ISWALNUM(3) Library Functions Manual ISWALNUM(3)

iswalnum, iswalpha, iswascii, iswblank, iswcntrl, iswdigit, iswgraph, iswhexnumber, iswideogram, iswlower, iswnumber, iswphonogram, iswprint, iswpunct, iswrune, iswspace, iswspecial, iswupper, iswxdigitwide character classification utilities

Standard C Library (libc, -lc)

#include <wctype.h>

int
iswalnum(wint_t wc);

int
iswalpha(wint_t wc);

int
iswascii(wint_t wc);

int
iswblank(wint_t wc);

int
iswcntrl(wint_t wc);

int
iswdigit(wint_t wc);

int
iswgraph(wint_t wc);

int
iswhexnumber(wint_t wc);

int
iswideogram(wint_t wc);

int
iswlower(wint_t wc);

int
iswnumber(wint_t wc);

int
iswphonogram(wint_t wc);

int
iswprint(wint_t wc);

int
iswpunct(wint_t wc);

int
iswrune(wint_t wc);

int
iswspace(wint_t wc);

int
iswspecial(wint_t wc);

int
iswupper(wint_t wc);

int
iswxdigit(wint_t wc);

The above functions are character classification utility functions, for use with wide characters (wchar_t or wint_t). See the description for the similarly-named single byte classification functions (such as isalnum(3)), for details.

Extended locale versions of these functions are documented in iswalnum_l(3). See xlocale(3) for more information.

The functions return zero if the character tests false and return non-zero if the character tests true.

isalnum(3), isalpha(3), isascii(3), isblank(3), iscntrl(3), isdigit(3), isgraph(3), ishexnumber(3), isideogram(3), islower(3), isnumber(3), isphonogram(3), isprint(3), ispunct(3), isrune(3), isspace(3), isspecial(3), isupper(3), iswalnum_l(3), isxdigit(3), wctype(3)

These functions conform to IEEE Std 1003.1-2001 (“POSIX.1”), except iswascii(), iswhexnumber(), iswideogram(), iswnumber(), iswphonogram(), iswrune(), and iswspecial(), which are FreeBSD extensions.

The result of these functions is undefined unless the argument is WEOF or a valid wchar_t value for the current locale.

October 3, 2002 macOS 14.6