PROLOG¶

This manual page is part of the POSIX Programmer's Manual. The Linux implementation of this interface may differ (consult the corresponding Linux manual page for details of Linux behavior), or the interface may not be implemented on Linux.

NAME¶

tcdrain - wait for transmission of output

SYNOPSIS¶

#include <termios.h>

int tcdrain(int fildes);

DESCRIPTION¶

The tcdrain() function shall block until all output written to the object referred to by fildes is transmitted. The fildes argument is an open file descriptor associated with a terminal.

Any attempts to use tcdrain() 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 tcdrain() function shall fail if:

EBADF

The fildes argument is not a valid file descriptor.

EINTR

A signal interrupted tcdrain().

ENOTTY

The file associated with fildes is not a terminal.

The tcdrain() function may fail if:

EIO

The process group of the writing process is orphaned, and the writing process is not ignoring or blocking SIGTTOU.

The following sections are informative.

EXAMPLES¶

None.

APPLICATION USAGE¶

None.

RATIONALE¶

None.

FUTURE DIRECTIONS¶

None.

SEE ALSO¶

tcflush(), the Base Definitions volume of IEEE Std 1003.1-2001, Chapter 11, General Terminal Interface, <termios.h>, <unistd.h>

COPYRIGHT¶

Portions of this text are reprinted and reproduced in electronic form from IEEE Std 1003.1, 2003 Edition, Standard for Information Technology -- Portable Operating System Interface (POSIX), The Open Group Base Specifications Issue 6, Copyright (C) 2001-2003 by the Institute of Electrical and Electronics Engineers, Inc and The Open Group. In the event of any discrepancy between this version and the original IEEE and The Open Group Standard, the original IEEE and The Open Group Standard is the referee document. The original Standard can be obtained online at http://www.opengroup.org/unix/online.html .