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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

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Linux man-pages 6.15            2025-05-17           TIOCSSOFTCAR(2const)

Pages that refer to this page: ioctl_tty(2)

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