TCSENDBREAK(3-POSIX)RISC/os Reference Manual TCSENDBREAK(3-POSIX)
NAME
tcsendbreak, tcdrain, tcflush, tcflow - line control func-
tions
SYNOPSIS
#include <termios.h>
int tcsendbreak(fildes, duration)
int fildes;
int duration;
int tcdrain(fildes)
int fildes;
int tcflush(fildes, queueselector)
int fildes;
int queueselector;
int tcflow(fildes, action)
int fildes;
int action;
DESCRIPTION
If the terminal is using asynchronous serial data transmis-
sion, tcsendbreak causes transmission of a continuous stream
of zero-valued bits for a specific duration. If duration is
zero, the transmission will be for at least 0.25 seconds and
not more than 0.5 seconds. If duration is not zero, no data
is transmitted.
If the terminal is not using asynchronous serial data
transmission, tcsendbreak returns without taking any action.
tcdrain waits until all output written to fildes has been
transmitted.
tcflush discards data written to fildes but not transmitted,
or data received but not read, depending on queue_selector:
1. If queue_selector is TCIFLUSH, data received but not
read is flushed.
2. If queue_selector is TCOFLUSH, date written but not
transmitted is flushed.
3. If queue_selector is TCIOFLUSH, data received but
not read and data written but not transmitted are
flushed.
tcflow suspends transmission or reception of data on fildes,
depending on action:
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TCSENDBREAK(3-POSIX)RISC/os Reference Manual TCSENDBREAK(3-POSIX)
1. If action is TCOOFF, output is suspended.
2. If action is TCOON, suspended output is restarted.
3. If action is TCIOFF, a STOP character is transmitted
by the system to indicate to the device that it
should stop transmitting data to the system.
4. If action is TCION, a START character is transmitted
by the system to indicate to the device that it
should start sending data to the system.
When a terminal file is opened, neither its input nor its
output is suspended.
RETURN VALUES
Upon successful completion, 0 is returned. Otherwise, -1 is
returned and errno is set to indicate the error.
ERRORS
If any of the following conditions occur, tcsendbreak
returns -1 and sets errno to indicate the error:
[EBADF] fildes is not a valid file descriptor.
[ENOTTY] The file associated with fildes is not a
terminal.
If any of the following conditions occur, tcdrain returns -1
and sets errno to indicate the error:
[EBADF] fildes is not a valid file descriptor.
[EINTR] A signal interrupted tcdrain.
[ENOTTY] The file associated with fildes is not a
terminal.
If any of the following conditions occur, tcflush returns -1
and sets errno to indicate the error:
[EBADF] fildes is not a valid file descriptor.
[EINVAL] queue_selector is not valid.
[ENOTTY] The file associated with fildes is not a
terminal.
If any of the following conditions occur, tcflow returns -1
and sets errno to indicate the error:
[EBADF] fildes is not a valid file descriptor.
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TCSENDBREAK(3-POSIX)RISC/os Reference Manual TCSENDBREAK(3-POSIX)
[EINVAL] action is not valid.
[ENOTTY] The file associated with fildes is not a
terminal.
SEE ALSO
termios(7).
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