Note that msgcat 1.3 (comes with Tcl 8.4) also initializes the locale from ::env(LC_ALL) or ::env(LC_MESSAGES).

LES: I don't have ::env(LC_ALL) and ::env(LC_MESSAGES) on Slackware 11.

Arjen Markus This came up in the newsgroup:

The utility frink is able to adjust the source code so that the new code uses the msgcat package.

The 8.3.4 release of the PPC binary is broken in that it lacks msgcat and bgerror implementations. Melissa Schrumpf explains the situation with her customary clarity

    ... bgerror and msgcat are contained in tcl/library/msgcat/msgcat.tcl.

    Do this:

    Copy "Simply Tk (PPC)" to "Simply Tk (PPC).edit"

    Run ResEdit (or Resourcer, or whathaveyou).  Open a "Simply Tk
    (PPC).edit" in ResEdit.  Open the "TEXT" resources.  Open resource ID
       "package require msgcat"

    This will be right at the top.

    Next, open tcl/library/msgcat/msgcat.tcl in a text editor.  Copy from
    the beginning of the line:

       package provide msgcat 1.1.1  




    through to the end of the file.

    Return to ResEdit.  Delete the line "package require msgcat" and,
    in its place, paste the code you copied from msgcat.tcl.
    Close all resources and save.

    You now have a fixed stand-alone Tk shell.      

Anton Kovalenko has written, "Also, there is a small but useful script, which converts non-ascii characters from current system encoding to \uXXXX sequences. I think it would be useful to anyone who works often with tcl message catalogs. http://kovalenko.webzone.ru/unicodize.tcl (A/AK: chat.ru is down, so my page migrated) "

LES: "Forbidden. You don't have permission to access /unicodize.tcl on this server."

A/AK: there are some things about msgcat and shortcut keys, that are important for GUI application writers. EKB And this seems to have been continued into ampersand magic.

KHM Any Idea where to download this tool?

LV KHM - msgcat is a part of Tcl itself. Or are you talking about some other tool?

GNU gettext has support (since V 0.13 [L1 ]) for Tcl msgcat and conversion tools from and to PO format. http://ftp.gnu.org/gnu/gettext/

Simple Tk example of switching languages, complements of dgp:

 package require Tk

 bgerror 123

 msgcat::mclocale "fr"
 msgcat::mcload [file join $::tk_library msgs]
 bgerror 123
 
 msgcat::mclocale "en_gb"
 msgcat::mcload [file join $::tk_library msgs]
 bgerror 123

Now, how can I determine what languages are available for mclocale?

escargo 8 Dec 2003 - What if you want to do some form of parameter substitution in the strings that you might use with msgcat? In some systems I have developed, messages were somewhat macro-like; you might pass a number or a name (of a file, for example) that should be part of the message. Is there anything in the msgcat that does the substitution internally, or do I have to add my own layer on top of it?

RS: Easy, for instance with format:

 msgcat::mcset fr "Directory contains %d files" "Il y a %d fichiers"
 ...
 puts [format [mc "Directory contains %d files"] $nfiles]

DGP Even easier. There's a format already built-in to mc:

 puts [mc "Directory contains %d files" $nfiles]

EKB I moved this example up to the top of the page and combined it with the intro text so it's easier to find.

AM Also very useful: the %1$s type format codes - with this you can interchange variables if needed.

  % mc "this is a %s test for %s" first anything
  this is a first test for anything
 
  % mc {this is a %2$s test for %1$s} first anything
  this is a anything test for first

Note the {} around the text to prevent the $ to be interpreted and looking for the variable $s.

RS 2007-01-08: Here's a simple self-contained example for testing:

 #!/usr/bin/env tclsh
 package require msgcat

 msgcat::mcset de yes Ja
 msgcat::mcset de no  Nein
 msgcat::mcset fr yes Oui
 msgcat::mcset fr no  Non

 proc localbool value {
    if {$value} {msgcat::mc yes} else {msgcat::mc no}
 }
 puts [localbool 0]/[localbool 1]
That's all. Save that to a file, and run it with different LANG settings:
 $ /Tcl/msgcat.tcl
 Nein/Ja
 $ LANG=fr /Tcl/msgcat.tcl
 Non/Oui
 $ LANG=en /Tcl/msgcat.tcl
 no/yes

HaO 2012-07-17: TIP 399 contains a patch to use msgcat in an environment which dynamically changes languages.

A file msgcat-1.5.0.tm is available in the linked feature request #3511941 . This file may be put to the tcl lib to be tested. In my experience, it is not sufficient, to have the file within the own project. It must be copied to the tcl installation beside the present file msgcat-1.4.4.tm.

• At this place, there were an alternate implementation and some use instructions. These are superseeded by the upper information.
• This feature is also included in the download files of #3544988 . There is also a tclapp tap-file available as download.

HaO 2012-07-17: I find it anoying and error-prone to repeate the locale for each mcset-command, even if it could already be known by the file name of the message catalog file.

As a consequence, one may try the extension of msgcat in the feature request #3544988 (patch, package and tclapp tap-file available in the download section) (updated 2012-07-25, namespace bug).

This extension basicly adds variants of the mcset and mcmset commands to use the locale given by the file name of the current sourced message cataloge file.

Example message file

Here is an example file contents with the file name de.msg:

mcflset File Datei
mcflset Exit Verlassen

The command name mcflset is an abreviation of "message catalogue with file locale set".

Set and get mc file locale

The mc file locale is set by the mcload command before a message file is sourced. The msgcat subcommand mcconfig is extended to get and set this locale:

% puts [mcconfig -mcfilelocale]
de
% mcconfig -mcfilelocale en
en

The new command mcflset is identical to:

mcset [mcconfig -mcfilelocale] <src> <translation>

Old and new syntax may be mixed, for example to set local variations (this is IMHO not recommended at all, better use two message files, but I didn't find a better example):

mcflset Hello "Hallo"
mcset de_CH Hello "Salü"

Setting mc file locale by command

The set-ability of the mc file locale is not important. It might be used, to set the default value for a bunch of values within program code (and not in an msg file).

mcconfig -mcfilelocale de
mcflset File Datei
mcflset Exit Verlassen

One must take care, that any mcload command may set it to another value. Specially package require commands may invoke mcload commands.

HaO 2012-07-17: Given the code with a localised error message:

if {[catch {open $File r} Err]} {
    puts stderr [mc "File error accessing '%s': %s" $File $Err]
}

and the German translation:

--de.msg--
msgcat::mcset de "File error accessing '%s': %s" "Zugriffsfehler Datei '%s': %s"
--eof--

I use tags instead of a default translation. The default (english) text is contained in the root translation:

--de.msg--
msgcat::mcset de errFile "Zugriffsfehler Datei '%s': %s"
--eof--
--ROOT.msg--
msgcat::mcset {} errFile "File error accessing '%s': %s"
--eof--
if {[catch {open $File r} Err]} {
    puts stderr [mc errFile $File $Err]
}

Why that ?

• If I change the default text, I do not have to change the translation keys
• It feels more systematic to me to separate text and code
• If a text is the same in english but different in german, I may not make any difference
• If I forget a translation, I get only a stupid tag. Nothing for lazy guys...

HaO 2012-07-24: To use a newer msgcat Version, it is to my experience not sufficient to have a new package in a custom auto_path. There is always the original found, I don't know why. A new package must be set to the default location.

Thus the new msgcat.tcl is renamed to msgcat-1.x.x.tm (1.x.x: version greater 1.4.5 which will be the version in tcl 8.5.12) and saved to:

• <tcl install folder>/lib/lib8/8.5

If the program is wrapped to an executable starkit (not .kit), one may save it to:

• <programname>.vfs/lib/lib8/8.5

If an application is wrapped using ActiveState TclApp, I did not found any way to wrap anything to the upper path. But I made a custom tap file containing a pckIndex.tcl and a msgcat.tcl and this worked (at least for a console application). The tap-file for msgcat-1.5.1 is here: msgcat-1.5.1.zip

Examples of using msgcat

• simple text editor
• HiLo-international
• multilingual menu
• Tk internationalization

See also

• msgcat magic
• msgcat and shortcut keys
• msgcat-Ready Script Utility
• msgcat-x
• ampersand magic
• locale
• localization
• message catalog
• Tk and msgcat