TCSENDBREAK(3) OpenBSD Programmer's Manual TCSENDBREAK(3)NAME
tcdrain, tcflow, tcflush, tcsendbreak - line control functions
SYNOPSIS
#include <termios.h>
int
tcdrain(int fd);
int
tcflow(int fd, int action);
int
tcflush(int fd, int action);
int
tcsendbreak(int fd, int len);
DESCRIPTION
The tcdrain() function waits until all output written to the terminal
referenced by fd has been transmitted to the terminal.
The tcflow() function suspends transmission of data to or the reception
of data from the terminal referenced by fd depending on the value of
action. The value of action must be one of the following:
TCOOFF Suspend output.
TCOON Restart suspended output.
TCIOFF Transmit a STOP character, which is intended to cause the
terminal to stop transmitting data to the system. (See the
description of IXOFF in the `Input Modes' section of termios(4)).
TCION Transmit a START character, which is intended to cause the
terminal to start transmitting data to the system. (See the
description of IXOFF in the `Input Modes' section of termios(4)).
The tcflush() function discards any data written to the terminal
referenced by fd which has not been transmitted to the terminal, or any
data received from the terminal but not yet read, depending on the value
of action. The value of action must be one of the following:
TCIFLUSH Flush data received but not read.
TCOFLUSH Flush data written but not transmitted.
TCIOFLUSH Flush both data received but not read and data written but not
transmitted.
The tcsendbreak() function transmits a continuous stream of zero-valued
bits for four-tenths of a second to the terminal referenced by fd. The
len parameter is ignored in this implementation.
RETURN VALUES
Upon successful completion, all of these functions return a value of
zero.
ERRORS
If any error occurs, a value of -1 is returned and the global variable
errno is set to indicate the error, as follows:
[EBADF] The fd argument is not a valid file descriptor.
[EINVAL] The action argument is not a proper value.
[ENOTTY] The file associated with fd is not a terminal.
[EINTR] A signal interrupted the tcdrain() function.
SEE ALSOtcsetattr(3), termios(4)STANDARDS
The tcdrain(), tcflow(), tcflush(), and tcsendbreak() functions are
expected to be compliant with the IEEE Std 1003.1-1988 (``POSIX'')
specification.
OpenBSD 4.9 May 31, 2007 OpenBSD 4.9
