tcflow(3p) — Linux manual page

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.1‐2017, Chapter 11, General
       Terminal Interface, termios.h(0p)

COPYRIGHT         top

       Portions of this text are reprinted and reproduced in electronic
       form from IEEE Std 1003.1-2017, Standard for Information
       Technology -- Portable Operating System Interface (POSIX), The
       Open Group Base Specifications Issue 7, 2018 Edition, Copyright
       (C) 2018 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 .

       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               2017                        TCFLOW(3P)

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