Function is_hex

cppcryptfsctl/cppcryptfsctl.cpp:127–130

}

static bool is_hex(wint_t c) 
{
    return iswdigit(c) || (c >= L'a' && c <= L'f') || (c >= L'A' && c <= L'F');
}

static int do_self_args(int argc, wchar_t* const argv[])
{