Open System Services Library Calls Reference Manual (G06.28+, H06.05+)

OSS Library Calls (t - v) tcsendbreak(3)
NAME
tcsendbreak - Sends a break on an asynchronous serial data line
LIBRARY
G-series native OSS processes: system library
H-series OSS processes: implicit libraries
SYNOPSIS
#include <termios.h>
int tcsendbreak(
int filedes,
int duration);
PARAMETERS
filedes Specifies an open file descriptor.
duration Specifies the number of milliseconds for which zero-valued bits are transmitted.
If the value of the duration parameter is 0 (zero), transmission of zero-valued
bits occurs for 250 milliseconds. If duration is not 0, transmission of zero-
valued bits is for duration milliseconds.
The value used should be at least 250 milliseconds and not more than 500 mil-
liseconds.
DESCRIPTION
If the terminal is using asynchronous serial data transmission, the tcsendbreak( ) function causes
transmission of a continuous stream of zero-valued bits for a specific duration. If the terminal is
not using asynchronous serial data transmission, the tcsendbreak() function sends break data to
generate a break condition or returns without taking any action.
Attempts to use the tcsendbreak() function from a process that is a member of a background
process group on a filedes associated with its controlling terminal causes the process group to be
sent a SIGTTOU signal. If the calling process is blocking or ignoring the SIGTTOU signal, the
process is allowed to perform the operation and no signal is sent.
RETURN VALUES
Upon successful completion, the value 0 (zero) is returned. Otherwise, the value -1 is returned
and errno is set to indicate the error.
ERRORS
If any of the following conditions occurs, the tcsendbreak() function sets errno to the
corresponding value:
[EBADF] The filedes parameter does not specify a valid open file descriptor.
[EISGUARDIAN]
The value used for the filedes parameter is appropriate only in the Guardian
environment.
[ENETDOWN]
The filedes parameter specifies a file in /E (a remote $ZTNT process) but com-
munication with the remote node has been lost.
[ENOTTY] The file associated with the filedes parameter is not a terminal.
[EWRONGID] The function was called for an operation involving an operating system
input/output process (IOP) that is in a down state or has failed.
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