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.

cfsetospeed — set output baud rate

#include <termios.h>
int cfsetospeed(struct termios *termios_p, speed_t speed);

The cfsetospeed() function shall set the output baud rate stored in the structure pointed to by termios_p to speed.

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. 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.

Upon successful completion, cfsetospeed() shall return 0; otherwise, it shall return -1 and errno may be set to indicate the error.

The cfsetospeed() function may fail if:

The speed value is not a valid baud rate.
The value of speed is outside the range of possible speed values as specified in <termios.h>.

The following sections are informative.



Refer to cfgetispeed().


cfgetispeed(), cfgetospeed(), cfsetispeed(), tcsetattr()

The Base Definitions volume of POSIX.1‐2017, Chapter 11, General Terminal Interface, <termios.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 .

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2017 IEEE/The Open Group