cfsetispeed -- Set Input Baud Rate

SYNOPSIS

 #include <termios.h>


 int cfsetispeed(struct termios *terminal, speed_t speed);

DESCRIPTION

cfsetispeed is used to set a new input baud rate in the termios structure pointed to by terminal. This structure is defined in <termios.h> and contains terminal attribute information.

The tcgetattr function must be used to obtain a copy of the termios structure before you can use the cfsetispeed function to set the input baud rate. The cfsetispeed function changes the baud rate in this copy and the tcsetattr functions can then be used to update the termios control structure.

The defined type, speed_t, specifies the baud rate. Each value is associated with an asynchronous line speed as follows:

   Return Value    Baud Rate

   B0              hang up

   B50             50 baud

   B75             75 baud

   B110            110 baud

   B134            134.5 baud

   B150            150 baud

   B200            200 baud

   B300            300 baud

   B600            600 baud

   B1200           1200 baud

   B1800           1800 baud

   B2400           2400 baud

   B4800           4800 baud

   B9600           9600 baud

   B19200          19,200 baud

   B38400          38,400 baud

RETURN VALUE

If successful, cfsetispeed returns 0. A -1 is returned if unsuccessful.

PORTABILITY

The cfsetispeed function is defined by the POSIX.1 standard and provides portability between operating environments. Note that OpenEdition only supports pseudoterminals and that baud rate does not affect the operation of a pseudoterminal.

EXAMPLE

The following example illustrates the use of cfsetispeed to set a new output baud rate:

  #include <sys/types.h>
  #include <termios.h>
  #include <unistd.h>

  main()
  {
     struct termios termAttr;
     speed_t baudRate;

        /* Make a copy of the termios structure. */
     tcgetattr(STDIN_FILENO, &termAttr);
        /* Get the input speed.                  */
     baudRate = cfgetispeed(&termAttr);
        /* Set output speed if not 9600 baud.    */
     if (baudRate != B9600) {
        cfsetispeed(&termAttr, B9600);
        tcsetattr(STDIN_FILENO, TCSANOW, &termAttr);
     }
  }

RELATED FUNCTIONS

cfgetispeed, cfsetospeed, tcsetattr