ISWLOWER(3P)

💖 ISWLOWER(3P) — POSIX Programmer's Manual 💖

okay bestie, welcome to the group chat. this one lives in the POSIX Programmer's Manual (that's the manual name, slay), and it's all about testing whether a wide-character code is lowercase. very demure, very mindful, very useful. let's get into it 🦋

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🎀 PROLOG 🎀

heads up, bestie: this manual page is part of the POSIX Programmer's Manual. The Linux implementation of this interface may differ — so if you're on Linux, pls consult the corresponding Linux manual page for the deets on Linux behavior. Or, plot twist, the interface might not even be implemented on Linux at all. 🙈

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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 💅

For iswlower(): 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 — no drama intended, fr fr. This volume of POSIX.1‐2017 defers to the ISO C standard. 👑

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 — that's where the locale lore lives, iykyk.

The wc argument is a wint_t, and the value of it — the application shall ensure it 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. 🫣 so like, don't do that. not me playing fast and loose with undefined behavior...

⚠️ WARNING ⚠️ The behavior is undefined if the locale argument to iswlower_l() is the special locale object LC_GLOBAL_LOCALE, or is not a valid locale object handle. So keep those handles valid, bestie, or it's giving chaos. 💀

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🌈 RETURN VALUE 🌈

The iswlower() and iswlower_l() functions shall return non-zero if wc is a lowercase letter wide-character code; otherwise, they shall return 0. Simple as. ✨

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🍓 ERRORS 🍓

No errors are defined. iconic, honestly — nothing to report.

The following sections are informative.

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🧚 EXAMPLES 🧚

None. we're keeping it mysterious. 💜

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🦋 APPLICATION USAGE 🦋

To ensure applications portability — especially across natural languages, which is the whole vibe — only these functions and the functions in the reference pages listed in the SEE ALSO section should be used for character classification. Don't get creative with it, bestie. stay in your lane, stay portable. 🫶

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👑 RATIONALE 👑

None. no notes. periodt.

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⭐ FUTURE DIRECTIONS ⭐

None. the future is, apparently, unchanged. we love stability. 💖

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🔥 SEE ALSO 🔥

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

Also on the reading list, bestie: The Base Definitions volume of POSIX.1‐2017, Chapter 7, Locale, plus <locale.h> and <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 — it's the main character here, no cap. 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!! 🎀 this one came to you courtesy of IEEE/The Open Group, 2017 — mwah, go test some wide chars, ily 💖✨