_TOLOWER(3POSIX)

📦 version 2017a, in debian bookworm, debian trixie, ubuntu jammy, ubuntu noble, ubuntu resolute, ubuntu stonking

💖 _TOLOWER(3POSIX) 💖

okay bestie, welcome to the POSIX Programmer's Manual — this little page is literally part of it. heads up tho: the Linux implementation of this interface may differ (so pls consult the corresponding Linux manual page for details on Linux behavior), or like… the interface might not even be implemented on Linux at all. 🙈 vibe check accordingly.

✨ NAME ✨

_tolower — transliterate uppercase characters to lowercase 💅

🦋 SYNOPSIS 🦋

#include <ctype.h>

int _tolower(int c);

🌸 DESCRIPTION 🌸

so the _tolower() macro shall be equivalent to tolower(c), with one tiny little catch: the application shall ensure that the argument c is an uppercase letter. that's the whole deal. no cap. 👑

⭐ RETURN VALUE ⭐

upon successful completion, _tolower() shall return the lowercase letter corresponding to the argument passed. slay. that's it, that's the return. 🎀

💀 ERRORS 💀

no errors are defined. like, none. not a single one.

the following sections are informative. (yes bestie, that's what it says, we're just relaying the lore 📜)

🌈 EXAMPLES 🌈

None. 😭 (iconic of them honestly)

🫶 APPLICATION USAGE 🫶

applications should use the tolower() function instead of the obsolescent _tolower() function. fr fr, tolower() is the main character here — _tolower() is giving retired legend energy. 👑

🧚 RATIONALE 🧚

None.

🔮 FUTURE DIRECTIONS 🔮

the _tolower() function may be removed in a future version. ⚠️ so like, don't build your whole personality around it, bestie.

👀 SEE ALSO 👀

  • tolower()
  • isupper()

also: The Base Definitions volume of POSIX.1‐2017, Chapter 7, Locale, <ctype.h> 🦋

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 .

and that's the whole page, babe 💖 go forth and lowercase responsibly. IEEE/The Open Group, 2017 — mwah, catch u in the next man page ✨💅
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