This is gettext.info, produced by makeinfo version 4.0 from gettext.texi. INFO-DIR-SECTION GNU Gettext Utilities START-INFO-DIR-ENTRY * Gettext: (gettext). GNU gettext utilities. * gettextize: (gettext)gettextize Invocation. Prepare a package for gettext. * msgfmt: (gettext)msgfmt Invocation. Make MO files out of PO files. * msgmerge: (gettext)msgmerge Invocation. Update two PO files into one. * xgettext: (gettext)xgettext Invocation. Extract strings into a PO file. END-INFO-DIR-ENTRY This file provides documentation for GNU `gettext' utilities. It also serves as a reference for the free Translation Project. Copyright (C) 1995, 1996, 1997, 1998, 2001 Free Software Foundation, Inc. Permission is granted to make and distribute verbatim copies of this manual provided the copyright notice and this permission notice are preserved on all copies. Permission is granted to copy and distribute modified versions of this manual under the conditions for verbatim copying, provided that the entire resulting derived work is distributed under the terms of a permission notice identical to this one. Permission is granted to copy and distribute translations of this manual into another language, under the above conditions for modified versions, except that this permission notice may be stated in a translation approved by the Foundation.  File: gettext.info, Node: gettext, Next: Comparison, Prev: catgets, Up: Programmers About `gettext' =============== The definition of the `gettext' interface comes from a Uniforum proposal and it is followed by at least one major Unix vendor (Sun) in its last developments. It is not specified in any official standard, though. The main points about this solution is that it does not follow the method of normal file handling (open-use-close) and that it does not burden the programmer so many task, especially the unique key handling. Of course here is also a unique key needed, but this key is the message itself (how long or short it is). See *Note Comparison:: for a more detailed comparison of the two methods. The following section contains a rather detailed description of the interface. We make it that detailed because this is the interface we chose for the GNU `gettext' Library. Programmers interested in using this library will be interested in this description. * Menu: * Interface to gettext:: The interface * Ambiguities:: Solving ambiguities * Locating Catalogs:: Locating message catalog files * Charset conversion:: How to request conversion to Unicode * Plural forms:: Additional functions for handling plurals * GUI program problems:: Another technique for solving ambiguities * Optimized gettext:: Optimization of the *gettext functions  File: gettext.info, Node: Interface to gettext, Next: Ambiguities, Prev: gettext, Up: gettext The Interface ------------- The minimal functionality an interface must have is a) to select a domain the strings are coming from (a single domain for all programs is not reasonable because its construction and maintenance is difficult, perhaps impossible) and b) to access a string in a selected domain. This is principally the description of the `gettext' interface. It has a global domain which unqualified usages reference. Of course this domain is selectable by the user. char *textdomain (const char *domain_name); This provides the possibility to change or query the current status of the current global domain of the `LC_MESSAGE' category. The argument is a null-terminated string, whose characters must be legal in the use in filenames. If the DOMAIN_NAME argument is `NULL', the function return the current value. If no value has been set before, the name of the default domain is returned: _messages_. Please note that although the return value of `textdomain' is of type `char *' no changing is allowed. It is also important to know that no checks of the availability are made. If the name is not available you will see this by the fact that no translations are provided. To use a domain set by `textdomain' the function char *gettext (const char *msgid); is to be used. This is the simplest reasonable form one can imagine. The translation of the string MSGID is returned if it is available in the current domain. If not available the argument itself is returned. If the argument is `NULL' the result is undefined. One things which should come into mind is that no explicit dependency to the used domain is given. The current value of the domain for the `LC_MESSAGES' locale is used. If this changes between two executions of the same `gettext' call in the program, both calls reference a different message catalog. For the easiest case, which is normally used in internationalized packages, once at the beginning of execution a call to `textdomain' is issued, setting the domain to a unique name, normally the package name. In the following code all strings which have to be translated are filtered through the gettext function. That's all, the package speaks your language.  File: gettext.info, Node: Ambiguities, Next: Locating Catalogs, Prev: Interface to gettext, Up: gettext Solving Ambiguities ------------------- While this single name domain works well for most applications there might be the need to get translations from more than one domain. Of course one could switch between different domains with calls to `textdomain', but this is really not convenient nor is it fast. A possible situation could be one case subject to discussion during this writing: all error messages of functions in the set of common used functions should go into a separate domain `error'. By this mean we would only need to translate them once. Another case are messages from a library, as these _have_ to be independent of the current domain set by the application. For this reasons there are two more functions to retrieve strings: char *dgettext (const char *domain_name, const char *msgid); char *dcgettext (const char *domain_name, const char *msgid, int category); Both take an additional argument at the first place, which corresponds to the argument of `textdomain'. The third argument of `dcgettext' allows to use another locale but `LC_MESSAGES'. But I really don't know where this can be useful. If the DOMAIN_NAME is `NULL' or CATEGORY has an value beside the known ones, the result is undefined. It should also be noted that this function is not part of the second known implementation of this function family, the one found in Solaris. A second ambiguity can arise by the fact, that perhaps more than one domain has the same name. This can be solved by specifying where the needed message catalog files can be found. char *bindtextdomain (const char *domain_name, const char *dir_name); Calling this function binds the given domain to a file in the specified directory (how this file is determined follows below). Especially a file in the systems default place is not favored against the specified file anymore (as it would be by solely using `textdomain'). A `NULL' pointer for the DIR_NAME parameter returns the binding associated with DOMAIN_NAME. If DOMAIN_NAME itself is `NULL' nothing happens and a `NULL' pointer is returned. Here again as for all the other functions is true that none of the return value must be changed! It is important to remember that relative path names for the DIR_NAME parameter can be trouble. Since the path is always computed relative to the current directory different results will be achieved when the program executes a `chdir' command. Relative paths should always be avoided to avoid dependencies and unreliabilities.  File: gettext.info, Node: Locating Catalogs, Next: Charset conversion, Prev: Ambiguities, Up: gettext Locating Message Catalog Files ------------------------------ Because many different languages for many different packages have to be stored we need some way to add these information to file message catalog files. The way usually used in Unix environments is have this encoding in the file name. This is also done here. The directory name given in `bindtextdomain's second argument (or the default directory), followed by the value and name of the locale and the domain name are concatenated: DIR_NAME/LOCALE/LC_CATEGORY/DOMAIN_NAME.mo The default value for DIR_NAME is system specific. For the GNU library, and for packages adhering to its conventions, it's: /usr/local/share/locale LOCALE is the value of the locale whose name is this `LC_CATEGORY'. For `gettext' and `dgettext' this `LC_CATEGORY' is always `LC_MESSAGES'.(1) The value of the locale is determined through `setlocale (LC_CATEGORY, NULL)'. (2) `dcgettext' specifies the locale category by the third argument. ---------- Footnotes ---------- (1) Some system, eg Ultrix, don't have `LC_MESSAGES'. Here we use a more or less arbitrary value for it, namely 1729, the smallest positive integer which can be represented in two different ways as the sum of two cubes. (2) When the system does not support `setlocale' its behavior in setting the locale values is simulated by looking at the environment variables.  File: gettext.info, Node: Charset conversion, Next: Plural forms, Prev: Locating Catalogs, Up: gettext How to specify the output character set `gettext' uses ------------------------------------------------------ `gettext' not only looks up a translation in a message catalog. It also converts the translation on the fly to the desired output character set. This is useful if the user is working in a different character set than the translator who created the message catalog, because it avoids distributing variants of message catalogs which differ only in the character set. The output character set is, by default, the value of `nl_langinfo (CODESET)', which depends on the `LC_CTYPE' part of the current locale. But programs which store strings in a locale independent way (e.g. UTF-8) can request that `gettext' and related functions return the translations in that encoding, by use of the `bind_textdomain_codeset' function. Note that the MSGID argument to `gettext' is not subject to character set conversion. Also, when `gettext' does not find a translation for MSGID, it returns MSGID unchanged - independently of the current output character set. It is therefore recommended that all MSGIDs be US-ASCII strings. - Function: char * bind_textdomain_codeset (const char *DOMAINNAME, const char *CODESET) The `bind_textdomain_codeset' function can be used to specify the output character set for message catalogs for domain DOMAINNAME. The CODESET argument must be a valid codeset name which can be used for the `iconv_open' function, or a null pointer. If the CODESET parameter is the null pointer, `bind_textdomain_codeset' returns the currently selected codeset for the domain with the name DOMAINNAME. It returns `NULL' if no codeset has yet been selected. The `bind_textdomain_codeset' function can be used several times. If used multiple times with the same DOMAINNAME argument, the later call overrides the settings made by the earlier one. The `bind_textdomain_codeset' function returns a pointer to a string containing the name of the selected codeset. The string is allocated internally in the function and must not be changed by the user. If the system went out of core during the execution of `bind_textdomain_codeset', the return value is `NULL' and the global variable ERRNO is set accordingly.  File: gettext.info, Node: Plural forms, Next: GUI program problems, Prev: Charset conversion, Up: gettext Additional functions for plural forms ------------------------------------- The functions of the `gettext' family described so far (and all the `catgets' functions as well) have one problem in the real world which have been neglected completely in all existing approaches. What is meant here is the handling of plural forms. Looking through Unix source code before the time anybody thought about internationalization (and, sadly, even afterwards) one can often find code similar to the following: printf ("%d file%s deleted", n, n == 1 ? "" : "s"); After the first complaints from people internationalizing the code people either completely avoided formulations like this or used strings like `"file(s)"'. Both look unnatural and should be avoided. First tries to solve the problem correctly looked like this: if (n == 1) printf ("%d file deleted", n); else printf ("%d files deleted", n); But this does not solve the problem. It helps languages where the plural form of a noun is not simply constructed by adding an `s' but that is all. Once again people fell into the trap of believing the rules their language is using are universal. But the handling of plural forms differs widely between the language families. For example, Rafal Maszkowski `' reports: In Polish we use e.g. plik (file) this way: 1 plik 2,3,4 pliki 5-21 pliko'w 22-24 pliki 25-31 pliko'w and so on (o' means 8859-2 oacute which should be rather okreska, similar to aogonek). There are two things which can differ between languages (and even inside language families); * The form how plural forms are build differs. This is a problem with languages which have many irregularities. German, for instance, is a drastic case. Though English and German are part of the same language family (Germanic), the almost regular forming of plural noun forms (appending an `s') is hardly found in German. * The number of plural forms differ. This is somewhat surprising for those who only have experiences with Romanic and Germanic languages since here the number is the same (there are two). But other language families have only one form or many forms. More information on this in an extra section. The consequence of this is that application writers should not try to solve the problem in their code. This would be localization since it is only usable for certain, hardcoded language environments. Instead the extended `gettext' interface should be used. These extra functions are taking instead of the one key string two strings and a numerical argument. The idea behind this is that using the numerical argument and the first string as a key, the implementation can select using rules specified by the translator the right plural form. The two string arguments then will be used to provide a return value in case no message catalog is found (similar to the normal `gettext' behavior). In this case the rules for Germanic language is used and it is assumed that the first string argument is the singular form, the second the plural form. This has the consequence that programs without language catalogs can display the correct strings only if the program itself is written using a Germanic language. This is a limitation but since the GNU C library (as well as the GNU `gettext' package) are written as part of the GNU package and the coding standards for the GNU project require program being written in English, this solution nevertheless fulfills its purpose. - Function: char * ngettext (const char *MSGID1, const char *MSGID2, unsigned long int N) The `ngettext' function is similar to the `gettext' function as it finds the message catalogs in the same way. But it takes two extra arguments. The MSGID1 parameter must contain the singular form of the string to be converted. It is also used as the key for the search in the catalog. The MSGID2 parameter is the plural form. The parameter N is used to determine the plural form. If no message catalog is found MSGID1 is returned if `n == 1', otherwise `msgid2'. An example for the use of this function is: printf (ngettext ("%d file removed", "%d files removed", n), n); Please note that the numeric value N has to be passed to the `printf' function as well. It is not sufficient to pass it only to `ngettext'. - Function: char * dngettext (const char *DOMAIN, const char *MSGID1, const char *MSGID2, unsigned long int N) The `dngettext' is similar to the `dgettext' function in the way the message catalog is selected. The difference is that it takes two extra parameter to provide the correct plural form. These two parameters are handled in the same way `ngettext' handles them. - Function: char * dcngettext (const char *DOMAIN, const char *MSGID1, const char *MSGID2, unsigned long int N, int CATEGORY) The `dcngettext' is similar to the `dcgettext' function in the way the message catalog is selected. The difference is that it takes two extra parameter to provide the correct plural form. These two parameters are handled in the same way `ngettext' handles them. Now, how do these functions solve the problem of the plural forms? Without the input of linguists (which was not available) it was not possible to determine whether there are only a few different forms in which plural forms are formed or whether the number can increase with every new supported language. Therefore the solution implemented is to allow the translator to specify the rules of how to select the plural form. Since the formula varies with every language this is the only viable solution except for hardcoding the information in the code (which still would require the possibility of extensions to not prevent the use of new languages). The information about the plural form selection has to be stored in the header entry of the PO file (the one with the empty `msgid' string). The plural form information looks like this: Plural-Forms: nplurals=2; plural=n == 1 ? 0 : 1; The `nplurals' value must be a decimal number which specifies how many different plural forms exist for this language. The string following `plural' is an expression which is using the C language syntax. Exceptions are that no negative numbers are allowed, numbers must be decimal, and the only variable allowed is `n'. This expression will be evaluated whenever one of the functions `ngettext', `dngettext', or `dcngettext' is called. The numeric value passed to these functions is then substituted for all uses of the variable `n' in the expression. The resulting value then must be greater or equal to zero and smaller than the value given as the value of `nplurals'. The following rules are known at this point. The language with families are listed. But this does not necessarily mean the information can be generalized for the whole family (as can be easily seen in the table below).(1) Only one form: Some languages only require one single form. There is no distinction between the singular and plural form. An appropriate header entry would look like this: Plural-Forms: nplurals=1; plural=0; Languages with this property include: Finno-Ugric family Hungarian Asian family Japanese Turkic/Altaic family Turkish Two forms, singular used for one only This is the form used in most existing programs since it is what English is using. A header entry would look like this: Plural-Forms: nplurals=2; plural=n != 1; (Note: this uses the feature of C expressions that boolean expressions have to value zero or one.) Languages with this property include: Germanic family Danish, Dutch, English, German, Norwegian, Swedish Finno-Ugric family Estonian, Finnish Latin/Greek family Greek Semitic family Hebrew Romanic family Italian, Spanish Artificial Esperanto Two forms, singular used for zero and one Exceptional case in the language family. The header entry would be: Plural-Forms: nplurals=2; plural=n>1; Languages with this property include: Romanic family French Three forms, special cases for one and two The header entry would be: Plural-Forms: nplurals=3; plural=n==1 ? 0 : n==2 ? 1 : 2; Languages with this property include: Celtic Gaeilge Three forms, special case for numbers ending in 1[2-9] The header entry would look like this: Plural-Forms: nplurals=3; \ plural=n%10==1 && n%100!=11 ? 0 : \ n%10>=2 && (n%100<10 || n%100>=20) ? 1 : 2; Languages with this property include: Baltic family Lithuanian Three forms, special cases for numbers ending in 1 and 2, 3, 4, except those ending in 1[1-4] The header entry would look like this: Plural-Forms: nplurals=3; \ plural=n%10==1 && n%100!=11 ? 0 : \ n%10>=2 && n%10<=4 && (n%100<10 || n%100>=20) ? 1 : 2; Languages with this property include: Slavic family Czech, Russian, Slovak, Ukrainian Three forms, special case for one and some numbers ending in 2, 3, or 4 The header entry would look like this: Plural-Forms: nplurals=3; \ plural=n==1 ? 0 : \ n%10>=2 && n%10<=4 && (n%100<10 || n%100>=20) ? 1 : 2; (Continuation in the next line is possible.) Languages with this property include: Slavic family Polish Four forms, special case for one and all numbers ending in 02, 03, or 04 The header entry would look like this: Plural-Forms: nplurals=4; \ plural=n%100==1 ? 0 : n%100==2 ? 1 : n%100==3 || n%100==4 ? 2 : 3; Languages with this property include: Slavic family Slovenian ---------- Footnotes ---------- (1) Additions are welcome. Send appropriate information to .  File: gettext.info, Node: GUI program problems, Next: Optimized gettext, Prev: Plural forms, Up: gettext How to use `gettext' in GUI programs ------------------------------------ One place where the `gettext' functions, if used normally, have big problems is within programs with graphical user interfaces (GUIs). The problem is that many of the strings which have to be translated are very short. They have to appear in pull-down menus which restricts the length. But strings which are not containing entire sentences or at least large fragments of a sentence may appear in more than one situation in the program but might have different translations. This is especially true for the one-word strings which are frequently used in GUI programs. As a consequence many people say that the `gettext' approach is wrong and instead `catgets' should be used which indeed does not have this problem. But there is a very simple and powerful method to handle these kind of problems with the `gettext' functions. As as example consider the following fictional situation. A GUI program has a menu bar with the following entries: +------------+------------+--------------------------------------+ | File | Printer | | +------------+------------+--------------------------------------+ | Open | | Select | | New | | Open | +----------+ | Connect | +----------+ To have the strings `File', `Printer', `Open', `New', `Select', and `Connect' translated there has to be at some point in the code a call to a function of the `gettext' family. But in two places the string passed into the function would be `Open'. The translations might not be the same and therefore we are in the dilemma described above. One solution to this problem is to artificially enlengthen the strings to make them unambiguous. But what would the program do if no translation is available? The enlengthened string is not what should be printed. So we should use a little bit modified version of the functions. To enlengthen the strings a uniform method should be used. E.g., in the example above the strings could be chosen as Menu|File Menu|Printer Menu|File|Open Menu|File|New Menu|Printer|Select Menu|Printer|Open Menu|Printer|Connect Now all the strings are different and if now instead of `gettext' the following little wrapper function is used, everything works just fine: char * sgettext (const char *msgid) { char *msgval = gettext (msgid); if (msgval == msgid) msgval = strrchr (msgid, '|') + 1; return msgval; } What this little function does is to recognize the case when no translation is available. This can be done very efficiently by a pointer comparison since the return value is the input value. If there is no translation we know that the input string is in the format we used for the Menu entries and therefore contains a `|' character. We simply search for the last occurrence of this character and return a pointer to the character following it. That's it! If one now consistently uses the enlengthened string form and replaces the `gettext' calls with calls to `sgettext' (this is normally limited to very few places in the GUI implementation) then it is possible to produce a program which can be internationalized. The other `gettext' functions (`dgettext', `dcgettext' and the `ngettext' equivalents) can and should have corresponding functions as well which look almost identical, except for the parameters and the call to the underlying function. Now there is of course the question why such functions do not exist in the GNU gettext package? There are two parts of the answer to this question. * They are easy to write and therefore can be provided by the project they are used in. This is not an answer by itself and must be seen together with the second part which is: * There is no way the gettext package can contain a version which can work everywhere. The problem is the selection of the character to separate the prefix from the actual string in the enlenghtened string. The examples above used `|' which is a quite good choice because it resembles a notation frequently used in this context and it also is a character not often used in message strings. But what if the character is used in message strings? Or if the chose character is not available in the character set on the machine one compiles (e.g., `|' is not required to exist for ISO C; this is why the `iso646.h' file exists in ISO C programming environments). There is only one more comment to be said. The wrapper function above requires that the translations strings are not enlengthened themselves. This is only logical. There is no need to disambiguate the strings (since they are never used as keys for a search) and one also saves quite some memory and disk space by doing this.  File: gettext.info, Node: Optimized gettext, Prev: GUI program problems, Up: gettext Optimization of the *gettext functions -------------------------------------- At this point of the discussion we should talk about an advantage of the GNU `gettext' implementation. Some readers might have pointed out that an internationalized program might have a poor performance if some string has to be translated in an inner loop. While this is unavoidable when the string varies from one run of the loop to the other it is simply a waste of time when the string is always the same. Take the following example: { while (...) { puts (gettext ("Hello world")); } } When the locale selection does not change between two runs the resulting string is always the same. One way to use this is: { str = gettext ("Hello world"); while (...) { puts (str); } } But this solution is not usable in all situation (e.g. when the locale selection changes) nor does it lead to legible code. For this reason, GNU `gettext' caches previous translation results. When the same translation is requested twice, with no new message catalogs being loaded in between, `gettext' will, the second time, find the result through a single cache lookup.  File: gettext.info, Node: Comparison, Next: Using libintl.a, Prev: gettext, Up: Programmers Comparing the Two Interfaces ============================ The following discussion is perhaps a little bit colored. As said above we implemented GNU `gettext' following the Uniforum proposal and this surely has its reasons. But it should show how we came to this decision. First we take a look at the developing process. When we write an application using NLS provided by `gettext' we proceed as always. Only when we come to a string which might be seen by the users and thus has to be translated we use `gettext("...")' instead of `"..."'. At the beginning of each source file (or in a central header file) we define #define gettext(String) (String) Even this definition can be avoided when the system supports the `gettext' function in its C library. When we compile this code the result is the same as if no NLS code is used. When you take a look at the GNU `gettext' code you will see that we use `_("...")' instead of `gettext("...")'. This reduces the number of additional characters per translatable string to _3_ (in words: three). When now a production version of the program is needed we simply replace the definition #define _(String) (String) by #include #define _(String) gettext (String) Additionally we run the program `xgettext' on all source code file which contain translatable strings and that's it: we have a running program which does not depend on translations to be available, but which can use any that becomes available. The same procedure can be done for the `gettext_noop' invocations (*note Special cases::). One usually defines `gettext_noop' as a no-op macro. So you should consider the following code for your project: #define gettext_noop(String) (String) #define N_(String) gettext_noop (String) `N_' is a short form similar to `_'. The `Makefile' in the `po/' directory of GNU `gettext' knows by default both of the mentioned short forms so you are invited to follow this proposal for your own ease. Now to `catgets'. The main problem is the work for the programmer. Every time he comes to a translatable string he has to define a number (or a symbolic constant) which has also be defined in the message catalog file. He also has to take care for duplicate entries, duplicate message IDs etc. If he wants to have the same quality in the message catalog as the GNU `gettext' program provides he also has to put the descriptive comments for the strings and the location in all source code files in the message catalog. This is nearly a Mission: Impossible. But there are also some points people might call advantages speaking for `catgets'. If you have a single word in a string and this string is used in different contexts it is likely that in one or the other language the word has different translations. Example: printf ("%s: %d", gettext ("number"), number_of_errors) printf ("you should see %d %s", number_count, number_count == 1 ? gettext ("number") : gettext ("numbers")) Here we have to translate two times the string `"number"'. Even if you do not speak a language beside English it might be possible to recognize that the two words have a different meaning. In German the first appearance has to be translated to `"Anzahl"' and the second to `"Zahl"'. Now you can say that this example is really esoteric. And you are right! This is exactly how we felt about this problem and decide that it does not weight that much. The solution for the above problem could be very easy: printf ("%s %d", gettext ("number:"), number_of_errors) printf (number_count == 1 ? gettext ("you should see %d number") : gettext ("you should see %d numbers"), number_count) We believe that we can solve all conflicts with this method. If it is difficult one can also consider changing one of the conflicting string a little bit. But it is not impossible to overcome. `catgets' allows same original entry to have different translations, but `gettext' has another, scalable approach for solving ambiguities of this kind: *Note Ambiguities::.  File: gettext.info, Node: Using libintl.a, Next: gettext grok, Prev: Comparison, Up: Programmers Using libintl.a in own programs =============================== Starting with version 0.9.4 the library `libintl.h' should be self-contained. I.e., you can use it in your own programs without providing additional functions. The `Makefile' will put the header and the library in directories selected using the `$(prefix)'. One exception of the above is found on HP-UX 10.01 systems. Here the C library does not contain the `alloca' function (and the HP compiler does not generate it inlined). But it is not intended to rewrite the whole library just because of this dumb system. Instead include the `alloca' function in all package you use the `libintl.a' in.  File: gettext.info, Node: gettext grok, Next: Temp Programmers, Prev: Using libintl.a, Up: Programmers Being a `gettext' grok ====================== To fully exploit the functionality of the GNU `gettext' library it is surely helpful to read the source code. But for those who don't want to spend that much time in reading the (sometimes complicated) code here is a list comments: * Changing the language at runtime For interactive programs it might be useful to offer a selection of the used language at runtime. To understand how to do this one need to know how the used language is determined while executing the `gettext' function. The method which is presented here only works correctly with the GNU implementation of the `gettext' functions. In the function `dcgettext' at every call the current setting of the highest priority environment variable is determined and used. Highest priority means here the following list with decreasing priority: 1. `LANGUAGE' 2. `LC_ALL' 3. `LC_xxx', according to selected locale 4. `LANG' Afterwards the path is constructed using the found value and the translation file is loaded if available. What is now when the value for, say, `LANGUAGE' changes. According to the process explained above the new value of this variable is found as soon as the `dcgettext' function is called. But this also means the (perhaps) different message catalog file is loaded. In other words: the used language is changed. But there is one little hook. The code for gcc-2.7.0 and up provides some optimization. This optimization normally prevents the calling of the `dcgettext' function as long as no new catalog is loaded. But if `dcgettext' is not called the program also cannot find the `LANGUAGE' variable be changed (*note Optimized gettext::). A solution for this is very easy. Include the following code in the language switching function. /* Change language. */ setenv ("LANGUAGE", "fr", 1); /* Make change known. */ { extern int _nl_msg_cat_cntr; ++_nl_msg_cat_cntr; } The variable `_nl_msg_cat_cntr' is defined in `loadmsgcat.c'. The programmer will find himself in need for a construct like this only when developing programs which do run longer and provide the user to select the language at runtime. Non-interactive programs (like all these little Unix tools) should never need this.  File: gettext.info, Node: Temp Programmers, Prev: gettext grok, Up: Programmers Temporary Notes for the Programmers Chapter =========================================== * Menu: * Temp Implementations:: Temporary - Two Possible Implementations * Temp catgets:: Temporary - About `catgets' * Temp WSI:: Temporary - Why a single implementation * Temp Notes:: Temporary - Notes  File: gettext.info, Node: Temp Implementations, Next: Temp catgets, Prev: Temp Programmers, Up: Temp Programmers Temporary - Two Possible Implementations ---------------------------------------- There are two competing methods for language independent messages: the X/Open `catgets' method, and the Uniforum `gettext' method. The `catgets' method indexes messages by integers; the `gettext' method indexes them by their English translations. The `catgets' method has been around longer and is supported by more vendors. The `gettext' method is supported by Sun, and it has been heard that the COSE multi-vendor initiative is supporting it. Neither method is a POSIX standard; the POSIX.1 committee had a lot of disagreement in this area. Neither one is in the POSIX standard. There was much disagreement in the POSIX.1 committee about using the `gettext' routines vs. `catgets' (XPG). In the end the committee couldn't agree on anything, so no messaging system was included as part of the standard. I believe the informative annex of the standard includes the XPG3 messaging interfaces, "...as an example of a messaging system that has been implemented..." They were very careful not to say anywhere that you should use one set of interfaces over the other. For more on this topic please see the Programming for Internationalization FAQ.  File: gettext.info, Node: Temp catgets, Next: Temp WSI, Prev: Temp Implementations, Up: Temp Programmers Temporary - About `catgets' --------------------------- There have been a few discussions of late on the use of `catgets' as a base. I think it important to present both sides of the argument and hence am opting to play devil's advocate for a little bit. I'll not deny the fact that `catgets' could have been designed a lot better. It currently has quite a number of limitations and these have already been pointed out. However there is a great deal to be said for consistency and standardization. A common recurring problem when writing Unix software is the myriad portability problems across Unix platforms. It seems as if every Unix vendor had a look at the operating system and found parts they could improve upon. Undoubtedly, these modifications are probably innovative and solve real problems. However, software developers have a hard time keeping up with all these changes across so many platforms. And this has prompted the Unix vendors to begin to standardize their systems. Hence the impetus for Spec1170. Every major Unix vendor has committed to supporting this standard and every Unix software developer waits with glee the day they can write software to this standard and simply recompile (without having to use autoconf) across different platforms. As I understand it, Spec1170 is roughly based upon version 4 of the X/Open Portability Guidelines (XPG4). Because `catgets' and friends are defined in XPG4, I'm led to believe that `catgets' is a part of Spec1170 and hence will become a standardized component of all Unix systems.  File: gettext.info, Node: Temp WSI, Next: Temp Notes, Prev: Temp catgets, Up: Temp Programmers Temporary - Why a single implementation --------------------------------------- Now it seems kind of wasteful to me to have two different systems installed for accessing message catalogs. If we do want to remedy `catgets' deficiencies why don't we try to expand `catgets' (in a compatible manner) rather than implement an entirely new system. Otherwise, we'll end up with two message catalog access systems installed with an operating system - one set of routines for packages using GNU `gettext' for their internationalization, and another set of routines (catgets) for all other software. Bloated? Supposing another catalog access system is implemented. Which do we recommend? At least for Linux, we need to attract as many software developers as possible. Hence we need to make it as easy for them to port their software as possible. Which means supporting `catgets'. We will be implementing the `libintl' code within our `libc', but does this mean we also have to incorporate another message catalog access scheme within our `libc' as well? And what about people who are going to be using the `libintl' + non-`catgets' routines. When they port their software to other platforms, they're now going to have to include the front-end (`libintl') code plus the back-end code (the non-`catgets' access routines) with their software instead of just including the `libintl' code with their software. Message catalog support is however only the tip of the iceberg. What about the data for the other locale categories. They also have a number of deficiencies. Are we going to abandon them as well and develop another duplicate set of routines (should `libintl' expand beyond message catalog support)? Like many parts of Unix that can be improved upon, we're stuck with balancing compatibility with the past with useful improvements and innovations for the future.  File: gettext.info, Node: Temp Notes, Prev: Temp WSI, Up: Temp Programmers Temporary - Notes ----------------- X/Open agreed very late on the standard form so that many implementations differ from the final form. Both of my system (old Linux catgets and Ultrix-4) have a strange variation. OK. After incorporating the last changes I have to spend some time on making the GNU/Linux `libc' `gettext' functions. So in future Solaris is not the only system having `gettext'.  File: gettext.info, Node: Translators, Next: Maintainers, Prev: Programmers, Up: Top The Translator's View ********************* * Menu: * Trans Intro 0:: Introduction 0 * Trans Intro 1:: Introduction 1 * Discussions:: Discussions * Organization:: Organization * Information Flow:: Information Flow  File: gettext.info, Node: Trans Intro 0, Next: Trans Intro 1, Prev: Translators, Up: Translators Introduction 0 ============== Free software is going international! The Translation Project is a way to get maintainers, translators and users all together, so free software will gradually become able to speak many native languages. The GNU `gettext' tool set contains _everything_ maintainers need for internationalizing their packages for messages. It also contains quite useful tools for helping translators at localizing messages to their native language, once a package has already been internationalized. To achieve the Translation Project, we need many interested people who like their own language and write it well, and who are also able to synergize with other translators speaking the same language. If you'd like to volunteer to _work_ at translating messages, please send mail to your translating team. Each team has its own mailing list, courtesy of Linux International. You may reach your translating team at the address `LL@li.org', replacing LL by the two-letter ISO 639 code for your language. Language codes are _not_ the same as country codes given in ISO 3166. The following translating teams exist: Chinese `zh', Czech `cs', Danish `da', Dutch `nl', Esperanto `eo', Finnish `fi', French `fr', Irish `ga', German `de', Greek `el', Italian `it', Japanese `ja', Indonesian `in', Norwegian `no', Polish `pl', Portuguese `pt', Russian `ru', Spanish `es', Swedish `sv' and Turkish `tr'. For example, you may reach the Chinese translating team by writing to `zh@li.org'. When you become a member of the translating team for your own language, you may subscribe to its list. For example, Swedish people can send a message to `sv-request@li.org', having this message body: subscribe Keep in mind that team members should be interested in _working_ at translations, or at solving translational difficulties, rather than merely lurking around. If your team does not exist yet and you want to start one, please write to `translation@iro.umontreal.ca'; you will then reach the coordinator for all translator teams. A handful of GNU packages have already been adapted and provided with message translations for several languages. Translation teams have begun to organize, using these packages as a starting point. But there are many more packages and many languages for which we have no volunteer translators. If you would like to volunteer to work at translating messages, please send mail to `translation@iro.umontreal.ca' indicating what language(s) you can work on.  File: gettext.info, Node: Trans Intro 1, Next: Discussions, Prev: Trans Intro 0, Up: Translators Introduction 1 ============== This is now official, GNU is going international! Here is the announcement submitted for the January 1995 GNU Bulletin: A handful of GNU packages have already been adapted and provided with message translations for several languages. Translation teams have begun to organize, using these packages as a starting point. But there are many more packages and many languages for which we have no volunteer translators. If you'd like to volunteer to work at translating messages, please send mail to `translation@iro.umontreal.ca' indicating what language(s) you can work on. This document should answer many questions for those who are curious about the process or would like to contribute. Please at least skim over it, hoping to cut down a little of the high volume of e-mail generated by this collective effort towards internationalization of free software. Most free programming which is widely shared is done in English, and currently, English is used as the main communicating language between national communities collaborating to free software. This very document is written in English. This will not change in the foreseeable future. However, there is a strong appetite from national communities for having more software able to write using national language and habits, and there is an on-going effort to modify free software in such a way that it becomes able to do so. The experiments driven so far raised an enthusiastic response from pretesters, so we believe that internationalization of free software is dedicated to succeed. For suggestion clarifications, additions or corrections to this document, please e-mail to `translation@iro.umontreal.ca'.  File: gettext.info, Node: Discussions, Next: Organization, Prev: Trans Intro 1, Up: Translators Discussions =========== Facing this internationalization effort, a few users expressed their concerns. Some of these doubts are presented and discussed, here. * Smaller groups Some languages are not spoken by a very large number of people, so people speaking them sometimes consider that there may not be all that much demand such versions of free software packages. Moreover, many people being _into computers_, in some countries, generally seem to prefer English versions of their software. On the other end, people might enjoy their own language a lot, and be very motivated at providing to themselves the pleasure of having their beloved free software speaking their mother tongue. They do themselves a personal favor, and do not pay that much attention to the number of people beneficiating of their work. * Misinterpretation Other users are shy to push forward their own language, seeing in this some kind of misplaced propaganda. Someone thought there must be some users of the language over the networks pestering other people with it. But any spoken language is worth localization, because there are people behind the language for whom the language is important and dear to their hearts. * Odd translations The biggest problem is to find the right translations so that everybody can understand the messages. Translations are usually a little odd. Some people get used to English, to the extent they may find translations into their own language "rather pushy, obnoxious and sometimes even hilarious." As a French speaking man, I have the experience of those instruction manuals for goods, so poorly translated in French in Korea or Taiwan... The fact is that we sometimes have to create a kind of national computer culture, and this is not easy without the collaboration of many people liking their mother tongue. This is why translations are better achieved by people knowing and loving their own language, and ready to work together at improving the results they obtain. * Dependencies over the GPL Some people wonder if using GNU `gettext' necessarily brings their package under the protective wing of the GNU General Public License, when they do not want to make their program free, or want other kinds of freedom. The simplest answer is yes. The mere marking of localizable strings in a package, or conditional inclusion of a few lines for initialization, is not really including GPL'ed code. However, the localization routines themselves are under the GPL and would bring the remainder of the package under the GPL if they were distributed with it. So, I presume that, for those for which this is a problem, it could be circumvented by letting to the end installers the burden of assembling a package prepared for localization, but not providing the localization routines themselves.