Terminal device control

General terminal interface

Terminal Device Control functions offer a general terminal interface for controlling asynchronous communication-ports in a device-independent manner using parameters stored in the termios structure which is defined by the <termios.h> header file (see termio(7)). UNIX System V also uses termios to control the operation of network-connections.

Terminal device control functions

Function Description
cfgetospeed get output baud-rate
cfsetospeed set output baud-rate
cfgetispeed get input baud-rate
cfsetispeed set input baud-rate
tcgetattr get state of terminal
tcsetattr set state of terminal
tcsendbreak line control function
tcdrain line control function
tcflush line control function
tcflow line control function
tcgetpgrp get foreground process-group-id
tcsetpgrp set foreground process-group-id

The termios structure stores the values of settable terminal I/O parameters used by functions to control terminal I/O characteristics and the operation of a terminal-device-file. The <termios.h> header file defines the termios structure to contain at least the following members (see termio(7)):

   tcflag_t  c_iflag;      /* input modes */
   tcflag_t  c_oflag;      /* output modes */
   tcflag_t  c_cflag;      /* control modes */
   tcflag_t  c_lflag;      /* local modes */
   cc_t      c_cc[NCCS];   /* control chars */

The <termios.h> header file defines the type tcflag_t as long, the type cc_t as char. The <termios.h> header file also defines the symbolic-constant NCCS as the size of the control-character array.

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UnixWare 7 Release 7.1.4 - 27 April 2004