CFSETOSPEED(3POSIX)

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

💅 CFSETOSPEED — the 3POSIX page, bestie edition ✨

okay so real quick before we dive in: this is part of the POSIX Programmer's Manual, and the Linux implementation of this interface may differ (so go peek at the corresponding Linux manual page if you want the Linux tea ☕). Or — plot twist — the interface might not even be implemented on Linux at all. 🙈

🌸 PROLOG 🌸

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. iykyk 💀

🎀 NAME 🎀

cfsetospeed — set output baud rate ✨

🦋 SYNOPSIS 🦋

#include <termios.h>

int cfsetospeed(struct termios *termios_p, speed_t speed);

💖 DESCRIPTION 💖

So the cfsetospeed() function shall set the output baud rate stored in the structure pointed to by termios_p to speed. That's it, that's the whole job. 💅

But wait — there's a vibe check here, and it's important. There shall be no effect on the baud rates set in the hardware until a subsequent successful call to tcsetattr() with the same termios structure. So like, you're not actually changing the hardware yet, you're just writing down your intentions. manifesting ✨

Similarly, errors resulting from attempts to set baud rates not supported by the terminal device need not be detected until the tcsetattr() function is called. so yeah, it might not tell you something's wrong until later. not me finding out at the worst possible moment 😭

⭐ RETURN VALUE ⭐

  • Upon successful completion, cfsetospeed() shall return 0 — slay 💖
  • Otherwise, it shall return -1 and errno may be set to indicate the error. 🫠

🔥 ERRORS 🔥

The cfsetospeed() function may fail if:

  • EINVAL — The speed value is not a valid baud rate. 🚫
  • EINVAL — The value of speed is outside the range of possible speed values as specified in <termios.h>. 📉
heads up bestie: both of those are EINVAL, so if you see it, you got two possible stories and neither one is cute. 💀

The following sections are informative.

🧚 EXAMPLES 🧚

None. 😶 (yeah, we're on our own here)

🌈 APPLICATION USAGE 🌈

None. 🫶

👑 RATIONALE 👑

Refer to cfgetispeed(). (go read that one, it's got the lore 📖)

🌟 FUTURE DIRECTIONS 🌟

None. ✨

💜 SEE ALSO 💜

  • cfgetispeed()
  • cfgetospeed()
  • cfsetispeed()
  • tcsetattr()

The Base Definitions volume of POSIX.1‐2017, Chapter 11, General Terminal Interface, <termios.h> — yes, go read the chapter, it's giving academic 🎓

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 🫶 — brought to you by IEEE/The Open Group, dated 2017, filed under CFSETOSPEED(3POSIX) in the POSIX Programmer's Manual. go set some baud rates, you absolute icon 💅✨

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