1ISWCTYPE(3P) POSIX Programmer's Manual ISWCTYPE(3P)
2
6 This manual page is part of the POSIX Programmer's Manual. The Linux
7 implementation of this interface may differ (consult the corresponding
8 Linux manual page for details of Linux behavior), or the interface may
9 not be implemented on Linux.
10
12 iswctype, iswctype_l — test character for a specified class
13
15 #include <wctype.h>
16 int iswctype(wint_t wc, wctype_t charclass);
18 int iswctype_l(wint_t wc, wctype_t charclass,
19 locale_t locale);
20
22 For iswctype(): The functionality described on this reference page is
23 aligned with the ISO C standard. Any conflict between the requirements
24 described here and the ISO C standard is unintentional. This volume of
25 POSIX.1‐2017 defers to the ISO C standard.
26 The iswctype() and iswctype_l() functions shall determine whether the
28 wide-character code wc has the character class charclass, returning
29 true or false. The iswctype() and iswctype_l() functions are defined on
30 WEOF and wide-character codes corresponding to the valid character
31 encodings in the current locale, or in the locale represented by
32 locale, respectively. If the wc argument is not in the domain of the
33 function, the result is undefined. If the value of charclass is
34 invalid (that is, not obtained by a call to wctype() or charclass is
35 invalidated by a subsequent call to setlocale() that has affected cate‐
36 gory LC_CTYPE) the result is unspecified.
37 The behavior is undefined if the locale argument to iswctype_l() is the
39 special locale object LC_GLOBAL_LOCALE or is not a valid locale object
40 handle.
41
43 The iswctype() and iswctype_l() functions shall return non-zero (true)
44 if and only if wc has the property described by charclass. If char‐
45 class is (wctype_t)0, these functions shall return 0.
46
48 No errors are defined.
49 The following sections are informative.
51
53 Testing for a Valid Character
54 #include <wctype.h>
55 ...
56 int yes_or_no;
57 wint_t wc;
58 wctype_t valid_class;
59 ...
60 if ((valid_class=wctype("vowel")) == (wctype_t)0)
61 /* Invalid character class. */
62 yes_or_no=iswctype(wc,valid_class);
63
65 The twelve strings "alnum", "alpha", "blank", "cntrl", "digit",
66 "graph", "lower", "print", "punct", "space", "upper", and "xdigit" are
67 reserved for the standard character classes. In the table below, the
68 functions in the left column are equivalent to the functions in the
69 right column.
70 iswalnum(wc) iswctype(wc, wctype("alnum"))
73 iswalnum_l(wc, locale) iswctype_l(wc, wctype("alnum"), locale)
74 iswalpha(wc) iswctype(wc, wctype("alpha"))
75 iswalpha_l(wc, locale) iswctype_l(wc, wctype("alpha"), locale)
76 iswblank(wc) iswctype(wc, wctype("blank"))
77 iswblank_l(wc, locale) iswctype_l(wc, wctype("blank"), locale)
78 iswcntrl(wc) iswctype(wc, wctype("cntrl"))
79 iswcntrl_l(wc, locale) iswctype_l(wc, wctype("cntrl"), locale)
80 iswdigit(wc) iswctype(wc, wctype("digit"))
81 iswdigit_l(wc, locale) iswctype_l(wc, wctype("digit"), locale)
82 iswgraph(wc) iswctype(wc, wctype("graph"))
83 iswgraph_l(wc, locale) iswctype_l(wc, wctype("graph"), locale)
84 iswlower(wc) iswctype(wc, wctype("lower"))
85 iswlower_l(wc, locale) iswctype_l(wc, wctype("lower"), locale)
86 iswprint(wc) iswctype(wc, wctype("print"))
87 iswprint_l(wc, locale) iswctype_l(wc, wctype("print"), locale)
88 iswpunct(wc) iswctype(wc, wctype("punct"))
89 iswpunct_l(wc, locale) iswctype_l(wc, wctype("punct"), locale)
90 iswspace(wc) iswctype(wc, wctype("space"))
91 iswspace_l(wc, locale) iswctype_l(wc, wctype("space"), locale)
92 iswupper(wc) iswctype(wc, wctype("upper"))
93 iswupper_l(wc, locale) iswctype_l(wc, wctype("upper"), locale)
94 iswxdigit(wc) iswctype(wc, wctype("xdigit"))
95 iswxdigit_l(wc, locale) iswctype_l(wc, wctype("xdigit"), locale)
96
98 None.
99
101 None.
102
104 iswalnum(), iswalpha(), iswcntrl(), iswdigit(), iswgraph(), iswlower(),
105 iswprint(), iswpunct(), iswspace(), iswupper(), iswxdigit(), setlo‐
106 cale(), uselocale(), wctype()
107 The Base Definitions volume of POSIX.1‐2017, <locale.h>, <wctype.h>
109
111 Portions of this text are reprinted and reproduced in electronic form
112 from IEEE Std 1003.1-2017, Standard for Information Technology -- Por‐
113 table Operating System Interface (POSIX), The Open Group Base Specifi‐
114 cations Issue 7, 2018 Edition, Copyright (C) 2018 by the Institute of
115 Electrical and Electronics Engineers, Inc and The Open Group. In the
116 event of any discrepancy between this version and the original IEEE and
117 The Open Group Standard, the original IEEE and The Open Group Standard
118 is the referee document. The original Standard can be obtained online
119 at http://www.opengroup.org/unix/online.html .
120 Any typographical or formatting errors that appear in this page are
122 most likely to have been introduced during the conversion of the source
123 files to man page format. To report such errors, see https://www.ker‐
124 nel.org/doc/man-pages/reporting_bugs.html .
125IEEE/The Open Group 2017 ISWCTYPE(3P)