TCSETATTR(3) BSD Library Functions Manual TCSETATTR(3)

NAME
     ccffggeettiissppeeeedd, ccffsseettiissppeeeedd, ccffggeettoossppeeeedd, ccffsseettoossppeeeedd, ccffsseettssppeeeedd,
     ccffmmaakkeerraaww, ttccggeettaattttrr, ttccsseettaattttrr - manipulating the termios structure

LLIIBBRRAARRYY
     Standard C Library (libc, -lc)

SYNOPSIS
     ##iinncclluuddee <>

     speedt
     ccffggeettiissppeeeedd(const struct termios *t);

     int
     ccffsseettiissppeeeedd(struct termios *t, speedt speed);

     speedt
     ccffggeettoossppeeeedd(const struct termios *t);

     int
     ccffsseettoossppeeeedd(struct termios *t, speedt speed);

     int
     ccffsseettssppeeeedd(struct termios *t, speedt speed);

     void
     ccffmmaakkeerraaww(struct termios *t);

     int
     ttccggeettaattttrr(int fd, struct termios *t);

     int
     ttccsseettaattttrr(int fd, int action, const struct termios *t);

DESCRIPTION
     The ccffmmaakkeerraaww(), ttccggeettaattttrr() and ttccsseettaattttrr() functions are provided for
     getting and setting the termios structure.

     The ccffggeettiissppeeeedd(), ccffsseettiissppeeeedd(), ccffggeettoossppeeeedd(), ccffsseettoossppeeeedd() and
     ccffsseettssppeeeedd() functions are provided for getting and setting the baud rate
     values in the termios structure.  The effects of the functions on the
     terminal as described below do not become effective, nor are all errors
     detected, until the ttccsseettaattttrr() function is called.  Certain values for
     baud rates set in the termios structure and passed to ttccsseettaattttrr() have
     special meanings.  These are discussed in the portion of the manual page
     that describes the ttccsseettaattttrr() function.

GGEETTTTIINNGG AANNDD SSEETTTTIINNGG TTHHEE BBAAUUDD RRAATTEE
     The input and output baud rates are found in the termios structure.  The
     unsigned integer speedt is typdef'd in the include file .
     The value of the integer corresponds directly to the baud rate being rep-
     resented, however, the following symbolic values are defined.

     #define B0      0
     #define B50     50
     #define B75     75
     #define B110    110
     #define B134    134
     #define B150    150
     #define B200    200
     #define B300    300
     #define B600    600
     #define B1200   1200
     #define B1800   1800
     #define B2400   2400
     #define B4800   4800
     #define B9600   9600
     #define B19200  19200
     #define B38400  38400
     #ifndef POSIXCSOURCE
     #define EXTA    19200
     #define EXTB    38400
     #endif  /*POSIXCSOURCE */

     The ccffggeettiissppeeeedd() function returns the input baud rate in the termios
     structure referenced by tp.

     The ccffsseettiissppeeeedd() function sets the input baud rate in the termios struc-
     ture referenced by tp to speed.

     The ccffggeettoossppeeeedd() function returns the output baud rate in the termios
     structure referenced by tp.

     The ccffsseettoossppeeeedd() function sets the output baud rate in the termios
     structure referenced by tp to speed.

     The ccffsseettssppeeeedd() function sets both the input and output baud rate in the
     termios structure referenced by tp to speed.

     Upon successful completion, the functions ccffsseettiissppeeeedd(), ccffsseettoossppeeeedd(),
     and ccffsseettssppeeeedd() return a value of 0.  Otherwise, a value of -1 is
     returned and the global variable errno is set to indicate the error.

GGEETTTTIINNGG AANNDD SSEETTTTIINNGG TTHHEE TTEERRMMIIOOSS SSTTAATTEE
     This section describes the functions that are used to control the general
     terminal interface.  Unless otherwise noted for a specific command, these
     functions are restricted from use by background processes.  Attempts to
     perform these operations shall cause the process group to be sent a SIGT-
     TOU signal.  If the calling process is blocking or ignoring SIGTTOU sig-
     nals, the process is allowed to perform the operation and the SIGTTOU
     signal is not sent.

     In all the functions, although fd is an open file descriptor, the func-
     tions affect the underlying terminal file, not just the open file
     description associated with the particular file descriptor.

     The ccffmmaakkeerraaww() function sets the flags stored in the termios structure
     to a state disabling all input and output processing, giving a ``raw I/O
     path''.  It should be noted that there is no function to reverse this
     effect.  This is because there are a variety of processing options that
     could be re-enabled and the correct method is for an application to snap-
     shot the current terminal state using the function ttccggeettaattttrr(), setting
     raw mode with ccffmmaakkeerraaww() and the subsequent ttccsseettaattttrr(), and then using
     another ttccsseettaattttrr() with the saved state to revert to the previous termi-
     nal state.

     The ttccggeettaattttrr() function copies the parameters associated with the termi-
     nal referenced by fd in the termios structure referenced by tp.  This
     function is allowed from a background process, however, the terminal
     attributes may be subsequently changed by a foreground process.

     The ttccsseettaattttrr() function sets the parameters associated with the terminal
     from the termios structure referenced by tp.  The action field is created
     by or'ing the following values, as specified in the include file
     .

     TCSANOW    The change occurs immediately.

     TCSADRAIN  The change occurs after all output written to fd has been
                transmitted to the terminal.  This value of action should be
                used when changing parameters that affect output.

     TCSAFLUSH  The change occurs after all output written to fd has been
                transmitted to the terminal.  Additionally, any input that has
                been received but not read is discarded.

     TCSASOFT   If this value is or'ed into the action value, the values of
                the ccflag, cispeed, and cospeed fields are ignored.

     The 0 baud rate is used to terminate the connection.  If 0 is specified
     as the output speed to the function ttccsseettaattttrr(), modem control will no
     longer be asserted on the terminal, disconnecting the terminal.

     If zero is specified as the input speed to the function ttccsseettaattttrr(), the
     input baud rate will be set to the same value as that specified by the
     output baud rate.

     If ttccsseettaattttrr() is unable to make any of the requested changes, it returns
     -1 and sets errno.  Otherwise, it makes all of the requested changes it
     can.  If the specified input and output baud rates differ and are a com-
     bination that is not supported, neither baud rate is changed.

     Upon successful completion, the functions ttccggeettaattttrr() and ttccsseettaattttrr()
     return a value of 0.  Otherwise, they return -1 and the global variable
     errno is set to indicate the error, as follows:

     [EBADF]            The fd argument to ttccggeettaattttrr() or ttccsseettaattttrr() was not
                        a valid file descriptor.

     [EINTR]            The ttccsseettaattttrr() function was interrupted by a signal.

     [EINVAL]           The action argument to the ttccsseettaattttrr() function was
                        not valid, or an attempt was made to change an
                        attribute represented in the termios structure to an
                        unsupported value.

     [ENOTTY]           The file associated with the fd argument to
                        ttccggeettaattttrr() or ttccsseettaattttrr() is not a terminal.

SEE ALSO
     tcsendbreak(3), termios(4)

STANDARDS     The ccffggeettiissppeeeedd(), ccffsseettiissppeeeedd(), ccffggeettoossppeeeedd(), ccffsseettoossppeeeedd(),
     ttccggeettaattttrr() and ttccsseettaattttrr() functions are expected to be compliant with
     the IEEE Std 1003.1-1988 (``POSIX.1'') specification.  The ccffmmaakkeerraaww()
     and ccffsseettssppeeeedd() functions, as well as the TCSASOFT option to the
     ttccsseettaattttrr() function are extensions to the IEEE Std 1003.1-1988
     (``POSIX.1'') specification.

BSD                             January 2, 1994                            BSD