#include <wchar.h>
int iswctype(wint_t wc, wctype_t charclass);
The iswctype() function determines whether the wide-character code wc has the character class charclass, returning TRUE or FALSE. The iswctype() function is defined on WEOF and wide-character codes corresponding to the valid character encodings in the current locale. If the wc argument is not in the domain of the function, the result is undefined. If the value of charclass is invalid (that is, not obtained by a call to wctype(3C) or charclass is invalidated by a subsequent call to setlocale(3C) that has affected category LC_CTYPE), the result is indeterminate.
The iswctype() function returns 0 for FALSE and non-zero for TRUE.
There are twelve strings that are reserved for the standard character classes:
| "alnum" | "alpha" | "blank" |
| "cntrl" | "digit" | "graph" |
| "lower" | "print" | "punct" |
| "space" | "upper" | "xdigit" |
In the table below, the functions in the left column are equivalent to the functions in the right column.
| iswalnum(wc) | iswctype(wc, wctype("alnum")) |
| iswalpha(wc) | iswctype(wc, wctype("alpha")) |
| iswcntrl(wc) | iswctype(wc, wctype("cntrl")) |
| iswdigit( wc) | iswctype(wc, wctype("digit")) |
| iswgraph(wc) | iswctype(wc, wctype("graph")) |
| iswlower(wc) | iswctype(wc, wctype("lower")) |
| iswprint(wc) | iswctype(wc, wctype("print")) |
| iswpunct(wc) | iswctype( wc, wctype("punct")) |
| iswspace(wc) | iswctype(wc, wctype("space")) |
| iswupper(wc) | iswctype(wc, wctype("upper")) |
| iswxdigit(wc) | iswctype(wc, wctype("xdigit")) |
The call
does not have an equivalent isw*() function.
See attributes(5) for descriptions of the following attributes:
| ATTRIBUTE TYPE | ATTRIBUTE VALUE |
| CSI | Enabled |
| Interface Stability | Standard |
| MT-Level | MT-Safe with exceptions |
iswalpha(3C), setlocale(3C), wctype(3C), attributes(5), environ(5), standards(5)