man7.org > Linux > man-pages

Linux/UNIX system programming training

TIOCSSOFTCAR(2const) — Linux manual page

NAME | LIBRARY | SYNOPSIS | DESCRIPTION | RETURN VALUE | SEE ALSO | COLOPHON 

TIOCSSOFTCAR(2const)                                TIOCSSOFTCAR(2const)

NAME         top

       TIOCGSOFTCAR, TIOCSSOFTCAR - marking a line as local

LIBRARY         top

       Standard C library (libc, -lc)

SYNOPSIS         top

       #include <asm/termbits.h>  /* Definition of TIOC*SOFTCAR constants */
       #include <sys/ioctl.h>

       int ioctl(int fd, TIOCGSOFTCAR, int *argp);
       int ioctl(int fd, TIOCSSOFTCAR, const int *argp);

DESCRIPTION         top

       TIOCGSOFTCAR
              ("Get software carrier flag") Get the status of the CLOCAL
              flag in the c_cflag field of the termios structure.

       TIOCSSOFTCAR
              ("Set software carrier flag") Set the CLOCAL flag in the
              termios structure when *argp is nonzero, and clear it
              otherwise.

       If the CLOCAL flag for a line is off, the hardware carrier detect
       (DCD) signal is significant, and an open(2) of the corresponding
       terminal will block until DCD is asserted, unless the O_NONBLOCK
       flag is given.  If CLOCAL is set, the line behaves as if DCD is
       always asserted.  The software carrier flag is usually turned on
       for local devices, and is off for lines with modems.

RETURN VALUE         top

       On success, 0 is returned.  On error, -1 is returned, and errno
       is set to indicate the error.

SEE ALSO         top

       ioctl(2), ioctl_tty(2)

COLOPHON         top

       This page is part of the man-pages (Linux kernel and C library
       user-space interface documentation) project.  Information about
       the project can be found at 
       ⟨https://www.kernel.org/doc/man-pages/⟩.  If you have a bug report
       for this manual page, see
       ⟨https://git.kernel.org/pub/scm/docs/man-pages/man-pages.git/tree/CONTRIBUTING⟩.
       This page was obtained from the tarball man-pages-6.9.1.tar.gz
       fetched from
       ⟨https://mirrors.edge.kernel.org/pub/linux/docs/man-pages/⟩ on
       2024-06-26.  If you discover any rendering problems in this HTML
       version of the page, or you believe there is a better or more up-
       to-date source for the page, or you have corrections or
       improvements to the information in this COLOPHON (which is not
       part of the original manual page), send a mail to
       man-pages@man7.org

Linux man-pages 6.9.1          2024-06-13           TIOCSSOFTCAR(2const)

Pages that refer to this page: ioctl_tty(2)

HTML rendering created 2024-06-26 by Michael Kerrisk, author of The Linux Programming Interface.

For details of in-depth Linux/UNIX system programming training courses that I teach, look here.

Hosting by jambit GmbH.

Cover of TLPI