TCSETATTR(3)                         BSD                          TCSETATTR(3)



NAME
     tcsetattr - Set the arguments associated with the terminal

SYNOPSIS
     #include <termios.h>

     int tcsetattr (filedes, optional_actions, termios_p)
     int filedes, optional_actions;
     const struct termios *termios_p;

DESCRIPTION
     The tcsetattr function sets the arguments associated with the terminal
     referred to by the open file descriptor (an open file descriptor
     associated with a terminal) from the termios structure referenced by
     termios_p as follows:

     +    If optional_actions is TCSANOW, the change will occur immediately.

     +    If optional_actions is TCSADRAIN, the change will occur after all
          output written to filedes has been transmitted. This function should
          be used when changing arguments that affect output.

     +    If optional_actions is TCSAFLUSH, the change will occur after all
          output written to filedes has been transmitted, and all input so far
          received but not read will be discarded before the change is made.

     If the output baud rate stored in the termios structure pointed to by the
     termios_p argument is the zero baud rate, B0, the modem control lines
     will no longer be asserted.  Normally, this will disconnect the line.

     The following behavior is obsolescent; you should not rely on this
     behavior:

          If the input baud rate stored in the termios structure pointed to by
          the termios_p argument is zero, the input baud rate given to the
          hardware will be the same as the output baud rate stored in the
          termios structure.

     Attempts to use tcsetattr from a process that is a member of a background
     process group on a filedes associated with its controlling terminal
     causes the process group to be sent a SIGTTOU signal.  If the calling
     process is blocking or ignoring SIGTTOU signals, the process is allowed
     to perform the operation and no signal is sent.

DIAGNOSTICS
     Upon successful completion, 0 (zero) is returned. Otherwise, -1 is
     returned and errno is set to indicate the error.

ERRORS
     If the tcsetattr function fails, errno will be set to one of the
     following values:

     [EBADF]   The filedes argument is not a valid file descriptor.

     [EINVAL]  The optional_actions argument is not a proper value, or an
               attempt was made to change an attribute represented in the
               termios structure to an unsupported value.

     [ENOTTY]  The file associated with the filedes argument is not a
               terminal.

     [EINTR]   A signal interrupted the tcsetattr function.

SEE ALSO
     cfgetispeed(3), tcgetattr(3)