ISWCTYPE(3P) POSIX Programmer's Manual ISWCTYPE(3P)PROLOG
This manual page is part of the POSIX Programmer's Manual. The Linux
implementation of this interface may differ (consult the corresponding
Linux manual page for details of Linux behavior), or the interface may
not be implemented on Linux.
NAMEiswctype - test character for a specified class
SYNOPSIS
#include <wctype.h>
int iswctype(wint_t wc, wctype_t charclass);
DESCRIPTION
The iswctype() function shall determine 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 corre‐
sponding to the valid character encodings in the current locale. If the
wc argument is not in the domain of the function, the result is unde‐
fined. If the value of charclass is invalid (that is, not obtained by a
call to wctype() or charclass is invalidated by a subsequent call to
setlocale() that has affected category LC_CTYPE ) the result is unspec‐
ified.
RETURN VALUE
The iswctype() function shall return non-zero (true) if and only if wc
has the property described by charclass. If charclass is 0, iswctype()
shall return 0.
ERRORS
No errors are defined.
The following sections are informative.
EXAMPLES
Testing for a Valid Character
#include <wctype.h>
...
int yes_or_no;
wint_t wc;
wctype_t valid_class;
...
if ((valid_class=wctype("vowel")) == (wctype_t)0)
/* Invalid character class. */
yes_or_no=iswctype(wc,valid_class);
APPLICATION USAGE
The twelve strings "alnum", "alpha", "blank", "cntrl", "digit",
"graph", "lower", "print", "punct", "space", "upper", and "xdigit" are
reserved for the standard character classes. 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"))
iswblank(wc) iswctype(wc, wctype("blank"))
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"))
RATIONALE
None.
FUTURE DIRECTIONS
None.
SEE ALSOiswalnum(), iswalpha(), iswcntrl(), iswdigit(), iswgraph(), iswlower(),
iswprint(), iswpunct(), iswspace(), iswupper(), iswxdigit(), setlo‐
cale(), wctype(), the Base Definitions volume of IEEE Std 1003.1-2001,
<wchar.h>, <wctype.h>
COPYRIGHT
Portions of this text are reprinted and reproduced in electronic form
from IEEE Std 1003.1, 2003 Edition, Standard for Information Technology
-- Portable Operating System Interface (POSIX), The Open Group Base
Specifications Issue 6, Copyright (C) 2001-2003 by the Institute of
Electrical and Electronics Engineers, Inc and The Open Group. In the
event of any discrepancy between this version and the original IEEE and
The Open Group Standard, the original IEEE and The Open Group Standard
is the referee document. The original Standard can be obtained online
at http://www.opengroup.org/unix/online.html .
IEEE/The Open Group 2003 ISWCTYPE(3P)
