bug#37363: emacs and other programs do not display special characters

[Bengt Richter]

On +2019-09-09 19:13:08 -0500, address@hidden wrote:
> As per nckx's question on IRC, this is the output to locale on both Emacs
> shell and BASh:
> 
> quiliro@GSD3 ~/magit/prueba0$ locale
> LANG=es_EC.UTF-8
> LC_CTYPE="es_EC.UTF-8"
> LC_NUMERIC="es_EC.UTF-8"
> LC_TIME="es_EC.UTF-8"
> LC_COLLATE="es_EC.UTF-8"
> LC_MONETARY="es_EC.UTF-8"
> LC_MESSAGES="es_EC.UTF-8"
> LC_PAPER="es_EC.UTF-8"
> LC_NAME="es_EC.UTF-8"
> LC_ADDRESS="es_EC.UTF-8"
> LC_TELEPHONE="es_EC.UTF-8"
> LC_MEASUREMENT="es_EC.UTF-8"
> LC_IDENTIFICATION="es_EC.UTF-8"
> LC_ALL=
> 
> 
Hi,
I have been having locale-related problems too,
so maybe we can bounce enough clues around that
we can advance a little.

[ later ... I'll have to come back to locale per se,
  but hope the following is useful for poking around
  with fonts and unicode character and their glyphs ]

[ To the advanced, please don't be insulted by my posting
  obvious stuff, as if you didn't know how to use grep and sed
  and especially guix better than my examples show --
  it is motivated by wanting to exchange helpful methods and info
  with others also coming to guix, who might benefit from my recent
  newbie experiences trying to find my way into guix city, in the
  Commonwealth of FOSS :)

  Hm, I wonder if we could use postgresql plus postgis to do
  an openstreetmap map of guix city stores and pubs
  -- and potholes and contruction blockages ;-)
]
  
Anyway, I have a little script which may be helpful
in generating utf8 characters for display in your
various contexts (what this (emacs) context is I'll show below):

$ uchr 229 10
å
$ which -a uchr
/home/bokr/bin/uchr
$ cat ~/bin/uchr
#!/home/bokr/.guix-profile/bin/bash
# 2019-08-19 22:25:34 ## was: #!/usr/bin/bash
# ~/bin/uchr -- print unicode characters from numeric args
# uchr 65 67 10 | od -a -t x1
# 0000000   A   C  nl
#          41  43  0a
# 0000003
cc="$( printf '\\u%x' "$@" )"
echo -en "$cc"

Those last two lines do all the work ;-)
(printf is a bash built-in -- type -"help printf"
at the bash command line.

(By -"foo" I mean "foo" minus the quotes :)

printf re-uses its format for each arg it encounters, so it
converts all the integers according to '\\u%x' above in uchr.

$ uchr {192..255} 10
ÀÁÂÃÄÅÆÇÈÉÊËÌÍÎÏÐÑÒÓÔÕÖ×ØÙÚÛÜÝÞßàáâãäåæçèéêëìíîïðñòóôõö÷øùúûüýþÿ
$
What do you get if you try that from your login console, not gnome?

To make various fonts available to the console, you should be
able to use setfont from console bash -- see -"man setfont"
(remembering my minus-the-quotes notation :)

The {FIRST_INTEGER..LAST_INTEGER} of course generates individual
integer arguments including first and last. The 10 is a newline.

I'm pretty sure I did -"setfont sun12x22" from the console bash,
which gives you most of the 12x22 font built into the kernel.

It's got 256 character cells for its 12x22 pixel glyphs, each
represented by 22 16-bit integers using the ms12 bits with 1
as foreground, IIRC.

The sun12x22 font is pretty good, with box-drawing characters
as well most things you need in European languages (I'm familiar
with it because I wrote a little script to display the glyphs
on the frame buffer, in the pursuit of independence from huge
blobs of gooey GUI software :)

After having done -"setfont sun12x22" you can do
-"setfont -ou glyph-code-to-unicodepoint.txt" which will
give you a tab-delimited table starting ... ending like:

0x00    U+0000
0x20    U+0020
0x21    U+0021
0x22    U+0022
0x23    U+0023
0x24    U+0024
0x25    U+0025
...
0xdf    U+2580
0xdc    U+2584
0xdb    U+2588
0xdd    U+258c
0xde    U+2590
0xb0    U+2591
0xb1    U+2592
0xb2    U+2593
0x01    U+263a
0x5f    U+f804

(BTW, this would be really easy to snarf and convert to
an assoc list mapping unicode code points to glyph indices)

That glyph 0x01 has a unicode we can discover, even though
the console font you get from -"setfont sun12x22" does not
have the glyph that is in the kernel version's glyph table:

$ 
$ unicode-info "$(uchr 0x263a)"

"☺":
    glyph  codepoint .....int  name...
    _☺_     +U00263a     9786  WHITE SMILING FACE  
$ 

The glyph is in the kernel's 256-glyph bit-map for
sun12x22 though, and it should be visible in a gui browser
with good unicode coverage.

You can find the kernel's bitfont defined in kernel sources
.../linux-4.14.3/lib/fonts/font_sun12x22.c (or change
the kernel version -- 4.14.3 is the last one I grop^H^Hepped around in
looking for stuff to "steal" :)

Ok, back to
$ uchr {192..255} 10
ÀÁÂÃÄÅÆÇÈÉÊËÌÍÎÏÐÑÒÓÔÕÖ×ØÙÚÛÜÝÞßàáâãäåæçèéêëìíîïðñòóôõö÷øùúûüýþÿ
$

The first four A's above are really not As, as another little script
of mine that shows unicode information will show:

(you can find the source archived in a recent post of mine
    https://lists.gnu.org/archive/html/guix-devel/2019-09/msg00115.html
if curious)

$ uchr {192..202} | unicode-info

"ÀÁÂÃÄÅÆÇÈÉÊ":
    glyph  codepoint .....int  name...
    _À_     +U0000c0      192  LATIN CAPITAL LETTER A WITH GRAVE  
    _Á_     +U0000c1      193  LATIN CAPITAL LETTER A WITH ACUTE  
    _Â_     +U0000c2      194  LATIN CAPITAL LETTER A WITH CIRCUMFLEX  
    _Ã_     +U0000c3      195  LATIN CAPITAL LETTER A WITH TILDE  
    _Ä_     +U0000c4      196  LATIN CAPITAL LETTER A WITH DIAERESIS  
    _Å_     +U0000c5      197  LATIN CAPITAL LETTER A WITH RING ABOVE  
    _Æ_     +U0000c6      198  LATIN CAPITAL LETTER AE  
    _Ç_     +U0000c7      199  LATIN CAPITAL LETTER C WITH CEDILLA  
    _È_     +U0000c8      200  LATIN CAPITAL LETTER E WITH GRAVE  
    _É_     +U0000c9      201  LATIN CAPITAL LETTER E WITH ACUTE  
    _Ê_     +U0000ca      202  LATIN CAPITAL LETTER E WITH CIRCUMFLEX  
$ 

The above is copy/pasted from a shell window I got by -"M-x shell"
To show the pid genealogy of that shell context, I'll -"C-x o"
over there and output about the context and paste it back here:

$ 
$ # typing pidgeny (for pid genealogy :) we get:
$ pidgeny
pidgeny         pts/0    23549 S+   /home/bokr/.guix-profile/bin/bash /home/bokr
bash            pts/0    16231 Ss   /home/bokr/.guix-profile/bin/bash --noeditin
.emacs-26.3-rea tty1     16204 Sl+  /gnu/store/ki85c221k56y6hnp7qyx42q2qmra4w4s-
mutt            tty1      1118 S    mutt
bash            tty1       537 Ss   -bash
login           ?          521 Ss   login -- bokr
systemd         ?            1 Ss   /sbin/init \EFI\PhantoNv4ArchGx\vmlinuz-linu
$ which pidgeny|xargs realpath
/home/bokr/bin/pidgeny
$ ## --- pidgeny ---
$ which pidgeny|xargs cat
#!/home/bokr/.guix-profile/bin/bash
# 2019-08-19 07:16:38 -- was: #!/usr/bin/bash
# ~/bin/pidgeny

pid=${1:-$$}    #this process if no pid specified as $1

while [ $(($pid)) -gt 0 ]; do    
      ps h -p $pid -o comm,tt,pid,stat,args
      pid=$(ps -q $pid -o ppid=)
done
$ ## hm, monkeyed with that hashbang too, need a better idea :)
$ 
$ ## pidgeny output doesn't show full path on mutt 1118,bash 537,
$ ## or login 521, but we can get them easily:
$ realpath /proc/1118/exe
/gnu/store/bsd34k2v78mi0wxk85rz32xaminls9nb-mutt-1.12.1/bin/mutt
$ ## that was a guix version
$ realpath /proc/537/exe
/usr/bin/bash
$ ## that was the inital shell of the "foreign distro" -- in my case:
$ uname -a
Linux PhantoNv4ArchGx 5.2.9-arch1-1-ARCH #1 SMP PREEMPT Fri Aug 16 11:29:43 UTC 
2019 x86_64 GNU/Linux
$ realpath /proc/521/exe
realpath: /proc/521/exe: Permission denied
$ ## need permission
$ su -c 'realpath /proc/521/exe'
/usr/bin/login
$ ## also built by the foreign distro's building tool chain
  and libraries -- I guess I will feel better
$ ## when I replace the foreigner with linux-libre ;-)
$ 

Well, HTH you to probe the state of your system vis-a-vis
utf8, glyphs, fonts etc.

I'll come back with some locale mystery, which will probably
wind up being something I thought I did but didn't ;-/

But now I need to go do some things IRL ;-)

Regards,
Bengt Richter