#include <termios.h> int cfsetispeed(struct termios *termios_p, speed_t speed);
int cfsetospeed(struct termios *termios_p, speed_t speed);
The cfsetispeed() function sets the input baud rate stored in the structure pointed to by termios_p to speed.
The cfsetospeed() function sets the output baud rate stored in the structure pointed to by termios_p to speed.
There is no effect on the baud rates set in the hardware until a subsequent successful call to tcsetattr(3C) on the same termios structure.
Upon successful completion, cfsetispeed() and cfsetospeed() return 0. Otherwise −1 is returned, and errno may be set to indicate the error.
The cfsetispeed() and cfsetospeed() functions 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>.
See attributes(5) for descriptions of the following attributes: