_TOLOWER(3P)

📦 version 2017a, in alpine 3.22, alpine 3.23, alpine 3.24, arch rolling, nixpkgs unstable, opensuse-leap 16.0

💖 _TOLOWER(3P) — the POSIX girlie's guide 💖

okay so bestie, we're looking at _tolower(3P) from the POSIX Programmer's Manual, and honestly? she's a little retro, a little deprecated, but she's still iconic. let's get into it 🦋

✨ PROLOG ✨

so like, real talk first: 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 go consult the corresponding Linux manual page for the actual deets on Linux behavior. OR, plot twist, the interface might not even be implemented on Linux at all. 🙈 no cap, check before you ship.

🌸 NAME 🌸

_tolower — transliterate uppercase characters to lowercase

that's it, that's the whole job. lowercase-ify your uppercase letters, nothing more 💅

🎀 SYNOPSIS 🎀

#include <ctype.h>

int _tolower(int c);

💜 DESCRIPTION 💜

okay so the _tolower() macro shall be equivalent to tolower(c) — except! and this is the important part, the ✨fine print✨ — the application shall ensure that the argument c is an uppercase letter.

so like. you're on your own to vibe-check your input before you hand it over. _tolower() is not here to babysit you. 🫶

⭐ RETURN VALUE ⭐

upon successful completion, _tolower() shall return the lowercase letter corresponding to the argument passed. she gives you back your letter, but tiny. lowercase era. 👑

🔥 ERRORS 🔥

No errors are defined.

and also, lowkey iconic of them to just say this — the following sections are informative.

🌈 EXAMPLES 🌈

None.

literally none. they didn't give us a single one. bestie we are on our own out here 😭 (but it's giving confident, honestly)

💅 APPLICATION USAGE 💅

applications should use the tolower() function instead of the obsolescent _tolower() function.

🚨 translation: _tolower() is obsolescent. like, old-school. she's giving vintage. use tolower() instead, fr fr.

🦋 RATIONALE 🦋

None.

they said no thoughts, head empty, no rationale. periodt. 💀

🌸 FUTURE DIRECTIONS 🌸

the _tolower() function may be removed in a future version.

🚨 so like, she might get cancelled. write your code accordingly bestie, don't build your whole personality around her.

🎀 SEE ALSO 🎀

  • tolower()
  • isupper()

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

okay so this is the part where we give credit, and we're gonna do it properly because we respect the elders:

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 bestie!! this one came to you from IEEE/The Open Group, 2017 — big thanks to the icons, we love them, we stan, no notes. now go use tolower() instead, okay? ily, bye!! 💖✨🎀
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