NAME
tcsendbreak — send
a break for a specific duration
SYNOPSIS
#include
<termios.h>
int tcsendbreak(int fildes, int duration);
DESCRIPTION
If the terminal is using asynchronous serial data transmission,
tcsendbreak () shall cause transmission of a
continuous stream of zero-valued bits for a specific duration. If
duration is 0, it shall cause transmission of zero-valued
bits for at least 0.25 seconds, and not more than 0.5 seconds. If
duration is not 0, it shall send zero-valued bits for an
implementation-defined period of time.
The fildes argument is an open file descriptor associated with a terminal.
If the terminal is not using asynchronous serial data
transmission, it is implementation-defined whether
tcsendbreak () sends data to generate a break
condition or returns without taking any action.
Attempts to use tcsendbreak () from a
process which is a member of a background process group on a
fildes associated with its controlling terminal shall
cause the process group to be sent a SIGTTOU signal. If the calling process
is blocking or ignoring SIGTTOU signals, the process shall be allowed to
perform the operation, and no signal is sent.
RETURN VALUE
Upon successful completion, 0 shall be returned. Otherwise, -1 shall be returned and errno set to indicate the error.
ERRORS
The tcsendbreak () function shall fail
if:
- [EBADF]
- The fildes argument is not a valid file descriptor.
- [ENOTTY]
- The file associated with fildes is not a terminal.
The tcsendbreak () function may fail
if:
- [EIO]
- The process group of the writing process is orphaned, and the writing process is not ignoring or blocking SIGTTOU.
EXAMPLES
None.
APPLICATION USAGE
None.
RATIONALE
None.
FUTURE DIRECTIONS
None.
SEE ALSO
XBD V1_chap11(7) , <termios.h>
CHANGE HISTORY
First released in Issue 3. Included for alignment with the POSIX.1-1988 standard.
Issue 6
The following new requirements on POSIX implementations derive from alignment with the Single UNIX Specification:
- In the DESCRIPTION, text previously conditional on _POSIX_JOB_CONTROL is now mandated. This is a FIPS requirement.
- The [EIO] error is added.