gawk: Programmer i18n

 
 13.3 Internationalizing 'awk' Programs
 ======================================
 
 'gawk' provides the following variables for internationalization:
 
 'TEXTDOMAIN'
      This variable indicates the application's text domain.  For
      compatibility with GNU 'gettext', the default value is
      '"messages"'.
 
 '_"your message here"'
      String constants marked with a leading underscore are candidates
      for translation at runtime.  String constants without a leading
      underscore are not translated.
 
    'gawk' provides the following functions for internationalization:
 
 'dcgettext(STRING [, DOMAIN [, CATEGORY]])'
      Return the translation of STRING in text domain DOMAIN for locale
      category CATEGORY.  The default value for DOMAIN is the current
      value of 'TEXTDOMAIN'.  The default value for CATEGORY is
      '"LC_MESSAGES"'.
 
      If you supply a value for CATEGORY, it must be a string equal to
      one of the known locale categories described in SeeExplaining
      gettext.  You must also supply a text domain.  Use 'TEXTDOMAIN'
      if you want to use the current domain.
 
           CAUTION: The order of arguments to the 'awk' version of the
           'dcgettext()' function is purposely different from the order
           for the C version.  The 'awk' version's order was chosen to be
           simple and to allow for reasonable 'awk'-style default
           arguments.
 
 'dcngettext(STRING1, STRING2, NUMBER [, DOMAIN [, CATEGORY]])'
      Return the plural form used for NUMBER of the translation of
      STRING1 and STRING2 in text domain DOMAIN for locale category
      CATEGORY.  STRING1 is the English singular variant of a message,
      and STRING2 is the English plural variant of the same message.  The
      default value for DOMAIN is the current value of 'TEXTDOMAIN'.  The
      default value for CATEGORY is '"LC_MESSAGES"'.
 
      The same remarks about argument order as for the 'dcgettext()'
      function apply.
 
 'bindtextdomain(DIRECTORY [, DOMAIN ])'
      Change the directory in which 'gettext' looks for '.gmo' files, in
      case they will not or cannot be placed in the standard locations
      (e.g., during testing).  Return the directory in which DOMAIN is
      "bound."
 
      The default DOMAIN is the value of 'TEXTDOMAIN'.  If DIRECTORY is
      the null string ('""'), then 'bindtextdomain()' returns the current
      binding for the given DOMAIN.
 
    To use these facilities in your 'awk' program, follow these steps:
 
   1. Set the variable 'TEXTDOMAIN' to the text domain of your program.
      This is best done in a 'BEGIN' rule (SeeBEGIN/END), or it can
      also be done via the '-v' command-line option (SeeOptions):
 
           BEGIN {
               TEXTDOMAIN = "guide"
               ...
           }
 
   2. Mark all translatable strings with a leading underscore ('_')
      character.  It _must_ be adjacent to the opening quote of the
      string.  For example:
 
           print _"hello, world"
           x = _"you goofed"
           printf(_"Number of users is %d\n", nusers)
 
   3. If you are creating strings dynamically, you can still translate
      them, using the 'dcgettext()' built-in function:(1)
 
           if (groggy)
               message = dcgettext("%d customers disturbing me\n", "adminprog")
           else
               message = dcgettext("enjoying %d customers\n", "adminprog")
           printf(message, ncustomers)
 
      Here, the call to 'dcgettext()' supplies a different text domain
      ('"adminprog"') in which to find the message, but it uses the
      default '"LC_MESSAGES"' category.
 
      The previous example only works if 'ncustomers' is greater than
      one.  This example would be better done with 'dcngettext()':
 
           if (groggy)
               message = dcngettext("%d customer disturbing me\n",
                                    "%d customers disturbing me\n",
                                    ncustomers, "adminprog")
           else
               message = dcngettext("enjoying %d customer\n",
                                    "enjoying %d customers\n",
                                    ncustomers, "adminprog")
           printf(message, ncustomers)
 
   4. During development, you might want to put the '.gmo' file in a
      private directory for testing.  This is done with the
      'bindtextdomain()' built-in function:
 
           BEGIN {
              TEXTDOMAIN = "guide"   # our text domain
              if (Testing) {
                  # where to find our files
                  bindtextdomain("testdir")
                  # joe is in charge of adminprog
                  bindtextdomain("../joe/testdir", "adminprog")
              }
              ...
           }
 
    SeeI18N Example for an example program showing the steps to
 create and use translations from 'awk'.
 
    ---------- Footnotes ----------
 
    (1) Thanks to Bruno Haible for this example.