nextwctype - "iterate through character classes"
Library Synopsis Description Return Values See Also
.In wctype.h wint_t nextwctype "wint_t ch" "wctype_t wct"
The nextwctype function determines the next character after ch that is a member of character class wct. If ch is -1, the search begins at the first member of wct.
The nextwctype functions returns the next character, or -1 if there are no more.