wctype.h(0P)

✨ wctype.h(0P) — the wide-char glow-up header ✨

ok so bestie, we're in the POSIX Programmer's Manual today and the star of the show is wctype.h, the header that handles wide-character classification and mapping utilities. 💖 It's giving main character energy for every wide char that needs to know what it is.

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🚨 PROLOG 🚨

ngl, this is the part where the legal girlies do their thing. 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.

fr fr, read the Linux page too. don't come for me if Linux does its own thing. 💀

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🌸 NAME 🌸

wctype.h — wide-character classification and mapping utilities

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🎀 SYNOPSIS 🎀

#include <wctype.h>

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💅 DESCRIPTION 💅

okay so some of the functionality described on this reference page extends the ISO C standard. Applications shall define the appropriate feature test macro (see the System Interfaces volume of POSIX.1‐2017, Section 2.2, The Compilation Environment) to enable the visibility of these symbols in this header. like, the ✨extra✨ stuff doesn't just show up for free, you have to ask for it.

The <wctype.h> header shall define the following types:

• wint_t — as described in <wchar.h>. 🫶
• wctrans_t — a scalar type that can hold values which represent locale-specific character mappings.
• wctype_t — as described in <wchar.h>.

The <wctype.h> header shall define the locale_t type as described in <locale.h>.

The <wctype.h> header shall define the following macro:

• WEOF — as described in <wchar.h>.

For all functions described in this header that accept an argument of type wint_t, the value is representable as a wchar_t or equals the value of WEOF. If this argument has any other value, the behavior is undefined. 😭 bestie do NOT pass random garbage in there, it's undefined behavior and the vibes will be rancid.

The behavior of these functions shall be affected by the LC_CTYPE category of the current locale. yes, your locale is literally running the show here. 🌍

Inclusion of the <wctype.h> header may make visible all symbols from the headers <ctype.h>, <stdarg.h>, <stddef.h>, <stdio.h>, <stdlib.h>, <string.h>, <time.h>, and <wchar.h>. it's giving "brings the whole friend group to the function". 👯

The following shall be declared as functions and may also be defined as macros. Function prototypes shall be provided for use with ISO C standard compilers.

int       iswalnum(wint_t);
int       iswalnum_l(wint_t, locale_t);
int       iswalpha(wint_t);
int       iswalpha_l(wint_t, locale_t);
int       iswblank(wint_t);
int       iswblank_l(wint_t, locale_t);
int       iswcntrl(wint_t);
int       iswcntrl_l(wint_t, locale_t);
int       iswctype(wint_t, wctype_t);
int       iswctype_l(wint_t, wctype_t, locale_t);
int       iswdigit(wint_t);
int       iswdigit_l(wint_t, locale_t);
int       iswgraph(wint_t);
int       iswgraph_l(wint_t, locale_t);
int       iswlower(wint_t);
int       iswlower_l(wint_t, locale_t);
int       iswprint(wint_t);
int       iswprint_l(wint_t, locale_t);
int       iswpunct(wint_t);
int       iswpunct_l(wint_t, locale_t);
int       iswspace(wint_t);
int       iswspace_l(wint_t, locale_t);
int       iswupper(wint_t);
int       iswupper_l(wint_t, locale_t);
int       iswxdigit(wint_t);
int       iswxdigit_l(wint_t, locale_t);
wint_t    towctrans(wint_t, wctrans_t);
wint_t    towctrans_l(wint_t, wctrans_t, locale_t);
wint_t    towlower(wint_t);
wint_t    towlower_l(wint_t, locale_t);
wint_t    towupper(wint_t);
wint_t    towupper_l(wint_t, locale_t);
wctrans_t wctrans(const char *);
wctrans_t wctrans_l(const char *, locale_t);
wctype_t  wctype(const char *);
wctype_t  wctype_l(const char *, locale_t);

The following sections are informative. (iykyk, that means they're the commentary track, not the rules. 🎧)

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🌈 APPLICATION USAGE 🌈

None. literally nothing. the slayest section to write. ✨

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💜 RATIONALE 💜

None. also nothing. we love a low-effort era. 💅

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🦋 FUTURE DIRECTIONS 🦋

None. no notes, no changes coming, periodt. 👑

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🔥 SEE ALSO 🔥

• <ctype.h>, <locale.h>, <stdarg.h>, <stddef.h>, <stdio.h>, <stdlib.h>, <string.h>, <time.h>, <wchar.h>
• The System Interfaces volume of POSIX.1‐2017, Section 2.2, The Compilation Environment, iswalnum(), iswalpha(), iswblank(), iswcntrl(), iswctype(), iswdigit(), iswgraph(), iswlower(), iswprint(), iswpunct(), iswspace(), iswupper(), iswxdigit(), setlocale(), towctrans(), towlower(), towupper(), wctrans(), wctype()

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📜 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 .

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okay that's the whole page bestie, we ate and left no crumbs 🍓💖 this diva came to you from IEEE/The Open Group, 2017, and wctype.h(0P) is officially out. mwah. 💋