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tcflush()

Flush the input and/or output stream

Synopsis:

#include <termios.h>

int tcflush( int fildes, 
             int queue_selector );

Arguments:

fildes

A file descriptor that's associated with the data stream that you want to perform the operation on.

queue_selector

The stream or streams that you want to flush. At least the following values for queue_selector are defined in <termios.h>:

• TCIFLUSH -- discard all data that's received, but not yet read, on the device associated with fildes.
• TCOFLUSH -- discard all data that's written, but not yet transmitted, on the device associated with fildes.
• TCIOFLUSH -- discard all data that's written, but not yet transmitted, as well as all data that's received, but not yet read, on the device associated with fildes.

Library:

libc

Use the -l c option to qcc to link against this library. This library is usually included automatically.

Description:

The tcflush() function flushes the input stream, the output stream, or both, depending on the value of the argument queue_selector.

Returns:

0

Success.

-1

An error occurred (errno is set).

Errors:

EBADF

Invalid fildes argument.

EINVAL

Invalid queue_selector argument.

ENOSYS

The resource manager associated with fildes doesn't support this call.

ENOTTY

The argument fildes doesn't refer to a terminal device.

Examples:

#include <termios.h>
#include <fcntl.h>
#include <unistd.h>
#include <stdlib.h>

int main( void )
  {
    int fildes;

    fildes = open( "/dev/ser1", O_RDWR );

    /* Throw away all input data */
    tcflush( fildes, TCIFLUSH );

    close( fildes );
    return EXIT_SUCCESS;
  }

Classification:

POSIX 1003.1

Safety:
Cancellation point	No
Interrupt handler	No
Signal handler	Yes
Thread	Yes

See also:

tcdrain(), tcflow(), tcsendbreak()

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