spirit-po | localization using GNU gettext po files , based on boost | Internationalization library

To begin, first obtain some .po files. PO files are created by translators, they contain a dictionary of translated strings. For examples from various GNU projects, see our test folder. Then, load the file and construct a spirit_po::catalog from it. The catalog object serves translation requests using the strings it loaded from the PO file. the translated form of "Hello world!" will be displayed. The result will be a const char * pointing to a string owned by the catalog. (Or, if the translation misses becaues this string wasn't in the catalog, it will simply return the english text "Hello world!", the same pointer it was passed in.). a string is translated, and also marked with a context string. Sometimes the same english phrase or sentence appears in your program in multiple places, but should be translated differently depending on context. The context string allows you to provide a hint to the translator and allows the program to disambiguate the two usages. (This particular example is unfortunately a poor one.). the catalog object will look up the C-format string in the catalog, and search for the plural form corresponding to number. This ensures that "shots" will be pluralized correctly no matter what language is used. (In many languages, there are more than two plural forms and language-specific logic is needed to determine the appropriate form to use based on the number. The translator provides this logic in the po-file header.) Then we use printf to substitute the numbers into the string. These examples are actually all rehash from gettext documentation -- the member functions gettext, pgettext, ngettext are all analogous to calls to the C library libintl. If you aren't already familiar with gettext, have a look at their documentation. Note: It is standard in gettext documentation examples to use functions like printf with translated strings, since it is a C library. However, if you are working in C++, you might be better off to use a type-safe alternative to printf. Otherwise, if the translator makes a mistake, or an adversary modifies the po files, you can get undefined behavior in your program with code like above. You might prefer to use something like tinyformat for instance.