ISWLOWER(3POSIX)

💖 ISWLOWER(3POSIX) 💖

okay bestie, welcome to the POSIX Programmer's Manual ✨ this one lives in section 3POSIX and it's literally all about checking if a wide character is lowercase. yes really. that's the whole vibe. 🎀

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🌸 PROLOG 🌸

so before we even get into it: this manual page is part of the POSIX Programmer's Manual. that's important, ok?

the Linux implementation of this interface may differ — so if you're on Linux, go consult the corresponding Linux manual page for the deets on Linux behavior. orrrr the interface might just not be implemented on Linux at all. 💀 either way, lowkey check first.

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✨ NAME ✨

iswlower, iswlower_l — test for a lowercase letter wide-character code 🦋

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👑 SYNOPSIS 👑

#include <wctype.h>

int iswlower(wint_t wc);
int iswlower_l(wint_t wc, locale_t locale);

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💅 DESCRIPTION 💅

okay so, for iswlower(): the functionality described on this reference page is aligned with the ISO C standard. if there's any conflict between the requirements described here and the ISO C standard, that conflict is unintentional — no cap. this volume of POSIX.1‐2017 defers to the ISO C standard. periodt.

the iswlower() and iswlower_l() functions shall test whether wc is a wide-character code representing a character of class lower in the current locale, or in the locale represented by locale, respectively. see the Base Definitions volume of POSIX.1‐2017, Chapter 7, Locale. 📖

the wc argument is a wint_t, and the value of it — the application shall ensure — is a wide-character code corresponding to a valid character in the locale used by the function, or equal to the value of the macro WEOF. if the argument has any other value, the behavior is undefined. 🚨 like, do not pass go, do not collect $200.

🫶 also: the behavior is undefined if the locale argument to iswlower_l() is the special locale object LC_GLOBAL_LOCALE, or if it's not a valid locale object handle. so... don't do that bestie.

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🌈 RETURN VALUE 🌈

iswlower() and iswlower_l() shall return non-zero if wc is a lowercase letter wide-character code. otherwise? they shall return 0. slay, simple as that. 💖

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💀 ERRORS 💀

no errors are defined. none. zero. iconic behavior honestly.

the following sections are informative. (so like, vibe-only, not rules.)

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🍓 EXAMPLES 🍓

None. 🙈

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🧚 APPLICATION USAGE 🧚

to ensure applications portability — especially across natural languages — only these functions and the functions in the reference pages listed in the SEE ALSO section should be used for character classification. that's the move. don't freestyle it. 💜

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⭐ RATIONALE ⭐

None.

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🦋 FUTURE DIRECTIONS 🦋

None.

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🔥 SEE ALSO 🔥

• iswalnum()
• iswalpha()
• iswcntrl()
• iswctype()
• iswdigit()
• iswgraph()
• iswprint()
• iswpunct()
• iswspace()
• iswupper()
• iswxdigit()
• setlocale()
• uselocale()1

The Base Definitions volume of POSIX.1‐2017, Chapter 7, Locale, <locale.h>, <wctype.h>

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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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and that's the whole page bestie 🎀 brought to you by IEEE/The Open Group, 2017, filing this one under ISWLOWER(3POSIX) 💅✨ go forth and classify your wide characters responsibly, ily 🫶