The Linux keyboard and console HOWTO: How to make other programs work with non-ASCII chars

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## 12. How to make other programs work with non-ASCII chars

In the bad old days this used to be quite a hassle. Every separate program had to be convinced individually to leave your bits alone. Not that all is easy now, but recently a lot of gnu utilities have learned to react to `LC_CTYPE=iso_8859_1` or `LC_CTYPE=iso-8859-1`. Try this first, and if it doesn't help look at the hints below. Note that in recent versions of libc the routine setlocale() only works if you have installed the locale files (e.g. in `/usr/lib/locale`).

First of all, the 8-th bit should survive the kernel input processing, so make sure to have `stty cs8 -istrip -parenb` set.

A. For `emacs` the details strongly depend on the version. The information below is for version 19.34. Put lines

> `

>             (set-input-mode nil nil 1)
>             (standard-display-european t)
>             (require 'iso-syntax)

> `

into your `$HOME/.emacs`. The first line (to be precise: the final 1) tells `emacs` not to discard the 8-th bit from input characters. The second line tells `emacs` not to display non-ASCII characters as octal escapes. The third line specifies the syntactic properties and case conversion table for the Latin-1 character set These last two lines are superfluous if you have something like `LC_CTYPE=ISO-8859-1` in your environment. (The variable may also be `LC_ALL` or even `LANG`. The value may be anything with a substring `88591' or `8859-1' or `8859_1'.)

This is a good start. On a terminal that cannot display non-ASCII ISO 8859-1 symbols, the command

> `

>             (load-library "iso-ascii")

> `

will cause accented characters to be displayed comme {,c}a. If your keymap does not make it easy to produce non-ASCII characters, then

> `

>             (load-library "iso-transl")

> `

will make the 2-character sequence Ctrl-X 8 a compose character, so that the 4-character sequence Ctrl-X 8 , c produces c-cedilla. Very inconvenient.

The command

> `

>             (iso-accents-mode)

> `

will toggle ISO-8859-1 accent mode, in which the six characters ', `, ", ^, ~, / are dead keys modifying the following symbol. Special combinations: ~c gives a c with cedilla, ~d gives an Icelandic eth, ~t gives an Icelandic thorn, "s gives German sharp s, /a gives a with ring, /e gives an a-e ligature, ~< and ~> give guillemots, ~! gives an inverted exclamation mark, ~? gives an inverted question mark, and '' gives an acute accent. This is the default mapping of accents. The variable `iso-languages` is a list of pairs (language name, accent mapping), and a non-default mapping can be selected using

> `

>             (iso-accents-customize LANGUAGE)

> `

Here LANGUAGE can be one of `"portuguese"`, `"irish"`, `"french"`, `"latin-2"`, `"latin-1"`.

Since the Linux default compose character is Ctrl-. it might be convenient to use that everywhere. Try

> `

>             (load-library "iso-insert.el")
>             (define-key global-map [?\C-.] 8859-1-map)

> `

The latter line will not work under `xterm`, if you use `emacs -nw`, but in that case you can put

> `

>             XTerm*VT100.Translations:       #override\n\
>                   Ctrl <KeyPress> . : string("\0308")

> `

in your `.Xresources`.)

B. For `less`, put `LESSCHARSET=latin1` in the environment. This is also what you need if you see `\255` or `<AD>` in `man` output: some versions of `less` will render the soft hyphen (octal 0255, hex 0xAD) this way when not given permission to output Latin-1.

C. For `ls`, give the option `-N`. (Probably you want to make an alias.)

D. For `bash` (version 1.13.*), put

> `

>             set meta-flag on
>             set convert-meta off
>             set output-meta on

> `

into your `$HOME/.inputrc`.

E. For `tcsh`, use

> `

>             setenv LANG     US_en
>             setenv LC_CTYPE iso_8859_1

> `

If you have nls on your system, then the corresponding routines are used. Otherwise `tcsh` will assume iso_8859_1, regardless of the values given to LANG and LC_CTYPE. See the section NATIVE LANGUAGE SYSTEM in tcsh(1). (The Danish HOWTO says: `setenv LC_CTYPE ISO-8859-1; stty pass8`)

F. For `flex`, give the option `-8` if the parser it generates must be able to handle 8-bit input. (Of course it must.)

G. For `elm`, set `displaycharset` to `ISO-8859-1`. (Danish HOWTO: `LANG=C` and `LC_CTYPE=ISO-8859-1`)

H. For programs using curses (such as `lynx`) David Sibley reports: The regular curses package uses the high-order bit for reverse video mode (see flag _STANDOUT defined in `/usr/include/curses.h`). However, `ncurses` seems to be 8-bit clean and does display iso-latin-8859-1 correctly.

I. For programs using `groff` (such as `man`), make sure to use `-Tlatin1` instead of `-Tascii`. Old versions of the program `man` also use `col`, and the next point also applies.

J. For `col`, make sure 1) that it is fixed so as to do `setlocale(LC_CTYPE,"");` and 2) put `LC_CTYPE=ISO-8859-1` in the environment.

K. For `rlogin`, use option `-8`.

L. For `joe`, `metalab.unc.edu:/pub/Linux/apps/editors/joe-1.0.8-linux.tar.gz` is said to work after editing the configuration file. Someone else said: `joe`: Put the `-asis` option in `/isr/lib/joerc` in the first column.

M. For LaTeX: `\documentstyle[isolatin]{article}`. For LaTeX2e: `\documentclass{article}\usepackage{isolatin}` where `isolatin.sty` is available from ftp.vlsivie.tuwien.ac.at/pub/8bit.

A nice discussion on the topic of ISO-8859-1 and how to manage 8-bit characters is contained in the file `grasp.insa-lyon.fr:/pub/faq/fr/accents` (in French). Another fine discussion (in English) can be found in rtfm.mit.edu:pub/usenet-by-group/comp.answers/internationalization/iso-8859-1-charset.

If you need to fix a program that behaves badly with 8-bit characters, one thing to keep in mind is that if you have a signed char type then characters may be negative, and using them as an array index will fail. Several programs can be fixed by judiciously adding (unsigned char) casts.

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