TERMIOS(M)                           UNIX System V



     Name
          termios - POSIX general terminal interface


     Description
          This page discusses the  POSIX  termios  extensions  to  the
          termio(M)  interface.  Only those functions not described in
          termio(M) are described here.

          Certain characters have special functions on  input.   These
          functions  and their default character values are summarized
          as follows:

          SUSP    (ASCII NUL) If the ISIG flag is enabled, receipt  of
                  the  SUSP  character  causes  A SIGTSTP signal to be
                  sent  to  the  current  process  group.   The   SUSP
                  character   is  discarded  when  processed.   It  is
                  normally set to Ctrl-Z.

          Several library functions  apply  to  terminal  files.   The
          primary  calls  use  the following structure, defined in the
          file <termios.h>:

          #define   NCCS 13
          struct termios {
              tcflag_t      c_iflag;     /* input modes */
              tcflag_t      c_oflag;     /* output modes */
              tcflag_t      c_cflag;     /* control modes */
              tcflag_t      c_lflag;     /* local (line discipline) modes */
              char          c_line;      /* line discipline */
              cc_t          c_cc[NCCS];  /* control chars */
              char          c_ispeed;    /* input baud rate */
              char          c_ospeed;    /* output baud rate */
          };

          The additional special control  characters  defined  by  the
          array c_cc.  are:
          10   VSUSP     NUL
          11   VSTART    DC1
          12   VSTOP     DC3

          The following additional line discipline (0)  functions  are
          available in the c_lflag field:

          IEXTEN  0000400  enable extended functions
          TOSTOP  0001000  SIGTTOU on background output

          If  IEXTEN  is  set,  additional  non-POSIX  functions   are
          recognized.  This  is the default. If IEXTEN is not set, the
          modes ICANON, ISIG, IXON, and IXOFF are assumed.

          If TOSTOP is set, the signal SIGTTOU is sent  to the process
          group  of  a  process that tries to write to its controlling
          terminal if it is not  the  foreground  process  group.   By
          default, this signal stops the members of the process group.
          If TOSTOP is not set, the output generated by the process is
          output to the current output stream.

          The associated library functions are found in tcattr(S)  and
          tcflow(S).


     Files
          /dev/tty

          /dev/tty*

          /dev/console


     See Also
          ioctl(S),   signal(S),   stty(C),   tcattr(S),    tcflow(S),
          termio(M), tty(M)


     Standards Conformance
          termios is conformant with:
          IEEE  POSIX  Std  1003.1-1988  with  C  Standard   Language-
          Dependent System Support;
          and The X/Open Portability Guide II of January 1987.


     (printed 2/15/90)                                 TERMIOS(M)