X-Git-Url: http://erislabs.net/gitweb/?a=blobdiff_plain;f=doc%2Fposix-functions%2Fisxdigit.texi;h=cc6133c8204d4db01557839c21d083ad343ba6fd;hb=54b5ce0e1a4f6a4af37f970e45e6e173e5b0a1c6;hp=e03106c945130a029d85030784b4a4a9e5d51b0c;hpb=09ef7461110822a3970aa8eebcfaa740996a82f2;p=gnulib.git

diff --git a/doc/posix-functions/isxdigit.texi b/doc/posix-functions/isxdigit.texi
index e03106c94..cc6133c82 100644
--- a/doc/posix-functions/isxdigit.texi
+++ b/doc/posix-functions/isxdigit.texi
@@ -13,3 +13,28 @@ Portability problems fixed by Gnulib:
 Portability problems not fixed by Gnulib:
 @itemize
 @end itemize
+
+Note: This function's behaviour depends on the locale, but does not support
+the multibyte characters that occur in strings in locales with
+@code{MB_CUR_MAX > 1} (this includes all the common UTF-8 locales).
+There are four alternative APIs:
+
+@table @code
+@item c_isxdigit
+This function operates in a locale independent way and returns true only for
+ASCII characters.  It is provided by the Gnulib module @samp{c-ctype}.
+
+@item iswxdigit
+This function operates in a locale dependent way, on wide characters.  In
+order to use it, you first have to convert from multibyte to wide characters,
+using the @code{mbrtowc} function.  It is provided by the Gnulib module
+@samp{wctype}.
+
+@item mb_isxdigit
+This function operates in a locale dependent way, on multibyte characters.
+It is provided by the Gnulib module @samp{mbchar}.
+
+@item uc_is_xdigit
+This function operates in a locale independent way, on Unicode characters.
+It is provided by the Gnulib module @samp{unictype/ctype-xdigit}.
+@end table