iswctype(3p) — Linux manual page
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.
NAME
iswctype, iswctype_l — test character for a specified class
SYNOPSIS
#include <wctype.h>
int iswctype(wint_t wc, wctype_t charclass);
int iswctype_l(wint_t wc, wctype_t charclass,
locale_t locale);
DESCRIPTION
For iswctype(): The functionality described on this reference
page is aligned with the ISO C standard. Any conflict between the
requirements described here and the ISO C standard is
unintentional. This volume of POSIX.1‐2017 defers to the ISO C
standard.
The iswctype() and iswctype_l() functions shall determine whether
the wide-character code wc has the character class charclass,
returning true or false. The iswctype() and iswctype_l()
functions are defined on WEOF and wide-character codes
corresponding to the valid character encodings in the current
locale, or in the locale represented by locale, respectively. 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() or charclass is invalidated by a
subsequent call to setlocale() that has affected category
LC_CTYPE) the result is unspecified.
The behavior is undefined if the locale argument to iswctype_l()
is the special locale object LC_GLOBAL_LOCALE or is not a valid
locale object handle.
RETURN VALUE
The iswctype() and iswctype_l() functions shall return non-zero
(true) if and only if wc has the property described by charclass.
If charclass is (wctype_t)0, these functions 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"))
iswalnum_l(wc, locale) iswctype_l(wc, wctype("alnum"), locale)
iswalpha(wc) iswctype(wc, wctype("alpha"))
iswalpha_l(wc, locale) iswctype_l(wc, wctype("alpha"), locale)
iswblank(wc) iswctype(wc, wctype("blank"))
iswblank_l(wc, locale) iswctype_l(wc, wctype("blank"), locale)
iswcntrl(wc) iswctype(wc, wctype("cntrl"))
iswcntrl_l(wc, locale) iswctype_l(wc, wctype("cntrl"), locale)
iswdigit(wc) iswctype(wc, wctype("digit"))
iswdigit_l(wc, locale) iswctype_l(wc, wctype("digit"), locale)
iswgraph(wc) iswctype(wc, wctype("graph"))
iswgraph_l(wc, locale) iswctype_l(wc, wctype("graph"), locale)
iswlower(wc) iswctype(wc, wctype("lower"))
iswlower_l(wc, locale) iswctype_l(wc, wctype("lower"), locale)
iswprint(wc) iswctype(wc, wctype("print"))
iswprint_l(wc, locale) iswctype_l(wc, wctype("print"), locale)
iswpunct(wc) iswctype(wc, wctype("punct"))
iswpunct_l(wc, locale) iswctype_l(wc, wctype("punct"), locale)
iswspace(wc) iswctype(wc, wctype("space"))
iswspace_l(wc, locale) iswctype_l(wc, wctype("space"), locale)
iswupper(wc) iswctype(wc, wctype("upper"))
iswupper_l(wc, locale) iswctype_l(wc, wctype("upper"), locale)
iswxdigit(wc) iswctype(wc, wctype("xdigit"))
iswxdigit_l(wc, locale) iswctype_l(wc, wctype("xdigit"), locale)
RATIONALE
None.
FUTURE DIRECTIONS
None.
SEE ALSO
iswalnum(3p), iswalpha(3p), iswcntrl(3p), iswdigit(3p),
iswgraph(3p), iswlower(3p), iswprint(3p), iswpunct(3p),
iswspace(3p), iswupper(3p), iswxdigit(3p), setlocale(3p),
uselocale(3p), wctype(3p)
The Base Definitions volume of POSIX.1‐2017, locale.h(0p),
wctype.h(0p)
COPYRIGHT
Portions of this text are reprinted and reproduced in electronic
form from IEEE Std 1003.1-2017, Standard for Information
Technology -- Portable Operating System Interface (POSIX), The
Open Group Base Specifications Issue 7, 2018 Edition, Copyright
(C) 2018 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 .
Any typographical or formatting errors that appear in this page
are most likely to have been introduced during the conversion of
the source files to man page format. To report such errors, see
https://www.kernel.org/doc/man-pages/reporting_bugs.html .
IEEE/The Open Group 2017 ISWCTYPE(3P)
Pages that refer to this page: wchar.h(0p), wctype.h(0p), iswalnum(3p), iswalpha(3p), iswblank(3p), iswcntrl(3p), iswdigit(3p), iswgraph(3p), iswlower(3p), iswprint(3p), iswpunct(3p), iswspace(3p), iswupper(3p), iswxdigit(3p), setlocale(3p), wctype(3p)