TCFLOW(3C) Standard C Library Functions TCFLOW(3C)
tcflow - suspend or restart the transmission or reception of data
#include <termios.h>
int tcflow(int fildes, int action);
The tcflow() function suspends transmission or reception of data on
the object referred to by fildes, depending on the value of action.
The fildes argument is an open file descriptor associated with a
terminal.
o If action is TCOOFF, output is suspended.
o If action is TCOON, suspended output is restarted.
o If action is TCIOFF, the system transmits a STOP
character, which is intended to cause the terminal device
to stop transmitting data to the system.
o If action is TCION, the system transmits a START
character, which is intended to cause the terminal device
to start transmitting data to the system.
The default on the opening of a terminal file is that neither its
input nor its output are suspended.
Attempts to use tcflow() from a process which is a member of a
background process group on a fildes associated with its controlling
terminal, will cause the process group to be sent a SIGTTOU signal.
If the calling process is blocking or ignoring SIGTTOU signals, the
process is allowed to perform the operation, and no signal is sent.
Upon successful completion, 0 is returned. Otherwise, -1 is returned
and errno is set to indicate the error.
The tcflow() function will fail if:
EBADF
The fildes argument is not a valid file descriptor.
EINVAL
The action argument is not a supported value.
ENOTTY
The file associated with fildes is not a terminal.
The tcflow() function may fail if:
EIO
The process group of the writing process is orphaned, and the
writing process is not ignoring or blocking SIGTTOU.
See attributes(7) for descriptions of the following attributes:
+--------------------+--------------------------------+
| ATTRIBUTE TYPE | ATTRIBUTE VALUE |
+--------------------+--------------------------------+
|Interface Stability | Standard |
+--------------------+--------------------------------+
|MT-Level | MT-Safe, and Async-Signal-Safe |
+--------------------+--------------------------------+
tcsendbreak(3C), termio(4I), attributes(7), standards(7)
August 14, 2002 TCFLOW(3C)
NAME
tcflow - suspend or restart the transmission or reception of data
SYNOPSIS
#include <termios.h>
int tcflow(int fildes, int action);
DESCRIPTION
The tcflow() function suspends transmission or reception of data on
the object referred to by fildes, depending on the value of action.
The fildes argument is an open file descriptor associated with a
terminal.
o If action is TCOOFF, output is suspended.
o If action is TCOON, suspended output is restarted.
o If action is TCIOFF, the system transmits a STOP
character, which is intended to cause the terminal device
to stop transmitting data to the system.
o If action is TCION, the system transmits a START
character, which is intended to cause the terminal device
to start transmitting data to the system.
The default on the opening of a terminal file is that neither its
input nor its output are suspended.
Attempts to use tcflow() from a process which is a member of a
background process group on a fildes associated with its controlling
terminal, will cause the process group to be sent a SIGTTOU signal.
If the calling process is blocking or ignoring SIGTTOU signals, the
process is allowed to perform the operation, and no signal is sent.
RETURN VALUES
Upon successful completion, 0 is returned. Otherwise, -1 is returned
and errno is set to indicate the error.
ERRORS
The tcflow() function will fail if:
EBADF
The fildes argument is not a valid file descriptor.
EINVAL
The action argument is not a supported value.
ENOTTY
The file associated with fildes is not a terminal.
The tcflow() function may fail if:
EIO
The process group of the writing process is orphaned, and the
writing process is not ignoring or blocking SIGTTOU.
ATTRIBUTES
See attributes(7) for descriptions of the following attributes:
+--------------------+--------------------------------+
| ATTRIBUTE TYPE | ATTRIBUTE VALUE |
+--------------------+--------------------------------+
|Interface Stability | Standard |
+--------------------+--------------------------------+
|MT-Level | MT-Safe, and Async-Signal-Safe |
+--------------------+--------------------------------+
SEE ALSO
tcsendbreak(3C), termio(4I), attributes(7), standards(7)
August 14, 2002 TCFLOW(3C)