The ctype.h header file declares functions used in character classification. The functions declared are:
isalnum() | isalpha() | isblank() | iscntrl() | isdigit() |
isgraph() | islower() | isprint() | ispunct() | isspace() |
isupper() | isxdigit() | tolower() | toupper() |
_XOPEN_SOURCE
isascii() | toascii() | _tolower() | _toupper() |
For more information about the effect of locale, see setlocale(), locale.h, or look up the individual functions in this topic. For still more information, see "Internationalization: Locales and Character Sets" in z/OS XL C/C++ Programming Guide.