PROLOG | NAME | SYNOPSIS | DESCRIPTION | RETURN VALUE | ERRORS | EXAMPLES | APPLICATION USAGE | RATIONALE | FUTURE DIRECTIONS | SEE ALSO | COPYRIGHT

TCFLOW(3P)                POSIX Programmer's Manual               TCFLOW(3P)

PROLOG         top

       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         top

       tcflow — suspend or restart the transmission or reception of data

SYNOPSIS         top

       #include <termios.h>

       int tcflow(int fildes, int action);

DESCRIPTION         top

       The tcflow() function shall suspend or restart 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.

        *  If action is TCOOFF, output shall be suspended.

        *  If action is TCOON, suspended output shall be restarted.

        *  If action is TCIOFF and fildes refers to a terminal device, the
           system shall transmit a STOP character, which is intended to
           cause the terminal device to stop transmitting data to the
           system. If fildes is associated with a pseudo-terminal, the STOP
           character need not be transmitted.

        *  If action is TCION and fildes refers to a terminal device, the
           system shall transmit a START character, which is intended to
           cause the terminal device to start transmitting data to the
           system. If fildes is associated with a pseudo-terminal, the START
           character need not be transmitted.

       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, shall cause the process group to be sent a SIGTTOU signal.
       If the calling thread is blocking SIGTTOU signals or the process is
       ignoring SIGTTOU signals, the process shall be allowed to perform the
       operation, and no signal is sent.

RETURN VALUE         top

       Upon successful completion, 0 shall be returned. Otherwise, −1 shall
       be returned and errno set to indicate the error.

ERRORS         top

       The tcflow() function shall fail if:

       EBADF  The fildes argument is not a valid file descriptor.

       EINVAL The action argument is not a supported value.

       EIO    The process group of the writing process is orphaned, the
              calling thread is not blocking SIGTTOU, and the process is not
              ignoring SIGTTOU.

       ENOTTY The file associated with fildes is not a terminal.

       The following sections are informative.

EXAMPLES         top

       None.

APPLICATION USAGE         top

       None.

RATIONALE         top

       None.

FUTURE DIRECTIONS         top

       None.

SEE ALSO         top

       tcsendbreak(3p)

       The Base Definitions volume of POSIX.1‐2008, Chapter 11, General
       Terminal Interface, termios.h(0p)

COPYRIGHT         top

       Portions of this text are reprinted and reproduced in electronic form
       from IEEE Std 1003.1, 2013 Edition, Standard for Information
       Technology -- Portable Operating System Interface (POSIX), The Open
       Group Base Specifications Issue 7, Copyright (C) 2013 by the
       Institute of Electrical and Electronics Engineers, Inc and The Open
       Group.  (This is POSIX.1-2008 with the 2013 Technical Corrigendum 1
       applied.) 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.unix.org/online.html .

       Any typographical or formatting errors that appear in this page are
       most likely to have been introduced during the conversion of the
       source files to man page format. To report such errors, see
       https://www.kernel.org/doc/man-pages/reporting_bugs.html .

IEEE/The Open Group                 2013                          TCFLOW(3P)

Pages that refer to this page: termios.h(0p)