gnulib-local/lib/localcharset.c.diff

   1 Add a variant of `locale_charset' that returns its result based solely on
   2 information from the environment.  See
   3 http://lists.gnu.org/archive/html/guile-devel/2011-11/msg00040.html for the
   4 rationale.
   5
   6 --- a/lib/localcharset.c        2011-12-14 23:10:58.000000000 +0100
   7 +++ b/lib/localcharset.c        2011-12-15 00:45:12.000000000 +0100
   8 @@ -545,3 +545,74 @@ locale_charset (void)
   9
  10    return codeset;
  11  }
  12 +
  13 +/* A variant of the above, without calls to `setlocale', `nl_langinfo',
  14 +   etc.  */
  15 +const char *
  16 +environ_locale_charset (void)
  17 +{
  18 +  static char buf[2 + 10 + 1];
  19 +  const char *codeset, *aliases;
  20 +  const char *locale = NULL;
  21 +
  22 +  locale = getenv ("LC_ALL");
  23 +  if (locale == NULL || locale[0] == '\0')
  24 +    {
  25 +      locale = getenv ("LC_CTYPE");
  26 +      if (locale == NULL || locale[0] == '\0')
  27 +       locale = getenv ("LANG");
  28 +    }
  29 +
  30 +  if (locale != NULL && locale[0] != '\0')
  31 +    {
  32 +      /* If the locale name contains an encoding after the dot, return it.  */
  33 +      const char *dot = strchr (locale, '.');
  34 +
  35 +      if (dot != NULL)
  36 +        {
  37 +          const char *modifier;
  38 +
  39 +          dot++;
  40 +          /* Look for the possible @... trailer and remove it, if any.  */
  41 +          modifier = strchr (dot, '@');
  42 +          if (modifier == NULL)
  43 +            return dot;
  44 +          if (modifier - dot < sizeof (buf))
  45 +            {
  46 +              memcpy (buf, dot, modifier - dot);
  47 +              buf [modifier - dot] = '\0';
  48 +              return buf;
  49 +            }
  50 +        }
  51 +      else if (strcmp (locale, "C") == 0)
  52 +       {
  53 +         strcpy (buf, "ASCII");
  54 +         return buf;
  55 +       }
  56 +      else
  57 +       codeset = "";
  58 +    }
  59 +  else
  60 +    codeset = "";
  61 +
  62 +  /* Resolve alias. */
  63 +  for (aliases = get_charset_aliases ();
  64 +       *aliases != '\0';
  65 +       aliases += strlen (aliases) + 1, aliases += strlen (aliases) + 1)
  66 +    if (strcmp (codeset, aliases) == 0
  67 +        || (aliases[0] == '*' && aliases[1] == '\0'))
  68 +      {
  69 +        codeset = aliases + strlen (aliases) + 1;
  70 +        break;
  71 +      }
  72 +
  73 +  /* Don't return an empty string.  GNU libc and GNU libiconv interpret
  74 +     the empty string as denoting "the locale's character encoding",
  75 +     thus GNU libiconv would call this function a second time.  */
  76 +  if (codeset[0] == '\0')
  77 +    /* Default to Latin-1, for backward compatibility with Guile 1.8.  */
  78 +    codeset = "ISO-8859-1";
  79 +
  80 +  return codeset;
  81 +}