit
115     unfair, as many features unique to urxvt (locale, encoding conversion,
116     iso14755 etc.) are already in use in this mode.
117    
118     text data bss drs rss filename
119     98398 1664 24 15695 1824 rxvt --disable-everything
120     188985 9048 66616 18222 1788 urxvt --disable-everything
121    
122     When you "--enable-everything" (which *is* unfair, as this involves xft
123     and full locale/XIM support which are quite bloaty inside libX11 and my
124 root 1.43 libc), the two diverge, but not unreasonably so.
125 root 1.42
126     text data bss drs rss filename
127     163431 2152 24 20123 2060 rxvt --enable-everything
128     1035683 49680 66648 29096 3680 urxvt --enable-everything
129    
130     The very large size of the text section is explained by the east-asian
131     encoding tables, which, if unused, take up disk space but nothing else
132     and can be compiled out unless you rely on X11 core fonts that use those
133     encodings. The BSS size comes from the 64k emergency buffer that my c++
134     compiler allocates (but of course doesn't use unless you are out of
135     memory). Also, using an xft font instead of a core font immediately adds
136     a few megabytes of RSS. Xft indeed is responsible for a lot of RSS even
137     when not used.
138    
139     Of course, due to every character using two or four bytes instead of
140     one, a large scrollback buffer will ultimately make rxvt-unicode use
141     more memory.
142    
143     Compared to e.g. Eterm (5112k), aterm (3132k) and xterm (4680k), this
144     still fares rather well. And compared to some monsters like
145     gnome-terminal (21152k + extra 4204k in separate processes) or konsole
146     (22200k + extra 43180k in daemons that stay around after exit, plus half
147     a minute of startup time, including the hundreds of warnings it spits
148     out), it fares extremely well *g*.
149    
150     Why C++, isn't that unportable/bloated/uncool?
151     Is this a question? :) It comes up very often. The simple answer is: I
152     had to write it, and C++ allowed me to write and maintain it in a
153     fraction of the time and effort (which is a scarce resource for me). Put
154     even shorter: It simply wouldn't exist without C++.
155    
156     My personal stance on this is that C++ is less portable than C, but in
157     the case of rxvt-unicode this hardly matters, as its portability limits
158     are defined by things like X11, pseudo terminals, locale support and
159     unix domain sockets, which are all less portable than C++ itself.
160    
161     Regarding the bloat, see the above question: It's easy to write programs
162     in C that use gobs of memory, an certainly possible to write programs in
163     C++ that don't. C++ also often comes with large libraries, but this is
164     not necessarily the case with GCC. Here is what rxvt links against on my
165     system with a minimal config:
166    
167     libX11.so.6 => /usr/X11R6/lib/libX11.so.6 (0x00002aaaaabc3000)
168     libc.so.6 => /lib/libc.so.6 (0x00002aaaaadde000)
169     libdl.so.2 => /lib/libdl.so.2 (0x00002aaaab01d000)
170     /lib64/ld-linux-x86-64.so.2 (0x00002aaaaaaab000)
171    
172     And here is rxvt-unicode:
173    
174     libX11.so.6 => /usr/X11R6/lib/libX11.so.6 (0x00002aaaaabc3000)
175     libgcc_s.so.1 => /lib/libgcc_s.so.1 (0x00002aaaaada2000)
176 root 1.51 libc.so.6 => /lib/libc.so.6 (0x00002aaaaaeb0000)
177     libdl.so.2 => /lib/libdl.so.2 (0x00002aaaab0ee000)
178     /lib64/ld-linux-x86-64.so.2 (0x00002aaaaaaab000)
179 root 1.42
180     No large bloated libraries (of course, none were linked in statically),
181     except maybe libX11 :)
182    
183     Rendering, Font & Look and Feel Issues
184     I can't get transparency working, what am I doing wrong?
185 root 1.50 First of all, please address all transparency related issues to Sasha
186     Vasko at sasha@aftercode.net and do not bug the author about it. Also,
187     if you can't get it working consider it a rite of passage: ... and you
188     failed.
189 root 1.42
190     Here are four ways to get transparency. Do read the manpage and option
191     descriptions for the programs mentioned and rxvt-unicode. Really, do it!
192    
193 root 1.51 1. Use transparent mode:
194 root 1.42
195     Esetroot wallpaper.jpg
196 root 1.51 urxvt -tr -tint red -sh 40
197 root 1.42
198     That works. If you think it doesn't, you lack transparency and tinting
199     support, or you are unable to read.
200    
201     2. Use a simple pixmap and emulate pseudo-transparency. This enables you
202     to use effects other than tinting and shading: Just shade/tint/whatever
203     your picture with gimp or any other tool:
204    
205 root 1.50 convert wallpaper.jpg -blur 20x20 -modulate 30 background.jpg
206 root 1.51 urxvt -pixmap "background.jpg;:root"
207 root 1.42
208 root 1.51 That works. If you think it doesn't, you lack AfterImage support, or you
209     are unable to read.
210 root 1.42
211     3. Use an ARGB visual:
212    
213     urxvt -depth 32 -fg grey90 -bg rgba:0000/0000/4444/cccc
214    
215     This requires XFT support, and the support of your X-server. If that
216     doesn't work for you, blame Xorg and Keith Packard. ARGB visuals aren't
217     there yet, no matter what they claim. Rxvt-Unicode contains the
218 root 1.43 necessary bugfixes and workarounds for Xft and Xlib to make it work, but
219     that doesn't mean that your WM has the required kludges in place.
220 root 1.42
221     4. Use xcompmgr and let it do the job:
222    
223     xprop -frame -f _NET_WM_WINDOW_OPACITY 32c \
224     -set _NET_WM_WINDOW_OPACITY 0xc0000000
225    
226     Then click on a window you want to make transparent. Replace 0xc0000000
227     by other values to change the degree of opacity. If it doesn't work and
228     your server crashes, you got to keep the pieces.
229    
230     Why does rxvt-unicode sometimes leave pixel droppings?
231     Most fonts were not designed for terminal use, which means that
232     character size varies a lot. A font that is otherwise fine for terminal
233     use might contain some characters that are simply too wide. Rxvt-unicode
234     will avoid these characters. For characters that are just "a bit" too
235     wide a special "careful" rendering mode is used that redraws adjacent
236     characters.
237    
238     All of this requires that fonts do not lie about character sizes,
239     however: Xft fonts often draw glyphs larger than their acclaimed
240     bounding box, and rxvt-unicode has no way of detecting this (the correct
241     way is to ask for the character bounding box, which unfortunately is
242     wrong in these cases).
243    
244 root 1.43 It's not clear (to me at least), whether this is a bug in Xft, freetype,
245 root 1.42 or the respective font. If you encounter this problem you might try
246     using the "-lsp" option to give the font more height. If that doesn't
247     work, you might be forced to use a different font.
248    
249     All of this is not a problem when using X11 core fonts, as their
250     bounding box data is correct.
251    
252     How can I keep rxvt-unicode from using reverse video so much?
253     First of all, make sure you are running with the right terminal settings
254     ("TERM=rxvt-unicode"), which will get rid of most of these effects. Then
255     make sure you have specified colours for italic and bold, as otherwise
256     rxvt-unicode might use reverse video to simulate the effect:
257    
258     URxvt.colorBD: white
259     URxvt.colorIT: green
260    
261     Some programs assume totally weird colours (red instead of blue), how can I fix that?
262     For some unexplainable reason, some rare programs assume a very weird
263     colour palette when confronted with a terminal with more than the
264     standard 8 colours (rxvt-unicode supports 88). The right fix is, of
265     course, to fix these programs not to assume non-ISO colours without very
266     good reasons.
267    
268     In the meantime, you can either edit your "rxvt-unicode" terminfo
269     definition to only claim 8 colour support or use "TERM=rxvt", which will
270     fix colours but keep you from using other rxvt-unicode features.
271    
272     Can I switch the fonts at runtime?
273     Yes, using an escape sequence. Try something like this, which has the
274     same effect as using the "-fn" switch, and takes effect immediately:
275    
276     printf '\33]50;%s\007' "9x15bold,xft:Kochi Gothic"
277    
278     This is useful if you e.g. work primarily with japanese (and prefer a
279     japanese font), but you have to switch to chinese temporarily, where
280     japanese fonts would only be in your way.
281    
282     You can think of this as a kind of manual ISO-2022 switching.
283    
284     Why do italic characters look as if clipped?
285     Many fonts have difficulties with italic characters and hinting. For
286     example, the otherwise very nicely hinted font "xft:Bitstream Vera Sans
287     Mono" completely fails in its italic face. A workaround might be to
288     enable freetype autohinting, i.e. like this:
289    
290     URxvt.italicFont: xft:Bitstream Vera Sans Mono:italic:autohint=true
291     URxvt.boldItalicFont: xft:Bitstream Vera Sans Mono:bold:italic:autohint=true
292    
293     Can I speed up Xft rendering somehow?
294     Yes, the most obvious way to speed it up is to avoid Xft entirely, as it
295     is simply slow. If you still want Xft fonts you might try to disable
296     antialiasing (by appending ":antialias=false"), which saves lots of
297     memory and also speeds up rendering considerably.
298    
299     Rxvt-unicode doesn't seem to anti-alias its fonts, what is wrong?
300     Rxvt-unicode will use whatever you specify as a font. If it needs to
301     fall back to its default font search list it will prefer X11 core fonts,
302     because they are small and fast, and then use Xft fonts. It has
303     antialiasing disabled for most of them, because the author thinks they
304     look best that way.
305    
306     If you want antialiasing, you have to specify the fonts manually.
307    
308     What's with this bold/blink stuff?
309     If no bold colour is set via "colorBD:", bold will invert text using the
310     standard foreground colour.
311    
312     For the standard background colour, blinking will actually make the text
313 root 1.52 blink when compiled with "--enable-text-blink". Without
314     "--enable-text-blink", the blink attribute will be ignored.
315 root 1.42
316     On ANSI colours, bold/blink attributes are used to set high-intensity
317     foreground/background colors.
318    
319     color0-7 are the low-intensity colors.
320    
321     color8-15 are the corresponding high-intensity colors.
322    
323     I don't like the screen colors. How do I change them?
324     You can change the screen colors at run-time using ~/.Xdefaults
325     resources (or as long-options).
326    
327     Here are values that are supposed to resemble a VGA screen, including
328     the murky brown that passes for low-intensity yellow:
329    
330     URxvt.color0: #000000
331     URxvt.color1: #A80000
332     URxvt.color2: #00A800
333     URxvt.color3: #A8A800
334     URxvt.color4: #0000A8
335     URxvt.color5: #A800A8
336     URxvt.color6: #00A8A8
337     URxvt.color7: #A8A8A8
338    
339     URxvt.color8: #000054
340     URxvt.color9: #FF0054
341     URxvt.color10: #00FF54
342     URxvt.color11: #FFFF54
343     URxvt.color12: #0000FF
344     URxvt.color13: #FF00FF
345     URxvt.color14: #00FFFF
346     URxvt.color15: #FFFFFF
347    
348     And here is a more complete set of non-standard colors.
349    
350     URxvt.cursorColor: #dc74d1
351     URxvt.pointerColor: #dc74d1
352     URxvt.background: #0e0e0e
353     URxvt.foreground: #4ad5e1
354     URxvt.color0: #000000
355     URxvt.color8: #8b8f93
356     URxvt.color1: #dc74d1
357     URxvt.color9: #dc74d1
358     URxvt.color2: #0eb8c7
359     URxvt.color10: #0eb8c7
360     URxvt.color3: #dfe37e
361     URxvt.color11: #dfe37e
362     URxvt.color5: #9e88f0
363     URxvt.color13: #9e88f0
364     URxvt.color6: #73f7ff
365     URxvt.color14: #73f7ff
366     URxvt.color7: #e1dddd
367     URxvt.color15: #e1dddd
368    
369     They have been described (not by me) as "pretty girly".
370    
371     Why do some characters look so much different than others?
372     See next entry.
373    
374     How does rxvt-unicode choose fonts?
375     Most fonts do not contain the full range of Unicode, which is fine.
376     Chances are that the font you (or the admin/package maintainer of your
377     system/os) have specified does not cover all the characters you want to
378     display.
379    
380     rxvt-unicode makes a best-effort try at finding a replacement font.
381     Often the result is fine, but sometimes the chosen font looks
382     bad/ugly/wrong. Some fonts have totally strange characters that don't
383     resemble the correct glyph at all, and rxvt-unicode lacks the artificial
384     intelligence to detect that a specific glyph is wrong: it has to believe
385     the font that the characters it claims to contain indeed look correct.
386    
387     In that case, select a font of your taste and add it to the font list,
388     e.g.:
389    
390     urxvt -fn basefont,font2,font3...
391    
392     When rxvt-unicode sees a character, it will first look at the base font.
393     If the base font does not contain the character, it will go to the next
394     font, and so on. Specifying your own fonts will also speed up this
395     search and use less resources within rxvt-unicode and the X-server.
396    
397     The only limitation is that none of the fonts may be larger than the
398     base font, as the base font defines the terminal character cell size,
399     which must be the same due to the way terminals work.
400    
401     Why do some chinese characters look so different than others?
402     This is because there is a difference between script and language --
403     rxvt-unicode does not know which language the text that is output is, as
404     it only knows the unicode character codes. If rxvt-unicode first sees a
405     japanese/chinese character, it might choose a japanese font for display.
406     Subsequent japanese characters will use that font. Now, many chinese
407     characters aren't represented in japanese fonts, so when the first
408     non-japanese character comes up, rxvt-unicode will look for a chinese
409     font -- unfortunately at this point, it will still use the japanese font
410     for chinese characters that are also in the japanese font.
411    
412     The workaround is easy: just tag a chinese font at the end of your font
413     list (see the previous question). The key is to view the font list as a
414     preference list: If you expect more japanese, list a japanese font
415     first. If you expect more chinese, put a chinese font first.
416    
417     In the future it might be possible to switch language preferences at
418     runtime (the internal data structure has no problem with using different
419     fonts for the same character at the same time, but no interface for this
420     has been designed yet).
421    
422     Until then, you might get away with switching fonts at runtime (see "Can
423     I switch the fonts at runtime?" later in this document).
424    
425 root 1.50 How can I make mplayer display video correctly?
426     We are working on it, in the meantime, as a workaround, use something
427     like:
428    
429     urxvt -b 600 -geometry 20x1 -e sh -c 'mplayer -wid $WINDOWID file...'
430    
431 root 1.42 Keyboard, Mouse & User Interaction
432     The new selection selects pieces that are too big, how can I select single words?
433     If you want to select e.g. alphanumeric words, you can use the following
434     setting:
435    
436     URxvt.selection.pattern-0: ([[:word:]]+)
437    
438     If you click more than twice, the selection will be extended more and
439     more.
440    
441     To get a selection that is very similar to the old code, try this
442     pattern:
443    
444     URxvt.selection.pattern-0: ([^"&'()*,;<=>?@[\\\\]^`{|})]+)
445    
446 root 1.53 Please also note that the *LeftClick Shift-LeftClick* combination also
447 root 1.42 selects words like the old code.
448    
449     I don't like the new selection/popups/hotkeys/perl, how do I change/disable it?
450     You can disable the perl extension completely by setting the
451     perl-ext-common resource to the empty string, which also keeps
452     rxvt-unicode from initialising perl, saving memory.
453    
454     If you only want to disable specific features, you first have to
455     identify which perl extension is responsible. For this, read the section
456     PREPACKAGED EXTENSIONS in the urxvtperl(3) manpage. For example, to
457     disable the selection-popup and option-popup, specify this
458     perl-ext-common resource:
459    
460     URxvt.perl-ext-common: default,-selection-popup,-option-popup
461    
462     This will keep the default extensions, but disable the two popup
463     extensions. Some extensions can also be configured, for example,
464     scrollback search mode is triggered by M-s. You can move it to any other
465     combination either by setting the searchable-scrollback resource:
466    
467     URxvt.searchable-scrollback: CM-s
468    
469     The cursor moves when selecting text in the current input line, how do I switch this off?
470     See next entry.
471    
472     During rlogin/ssh/telnet/etc. sessions, clicking near the cursor outputs strange escape sequences, how do I fix this?
473     These are caused by the "readline" perl extension. Under normal
474     circumstances, it will move your cursor around when you click into the
475     line that contains it. It tries hard not to do this at the wrong moment,
476     but when running a program that doesn't parse cursor movements or in
477     some cases during rlogin sessions, it fails to detect this properly.
478    
479 root 1.43 You can permanently switch this feature off by disabling the "readline"
480 root 1.42 extension:
481    
482     URxvt.perl-ext-common: default,-readline
483    
484     My numerical keypad acts weird and generates differing output?
485     Some Debian GNUL/Linux users seem to have this problem, although no
486     specific details were reported so far. It is possible that this is
487 root 1.43 caused by the wrong "TERM" setting, although the details of whether and
488 root 1.42 how this can happen are unknown, as "TERM=rxvt" should offer a
489     compatible keymap. See the answer to the previous question, and please
490     report if that helped.
491    
492     My Compose (Multi_key) key is no longer working.
493     The most common causes for this are that either your locale is not set
494     correctly, or you specified a preeditStyle that is not supported by your
495     input method. For example, if you specified OverTheSpot and your input
496     method (e.g. the default input method handling Compose keys) does not
497     support this (for instance because it is not visual), then rxvt-unicode
498     will continue without an input method.
499    
500     In this case either do not specify a preeditStyle or specify more than
501     one pre-edit style, such as OverTheSpot,Root,None.
502    
503 root 1.57 If it still doesn't work, then maybe your input method doesn't support
504     compose sequences - to fall back to the built-in one, make sure you
505     don't specify an input method via "-im" or "XMODIFIERS".
506    
507 root 1.42 I cannot type "Ctrl-Shift-2" to get an ASCII NUL character due to ISO 14755
508     Either try "Ctrl-2" alone (it often is mapped to ASCII NUL even on
509     international keyboards) or simply use ISO 14755 support to your
510     advantage, typing <Ctrl-Shift-0> to get a ASCII NUL. This works for
511     other codes, too, such as "Ctrl-Shift-1-d" to type the default telnet
512     escape character and so on.
513    
514     Mouse cut/paste suddenly no longer works.
515     Make sure that mouse reporting is actually turned off since killing some
516     editors prematurely may leave the mouse in mouse report mode. I've heard
517     that tcsh may use mouse reporting unless it otherwise specified. A quick
518     check is to see if cut/paste works when the Alt or Shift keys are
519     depressed.
520    
521     What's with the strange Backspace/Delete key behaviour?
522 root 1.43 Assuming that the physical Backspace key corresponds to the Backspace
523 root 1.42 keysym (not likely for Linux ... see the following question) there are
524     two standard values that can be used for Backspace: "^H" and "^?".
525    
526     Historically, either value is correct, but rxvt-unicode adopts the
527 root 1.47 debian policy of using "^?" when unsure, because it's the one and only
528 root 1.42 correct choice :).
529    
530     Rxvt-unicode tries to inherit the current stty settings and uses the
531     value of `erase' to guess the value for backspace. If rxvt-unicode
532     wasn't started from a terminal (say, from a menu or by remote shell),
533     then the system value of `erase', which corresponds to CERASE in
534     <termios.h>, will be used (which may not be the same as your stty
535     setting).
536    
537     For starting a new rxvt-unicode:
538    
539     # use Backspace = ^H
540     $ stty erase ^H
541     $ urxvt
542    
543     # use Backspace = ^?
544     $ stty erase ^?
545     $ urxvt
546    
547     Toggle with "ESC [ 36 h" / "ESC [ 36 l".
548    
549     For an existing rxvt-unicode:
550    
551     # use Backspace = ^H
552     $ stty erase ^H
553     $ echo -n "^[[36h"
554    
555     # use Backspace = ^?
556     $ stty erase ^?
557     $ echo -n "^[[36l"
558    
559     This helps satisfy some of the Backspace discrepancies that occur, but
560     if you use Backspace = "^H", make sure that the termcap/terminfo value
561     properly reflects that.
562    
563     The Delete key is a another casualty of the ill-defined Backspace
564     problem. To avoid confusion between the Backspace and Delete keys, the
565     Delete key has been assigned an escape sequence to match the vt100 for
566     Execute ("ESC [ 3 ~") and is in the supplied termcap/terminfo.
567    
568     Some other Backspace problems:
569    
570     some editors use termcap/terminfo, some editors (vim I'm told) expect
571     Backspace = ^H, GNU Emacs (and Emacs-like editors) use ^H for help.
572    
573     Perhaps someday this will all be resolved in a consistent manner.
574    
575     I don't like the key-bindings. How do I change them?
576     There are some compile-time selections available via configure. Unless
577     you have run "configure" with the "--disable-resources" option you can
578     use the `keysym' resource to alter the keystrings associated with
579     keysyms.
580    
581     Here's an example for a URxvt session started using "urxvt -name URxvt"
582    
583     URxvt.keysym.Home: \033[1~
584     URxvt.keysym.End: \033[4~
585     URxvt.keysym.C-apostrophe: \033<C-'>
586     URxvt.keysym.C-slash: \033<C-/>
587     URxvt.keysym.C-semicolon: \033<C-;>
588     URxvt.keysym.C-grave: \033<C-`>
589     URxvt.keysym.C-comma: \033<C-,>
590     URxvt.keysym.C-period: \033<C-.>
591     URxvt.keysym.C-0x60: \033<C-`>
592     URxvt.keysym.C-Tab: \033<C-Tab>
593     URxvt.keysym.C-Return: \033<C-Return>
594     URxvt.keysym.S-Return: \033<S-Return>
595     URxvt.keysym.S-space: \033<S-Space>
596     URxvt.keysym.M-Up: \033<M-Up>
597     URxvt.keysym.M-Down: \033<M-Down>
598     URxvt.keysym.M-Left: \033<M-Left>
599     URxvt.keysym.M-Right: \033<M-Right>
600     URxvt.keysym.M-C-0: list \033<M-C- 0123456789 >
601     URxvt.keysym.M-C-a: list \033<M-C- abcdefghijklmnopqrstuvwxyz >
602     URxvt.keysym.F12: command:\033]701;zh_CN.GBK\007
603    
604     See some more examples in the documentation for the keysym resource.
605    
606     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
607     KP_Insert == Insert
608     F22 == Print
609     F27 == Home
610     F29 == Prior
611     F33 == End
612     F35 == Next
613    
614     Rather than have rxvt-unicode try to accommodate all the various
615     possible keyboard mappings, it is better to use `xmodmap' to remap the
616     keys as required for your particular machine.
617    
618     Terminal Configuration
619     Can I see a typical configuration?
620     The default configuration tries to be xterm-like, which I don't like
621     that much, but it's least surprise to regular users.
622    
623     As a rxvt or rxvt-unicode user, you are practically supposed to invest
624     time into customising your terminal. To get you started, here is the
625     author's .Xdefaults entries, with comments on what they do. It's
626     certainly not *typical*, but what's typical...
627    
628     URxvt.cutchars: "()*,<>[]{}|'
629     URxvt.print-pipe: cat >/tmp/xxx
630    
631     These are just for testing stuff.
632    
633     URxvt.imLocale: ja_JP.UTF-8
634     URxvt.preeditType: OnTheSpot,None
635    
636     This tells rxvt-unicode to use a special locale when communicating with
637     the X Input Method, and also tells it to only use the OnTheSpot pre-edit
638     type, which requires the "xim-onthespot" perl extension but rewards me
639     with correct-looking fonts.
640    
641     URxvt.perl-lib: /root/lib/urxvt
642     URxvt.perl-ext-common: default,selection-autotransform,selection-pastebin,xim-onthespot,remote-clipboard
643     URxvt.selection.pattern-0: ( at .*? line \\d+)
644     URxvt.selection.pattern-1: ^(/[^:]+):\
645     URxvt.selection-autotransform.0: s/^([^:[:space:]]+):(\\d+):?$/:e \\Q$1\\E\\x0d:$2\\x0d/
646     URxvt.selection-autotransform.1: s/^ at (.*?) line (\\d+)$/:e \\Q$1\\E\\x0d:$2\\x0d/
647    
648     This is my perl configuration. The first two set the perl library
649     directory and also tells urxvt to use a large number of extensions. I
650     develop for myself mostly, so I actually use most of the extensions I
651     write.
652    
653     The selection stuff mainly makes the selection perl-error-message aware
654 root 1.43 and tells it to convert perl error messages into vi-commands to load the
655 root 1.58 relevant file and go to the error line number.
656 root 1.42
657     URxvt.scrollstyle: plain
658     URxvt.secondaryScroll: true
659    
660     As the documentation says: plain is the preferred scrollbar for the
661 root 1.43 author. The "secondaryScroll" configures urxvt to scroll in full-screen
662     apps, like screen, so lines scrolled out of screen end up in urxvt's
663 root 1.42 scrollback buffer.
664    
665     URxvt.background: #000000
666     URxvt.foreground: gray90
667     URxvt.color7: gray90
668     URxvt.colorBD: #ffffff
669     URxvt.cursorColor: #e0e080
670     URxvt.throughColor: #8080f0
671     URxvt.highlightColor: #f0f0f0
672    
673     Some colours. Not sure which ones are being used or even non-defaults,
674     but these are in my .Xdefaults. Most notably, they set
675     foreground/background to light gray/black, and also make sure that the
676     colour 7 matches the default foreground colour.
677    
678     URxvt.underlineColor: yellow
679    
680     Another colour, makes underline lines look different. Sometimes hurts,
681     but is mostly a nice effect.
682    
683     URxvt.geometry: 154x36
684     URxvt.loginShell: false
685     URxvt.meta: ignore
686     URxvt.utmpInhibit: true
687    
688     Uh, well, should be mostly self-explanatory. By specifying some defaults
689     manually, I can quickly switch them for testing.
690    
691     URxvt.saveLines: 8192
692    
693     A large scrollback buffer is essential. Really.
694    
695     URxvt.mapAlert: true
696    
697     The only case I use it is for my IRC window, which I like to keep
698     iconified till people msg me (which beeps).
699    
700     URxvt.visualBell: true
701    
702     The audible bell is often annoying, especially when in a crowd.
703    
704     URxvt.insecure: true
705    
706     Please don't hack my mutt! Ooops...
707    
708     URxvt.pastableTabs: false
709    
710     I once thought this is a great idea.
711    
712     urxvt.font: 9x15bold,\
713     -misc-fixed-bold-r-normal--15-140-75-75-c-90-iso10646-1,\
714     -misc-fixed-medium-r-normal--15-140-75-75-c-90-iso10646-1, \
715     [codeset=JISX0208]xft:Kochi Gothic, \
716     xft:Bitstream Vera Sans Mono:autohint=true, \
717     xft:Code2000:antialias=false
718     urxvt.boldFont: -xos4-terminus-bold-r-normal--14-140-72-72-c-80-iso8859-15
719     urxvt.italicFont: xft:Bitstream Vera Sans Mono:italic:autohint=true
720     urxvt.boldItalicFont: xft:Bitstream Vera Sans Mono:bold:italic:autohint=true
721    
722     I wrote rxvt-unicode to be able to specify fonts exactly. So don't be
723 root 1.43 overwhelmed. A special note: the "9x15bold" mentioned above is actually
724 root 1.42 the version from XFree-3.3, as XFree-4 replaced it by a totally
725     different font (different glyphs for ";" and many other harmless
726     characters), while the second font is actually the "9x15bold" from
727     XFree4/XOrg. The bold version has less chars than the medium version, so
728 root 1.43 I use it for rare characters, too. When editing sources with vim, I use
729 root 1.42 italic for comments and other stuff, which looks quite good with
730     Bitstream Vera anti-aliased.
731    
732     Terminus is a quite bad font (many very wrong glyphs), but for most of
733     my purposes, it works, and gives a different look, as my normal
734     (Non-bold) font is already bold, and I want to see a difference between
735     bold and normal fonts.
736    
737     Please note that I used the "urxvt" instance name and not the "URxvt"
738 root 1.58 class name. That is because I use different configs for different
739 root 1.42 purposes, for example, my IRC window is started with "-name IRC", and
740     uses these defaults:
741    
742     IRC*title: IRC
743     IRC*geometry: 87x12+535+542
744     IRC*saveLines: 0
745     IRC*mapAlert: true
746     IRC*font: suxuseuro
747     IRC*boldFont: suxuseuro
748     IRC*colorBD: white
749     IRC*keysym.M-C-1: command:\033]710;suxuseuro\007\033]711;suxuseuro\007
750     IRC*keysym.M-C-2: command:\033]710;9x15bold\007\033]711;9x15bold\007
751    
752 root 1.57 "Alt-Ctrl-1" and "Alt-Ctrl-2" switch between two different font sizes.
753 root 1.42 "suxuseuro" allows me to keep an eye (and actually read) stuff while
754     keeping a very small window. If somebody pastes something complicated
755     (e.g. japanese), I temporarily switch to a larger font.
756    
757     The above is all in my ".Xdefaults" (I don't use ".Xresources" nor
758     "xrdb"). I also have some resources in a separate ".Xdefaults-hostname"
759     file for different hosts, for example, on ym main desktop, I use:
760    
761     URxvt.keysym.C-M-q: command:\033[3;5;5t
762     URxvt.keysym.C-M-y: command:\033[3;5;606t
763     URxvt.keysym.C-M-e: command:\033[3;1605;5t
764     URxvt.keysym.C-M-c: command:\033[3;1605;606t
765     URxvt.keysym.C-M-p: perl:test
766    
767     The first for keysym definitions allow me to quickly bring some windows
768     in the layout I like most. Ion users might start laughing but will stop
769     immediately when I tell them that I use my own Fvwm2 module for much the
770     same effect as Ion provides, and I only very rarely use the above key
771     combinations :->
772    
773     Why doesn't rxvt-unicode read my resources?
774     Well, why, indeed? It does, in a way very similar to other X
775     applications. Most importantly, this means that if you or your OS loads
776     resources into the X display (the right way to do it), rxvt-unicode will
777     ignore any resource files in your home directory. It will only read
778     $HOME/.Xdefaults when no resources are attached to the display.
779    
780     If you have or use an $HOME/.Xresources file, chances are that resources
781     are loaded into your X-server. In this case, you have to re-login after
782     every change (or run xrdb -merge $HOME/.Xresources).
783    
784     Also consider the form resources have to use:
785    
786     URxvt.resource: value
787    
788     If you want to use another form (there are lots of different ways of
789 root 1.43 specifying resources), make sure you understand whether and why it
790     works. If unsure, use the form above.
791 root 1.42
792     When I log-in to another system it tells me about missing terminfo data?
793     The terminal description used by rxvt-unicode is not as widely available
794     as that for xterm, or even rxvt (for which the same problem often
795     arises).
796    
797     The correct solution for this problem is to install the terminfo, this
798 root 1.57 can be done by simply installing rxvt-unicode on the remote system as
799     well (in case you have a nice package manager ready), or you can install
800     the terminfo database manually like this (with ncurses infocmp. works as
801     user and root):
802 root 1.42
803     REMOTE=remotesystem.domain
804 root 1.44 infocmp rxvt-unicode | ssh $REMOTE "mkdir -p .terminfo && cat >/tmp/ti && tic /tmp/ti"
805 root 1.42
806 root 1.44 One some systems you might need to set $TERMINFO to the full path of
807     $HOME/.terminfo for this to work.
808    
809 root 1.42 If you cannot or do not want to do this, then you can simply set
810     "TERM=rxvt" or even "TERM=xterm", and live with the small number of
811     problems arising, which includes wrong keymapping, less and different
812     colours and some refresh errors in fullscreen applications. It's a nice
813     quick-and-dirty workaround for rare cases, though.
814    
815     If you always want to do this (and are fine with the consequences) you
816     can either recompile rxvt-unicode with the desired TERM value or use a
817     resource to set it:
818    
819     URxvt.termName: rxvt
820    
821     If you don't plan to use rxvt (quite common...) you could also replace
822     the rxvt terminfo file with the rxvt-unicode one and use "TERM=rxvt".
823    
824 root 1.57 nano fails with "Error opening terminal: rxvt-unicode"
825     This exceptionally confusing and useless error message is printed by
826     nano when it can't find the terminfo database. Nothing is wrong with
827     your terminal, read the previous answer for a solution.
828    
829 root 1.42 "tic" outputs some error when compiling the terminfo entry.
830     Most likely it's the empty definition for "enacs=". Just replace it by
831     "enacs=\E[0@" and try again.
832    
833     "bash"'s readline does not work correctly under urxvt.
834     See next entry.
835    
836     I need a termcap file entry.
837     One reason you might want this is that some distributions or operating
838     systems still compile some programs using the long-obsoleted termcap
839     library (Fedora Core's bash is one example) and rely on a termcap entry
840     for "rxvt-unicode".
841    
842 root 1.43 You could use rxvt's termcap entry with reasonable results in many
843     cases. You can also create a termcap entry by using terminfo's infocmp
844     program like this:
845 root 1.42
846     infocmp -C rxvt-unicode
847    
848 root 1.55 Or you could use the termcap entry in doc/etc/rxvt-unicode.termcap,
849     generated by the command above.
850 root 1.42
851     Why does "ls" no longer have coloured output?
852     The "ls" in the GNU coreutils unfortunately doesn't use terminfo to
853 root 1.43 decide whether a terminal has colour, but uses its own configuration
854 root 1.42 file. Needless to say, "rxvt-unicode" is not in its default file (among
855     with most other terminals supporting colour). Either add:
856    
857     TERM rxvt-unicode
858    
859     to "/etc/DIR_COLORS" or simply add:
860    
861     alias ls='ls --color=auto'
862    
863     to your ".profile" or ".bashrc".
864    
865     Why doesn't vim/emacs etc. use the 88 colour mode?
866     See next entry.
867    
868     Why doesn't vim/emacs etc. make use of italic?
869     See next entry.
870    
871     Why are the secondary screen-related options not working properly?
872     Make sure you are using "TERM=rxvt-unicode". Some pre-packaged
873     distributions (most notably Debian GNU/Linux) break rxvt-unicode by
874     setting "TERM" to "rxvt", which doesn't have these extra features.
875     Unfortunately, some of these (most notably, again, Debian GNU/Linux)
876     furthermore fail to even install the "rxvt-unicode" terminfo file, so
877     you will need to install it on your own (See the question When I log-in
878     to another system it tells me about missing terminfo data? on how to do
879     this).
880    
881     Encoding / Locale / Input Method Issues
882     Rxvt-unicode does not seem to understand the selected encoding?
883     See next entry.
884    
885     Unicode does not seem to work?
886     If you encounter strange problems like typing an accented character but
887     getting two unrelated other characters or similar, or if program output
888     is subtly garbled, then you should check your locale settings.
889    
890     Rxvt-unicode must be started with the same "LC_CTYPE" setting as the
891 root 1.46 programs running in it. Often rxvt-unicode is started in the "C" locale,
892     while the login script running within the rxvt-unicode window changes
893     the locale to something else, e.g. "en_GB.UTF-8". Needless to say, this
894     is not going to work, and is the most common cause for problems.
895 root 1.42
896     The best thing is to fix your startup environment, as you will likely
897     run into other problems. If nothing works you can try this in your
898     .profile.
899    
900 root 1.46 printf '\33]701;%s\007' "$LC_CTYPE" # $LANG or $LC_ALL are worth a try, too
901 root 1.42
902     If this doesn't work, then maybe you use a "LC_CTYPE" specification not
903     supported on your systems. Some systems have a "locale" command which
904     displays this (also, "perl -e0" can be used to check locale settings, as
905     it will complain loudly if it cannot set the locale). If it displays
906     something like:
907    
908     locale: Cannot set LC_CTYPE to default locale: ...
909    
910     Then the locale you specified is not supported on your system.
911    
912     If nothing works and you are sure that everything is set correctly then
913     you will need to remember a little known fact: Some programs just don't
914     support locales :(
915    
916     How does rxvt-unicode determine the encoding to use?
917     See next entry.
918    
919     Is there an option to switch encodings?
920     Unlike some other terminals, rxvt-unicode has no encoding switch, and no
921     specific "utf-8" mode, such as xterm. In fact, it doesn't even know
922     about UTF-8 or any other encodings with respect to terminal I/O.
923    
924     The reasons is that there exists a perfectly fine mechanism for
925     selecting the encoding, doing I/O and (most important) communicating
926     this to all applications so everybody agrees on character properties
927     such as width and code number. This mechanism is the *locale*.
928     Applications not using that info will have problems (for example,
929     "xterm" gets the width of characters wrong as it uses its own,
930     locale-independent table under all locales).
931    
932     Rxvt-unicode uses the "LC_CTYPE" locale category to select encoding. All
933     programs doing the same (that is, most) will automatically agree in the
934     interpretation of characters.
935    
936     Unfortunately, there is no system-independent way to select locales, nor
937     is there a standard on how locale specifiers will look like.
938    
939     On most systems, the content of the "LC_CTYPE" environment variable
940     contains an arbitrary string which corresponds to an already-installed
941     locale. Common names for locales are "en_US.UTF-8", "de_DE.ISO-8859-15",
942     "ja_JP.EUC-JP", i.e. "language_country.encoding", but other forms (i.e.
943     "de" or "german") are also common.
944    
945     Rxvt-unicode ignores all other locale categories, and except for the
946     encoding, ignores country or language-specific settings, i.e.
947     "de_DE.UTF-8" and "ja_JP.UTF-8" are the normally same to rxvt-unicode.
948    
949     If you want to use a specific encoding you have to make sure you start
950     rxvt-unicode with the correct "LC_CTYPE" category.
951    
952     Can I switch locales at runtime?
953     Yes, using an escape sequence. Try something like this, which sets
954     rxvt-unicode's idea of "LC_CTYPE".
955    
956     printf '\33]701;%s\007' ja_JP.SJIS
957    
958     See also the previous answer.
959    
960     Sometimes this capability is rather handy when you want to work in one
961     locale (e.g. "de_DE.UTF-8") but some programs don't support it (e.g.
962     UTF-8). For example, I use this script to start "xjdic", which first
963     switches to a locale supported by xjdic and back later:
964    
965     printf '\33]701;%s\007' ja_JP.SJIS
966     xjdic -js
967     printf '\33]701;%s\007' de_DE.UTF-8
968    
969     You can also use xterm's "luit" program, which usually works fine,
970     except for some locales where character width differs between program-
971     and rxvt-unicode-locales.
972    
973     I have problems getting my input method working.
974     Try a search engine, as this is slightly different for every input
975     method server.
976    
977     Here is a checklist:
978    
979     - Make sure your locale *and* the imLocale are supported on your OS.
980     Try "locale -a" or check the documentation for your OS.
981    
982     - Make sure your locale or imLocale matches a locale supported by your
983     XIM.
984     For example, kinput2 does not support UTF-8 locales, you should use
985     "ja_JP.EUC-JP" or equivalent.
986    
987     - Make sure your XIM server is actually running.
988     - Make sure the "XMODIFIERS" environment variable is set correctly when
989     *starting* rxvt-unicode.
990     When you want to use e.g. kinput2, it must be set to "@im=kinput2".
991 root 1.43 For scim, use "@im=SCIM". You can see what input method servers are
992 root 1.42 running with this command:
993    
994     xprop -root XIM_SERVERS
995    
996 root 1.54
997 root 1.42
998     My input method wants <some encoding> but I want UTF-8, what can I do?
999     You can specify separate locales for the input method and the rest of
1000     the terminal, using the resource "imlocale":
1001    
1002     URxvt.imlocale: ja_JP.EUC-JP
1003    
1004     Now you can start your terminal with "LC_CTYPE=ja_JP.UTF-8" and still
1005     use your input method. Please note, however, that, depending on your
1006     Xlib version, you may not be able to input characters outside "EUC-JP"
1007     in a normal way then, as your input method limits you.
1008    
1009     Rxvt-unicode crashes when the X Input Method changes or exits.
1010     Unfortunately, this is unavoidable, as the XIM protocol is racy by
1011     design. Applications can avoid some crashes at the expense of memory
1012     leaks, and Input Methods can avoid some crashes by careful ordering at
1013     exit time. kinput2 (and derived input methods) generally succeeds, while
1014     SCIM (or similar input methods) fails. In the end, however, crashes
1015     cannot be completely avoided even if both sides cooperate.
1016    
1017     So the only workaround is not to kill your Input Method Servers.
1018    
1019     Operating Systems / Package Maintaining
1020     I am using Debian GNU/Linux and have a problem...
1021     The Debian GNU/Linux package of rxvt-unicode in sarge contains large
1022     patches that considerably change the behaviour of rxvt-unicode (but
1023     unfortunately this notice has been removed). Before reporting a bug to
1024     the original rxvt-unicode author please download and install the genuine
1025     version (<http://software.schmorp.de#rxvt-unicode>) and try to reproduce
1026     the problem. If you cannot, chances are that the problems are specific
1027     to Debian GNU/Linux, in which case it should be reported via the Debian
1028     Bug Tracking System (use "reportbug" to report the bug).
1029    
1030     For other problems that also affect the Debian package, you can and
1031     probably should use the Debian BTS, too, because, after all, it's also a
1032     bug in the Debian version and it serves as a reminder for other users
1033     that might encounter the same issue.
1034    
1035     I am maintaining rxvt-unicode for distribution/OS XXX, any recommendation?
1036     You should build one binary with the default options. configure now
1037     enables most useful options, and the trend goes to making them
1038 root 1.43 runtime-switchable, too, so there is usually no drawback to enabling
1039 root 1.42 them, except higher disk and possibly memory usage. The perl interpreter
1040     should be enabled, as important functionality (menus, selection, likely
1041     more in the future) depends on it.
1042    
1043 root 1.58 You should not overwrite the "perl-ext-common" and "perl-ext" resources
1044 root 1.42 system-wide (except maybe with "defaults"). This will result in useful
1045     behaviour. If your distribution aims at low memory, add an empty
1046     "perl-ext-common" resource to the app-defaults file. This will keep the
1047     perl interpreter disabled until the user enables it.
1048    
1049     If you can/want build more binaries, I recommend building a minimal one
1050     with "--disable-everything" (very useful) and a maximal one with
1051     "--enable-everything" (less useful, it will be very big due to a lot of
1052     encodings built-in that increase download times and are rarely used).
1053    
1054     I need to make it setuid/setgid to support utmp/ptys on my OS, is this safe?
1055     It should be, starting with release 7.1. You are encouraged to properly
1056     install urxvt with privileges necessary for your OS now.
1057    
1058     When rxvt-unicode detects that it runs setuid or setgid, it will fork
1059     into a helper process for privileged operations (pty handling on some
1060     systems, utmp/wtmp/lastlog handling on others) and drop privileges
1061     immediately. This is much safer than most other terminals that keep
1062     privileges while running (but is more relevant to urxvt, as it contains
1063     things as perl interpreters, which might be "helpful" to attackers).
1064    
1065     This forking is done as the very first within main(), which is very
1066     early and reduces possible bugs to initialisation code run before
1067     main(), or things like the dynamic loader of your system, which should
1068     result in very little risk.
1069    
1070     I am on FreeBSD and rxvt-unicode does not seem to work at all.
1071     Rxvt-unicode requires the symbol "__STDC_ISO_10646__" to be defined in
1072     your compile environment, or an implementation that implements it,
1073 root 1.43 whether it defines the symbol or not. "__STDC_ISO_10646__" requires that
1074 root 1.42 wchar_t is represented as unicode.
1075    
1076 root 1.43 As you might have guessed, FreeBSD does neither define this symbol nor
1077 root 1.42 does it support it. Instead, it uses its own internal representation of
1078     wchar_t. This is, of course, completely fine with respect to standards.
1079    
1080     However, that means rxvt-unicode only works in "POSIX", "ISO-8859-1" and
1081 root 1.55 "UTF-8" locales under FreeBSD (which all use Unicode as wchar_t).
1082 root 1.42
1083     "__STDC_ISO_10646__" is the only sane way to support multi-language apps
1084     in an OS, as using a locale-dependent (and non-standardized)
1085     representation of wchar_t makes it impossible to convert between wchar_t
1086     (as used by X11 and your applications) and any other encoding without
1087     implementing OS-specific-wrappers for each and every locale. There
1088     simply are no APIs to convert wchar_t into anything except the current
1089     locale encoding.
1090    
1091     Some applications (such as the formidable mlterm) work around this by
1092     carrying their own replacement functions for character set handling with
1093     them, and either implementing OS-dependent hacks or doing multiple
1094     conversions (which is slow and unreliable in case the OS implements
1095     encodings slightly different than the terminal emulator).
1096    
1097     The rxvt-unicode author insists that the right way to fix this is in the
1098     system libraries once and for all, instead of forcing every app to carry
1099     complete replacements for them :)
1100    
1101     How can I use rxvt-unicode under cygwin?
1102     rxvt-unicode should compile and run out of the box on cygwin, using the
1103     X11 libraries that come with cygwin. libW11 emulation is no longer
1104     supported (and makes no sense, either, as it only supported a single
1105     font). I recommend starting the X-server in "-multiwindow" or
1106     "-rootless" mode instead, which will result in similar look&feel as the
1107     old libW11 emulation.
1108    
1109     At the time of this writing, cygwin didn't seem to support any
1110     multi-byte encodings (you might try "LC_CTYPE=C-UTF-8"), so you are
1111     likely limited to 8-bit encodings.
1112    
1113 root 1.49 Character widths are not correct.
1114     urxvt uses the system wcwidth function to know the information about the
1115     width of characters, so on systems with incorrect locale data you will
1116     likely get bad results. Two notorious examples are Solaris 9, where
1117     single-width characters like U+2514 are reported as double-width, and
1118     Darwin 8, where combining chars are reported having width 1.
1119    
1120     The solution is to upgrade your system or switch to a better one. A
1121     possibly working workaround is to use a wcwidth implementation like
1122    
1123     http://www.cl.cam.ac.uk/~mgk25/ucs/wcwidth.c
1124    
1125 root 1.57 I want 256 colors
1126     Are you sure you need 256 colors? 88 colors should be enough for most
1127     purposes. If you really need more, there is an unsupported patch for it
1128     in the doc directory, but please do not ask for it to be applied.
1129