Localization is an undocumented Bash feature.
A localized shell script echoes its text output in the
language defined as the system's locale. A Linux user in Berlin,
Germany, would get script output in German, whereas his cousin
in Berlin, Maryland, would get output from the same script in
English.
To create a localized script, use the following template to
write all messages to the user (error messages, prompts,
etc.).
#!/bin/bash
# localized.sh
E_CDERROR=65
error()
{
printf "$@" >&2
exit $E_CDERROR
}
cd $var || error $"Can't cd to %s." "$var"
read -p $"Enter the value: " var
# ... |
bash$ bash -D localized.sh
"Can't cd to %s."
"Enter the value: " |
This lists all the localized text. (The
-D
option lists double-quoted strings prefixed by a
$,
without executing the script.)
bash$ bash --dump-po-strings localized.sh
#: a:6
msgid "Can't cd to %s."
msgstr ""
#: a:7
msgid "Enter the value: "
msgstr "" |
The
--dump-po-strings option to Bash
resembles the
-D option, but uses
gettext "po" format.
Now, build a language.po
file for each language that the script will be translated
into, specifying the msgstr. As an
example:
fr.po:
#: a:6
msgid "Can't cd to %s."
msgstr "Impossible de se positionner dans le répertoire %s."
#: a:7
msgid "Enter the value: "
msgstr "Entrez la valeur : " |
Then, run msgfmt.
msgfmt -o localized.sh.mo fr.po
Place the resulting localized.sh.mo file in the
/usr/local/share/locale/fr/LC_MESSAGES
directory, and at the beginning of the script, insert the lines:
TEXTDOMAINDIR=/usr/local/share/locale
TEXTDOMAIN=localized.sh |
If a user on a French system runs the script, she will get
French messages.
| With older versions of Bash or other shells, localization requires
gettext, using the
-s option. In this case, the script becomes:
#!/bin/bash
# localized.sh
E_CDERROR=65
error() {
local format=$1
shift
printf "$(gettext -s "$format")" "$@" >&2
exit $E_CDERROR
}
cd $var || error "Can't cd to %s." "$var"
read -p "$(gettext -s "Enter the value: ")" var
# ... |
|
The TEXTDOMAIN and
TEXTDOMAINDIR variables need to be exported
to the environment.
---
This appendix written by Stephane Chazelas.
