4.4BSD/usr/share/man/cat3/cfsetospeed.0
TCSETATTR(3) BSD Programmer's Manual TCSETATTR(3)
NNAAMMEE
ccffggeettiissppeeeedd, ccffsseettiissppeeeedd, ccffggeettoossppeeeedd, ccffsseettoossppeeeedd, ccffsseettssppeeeedd,
ccffmmaakkeerraaww, ttccggeettaattttrr, ttccsseettaattttrr - manipulating the termios structure
SSYYNNOOPPSSIISS
##iinncclluuddee <<tteerrmmiiooss..hh>>
_s_p_e_e_d___t
ccffggeettiissppeeeedd(_s_t_r_u_c_t _t_e_r_m_i_o_s _*_t);
_i_n_t
ccffsseettiissppeeeedd(_s_t_r_u_c_t _t_e_r_m_i_o_s _*_t, _s_p_e_e_d___t _s_p_e_e_d);
_s_p_e_e_d___t
ccffggeettoossppeeeedd(_s_t_r_u_c_t _t_e_r_m_i_o_s _*_t);
_i_n_t
ccffsseettoossppeeeedd(_s_t_r_u_c_t _t_e_r_m_i_o_s _*_t, _s_p_e_e_d___t _s_p_e_e_d);
_v_o_i_d
ccffsseettssppeeeedd(_s_t_r_u_c_t _t_e_r_m_i_o_s _*_t, _s_p_e_e_d___t _s_p_e_e_d);
_v_o_i_d
ccffmmaakkeerraaww(_s_t_r_u_c_t _t_e_r_m_i_o_s _*_t);
_i_n_t
ttccggeettaattttrr(_i_n_t _f_d, _s_t_r_u_c_t _t_e_r_m_i_o_s _*_t);
_i_n_t
ttccsseettaattttrr(_i_n_t _f_d, _i_n_t _a_c_t_i_o_n, _s_t_r_u_c_t _t_e_r_m_i_o_s _*_t);
DDEESSCCRRIIPPTTIIOONN
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, un-
til 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 speed_t is typdef'd in the include file <_t_e_r_m_i_o_s_._h>. The
value of the integer corresponds directly to the baud rate being repre-
sented, 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 _POSIX_SOURCE
#define EXTA 19200
#define EXTB 38400
#endif /*_POSIX_SOURCE */
The ccffggeettiissppeeeedd function returns the input baud rate in the termios
structure referenced by _t_p.
The ccffsseettiissppeeeedd function sets the input baud rate in the termios struc-
ture referenced by _t_p to _s_p_e_e_d.
The ccffggeettoossppeeeedd function returns the output baud rate in the termios
structure referenced by _t_p.
The ccffsseettoossppeeeedd function sets the output baud rate in the termios struc-
ture referenced by _t_p to _s_p_e_e_d.
The ccffsseettssppeeeedd function sets both the input and output baud rate in the
termios structure referenced by _t_p to _s_p_e_e_d.
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 _e_r_r_n_o 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 _f_d is an open file descriptor, the func-
tions affect the underlying terminal file, not just the open file de-
scription 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 ef-
fect. 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 terminal state.
The ttccggeettaattttrr function copies the parameters associated with the terminal
referenced by _f_d in the termios structure referenced by _t_p. 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 _t_p. The _a_c_t_i_o_n field is created
by _o_r'ing the following values, as specified in the include file
<_t_e_r_m_i_o_s_._h>.
_T_C_S_A_N_O_W The change occurs immediately.
_T_C_S_A_D_R_A_I_N The change occurs after all output written to _f_d has been
transmitted to the terminal. This value of _a_c_t_i_o_n should be
used when changing parameters that affect output.
_T_C_S_A_F_L_U_S_H The change occurs after all output written to _f_d has been
transmitted to the terminal Additionally, any input that has
been received but not read is discarded.
_T_C_S_A_S_O_F_T If this value is _o_r'ed into the _a_c_t_i_o_n value, the values of
the _c___c_f_l_a_g, _c___i_s_p_e_e_d, and _c___o_s_p_e_e_d 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 able to make any of the requested changes, it re-
turns -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 combination 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 _e_r_r_n_o is
set to indicate the error, as follows:
[EBADF] The _f_d argument to ttccggeettaattttrr or ttccsseettaattttrr was not a valid
file descriptor.
[EINTR] The ttccsseettaattttrr function was interrupted by a signal.
[EINVAL] The _a_c_t_i_o_n argument to the ttccsseettaattttrr function was not
valid, or an attempt was made to change an attribute repre-
sented in the termios structure to an unsupported value.
[ENOTTY] The file associated with the _f_d argument to ttccggeettaattttrr or
ttccsseettaattttrr is not a terminal.
SSEEEE AALLSSOO
tcsendbreak(3), termios(4)
SSTTAANNDDAARRDDSS
The ccffggeettiissppeeeedd, ccffsseettiissppeeeedd, ccffggeettoossppeeeedd, ccffsseettoossppeeeedd, ttccggeettaattttrr and
ttccsseettaattttrr functions are expected to be compliant with the IEEE
Std1003.1-1988 (``POSIX'') specification. The ccffmmaakkeerraaww and ccffsseettssppeeeedd
functions, as well as the TCSASOFT option to the ttccsseettaattttrr function are
extensions to the IEEE Std1003.1-1988 (``POSIX'') specification.
4.4BSD June 4, 1993 3