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TCSENDBREAK(3)        DragonFly Library Functions Manual        TCSENDBREAK(3)

NAME

tcsendbreak, tcdrain, tcflush, tcflow -- line control functions

LIBRARY

Standard C Library (libc, -lc)

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 ALSO

tcsetattr(3), termios(4)

STANDARDS

The tcsendbreak(), tcdrain(), tcflush() and tcflow() functions are expected to be compliant with the IEEE Std 1003.1-1988 (``POSIX.1'') specification. DragonFly 4.3 June 4, 1993 DragonFly 4.3

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