Behdad Esfahbod wrote: > Does it mean the same about iswdigit()? Yes. The ISO C 99 description of iswdigit(), section 7.25.2.1.5, is: "The iswdigit function tests for any wide character that corresponds to a decimal-digit character (as defined in 5.2.1)." See also the comment in glibc/localedata/gen-unicode-ctype.c function is_digit(). Bruno