IOCTL(S)                 XENIX System V                  IOCTL(S)



     Name
          ioctl - Controls character devices.

     Syntax
          #include <sys/ioctl.h>

          int ioctl(fildes, request, arg)
          int fildes;

     Description
          ioctl performs a variety of functions on character special
          files (devices).  The arguments request and arg depend on
          which device ioctl is being applied to.  The writeups of
          various devices in Section M discuss how ioctl applies to
          them.

          ioctl fails if one or more of the following are true:

               A signal is caught during ioctl system call.  [EINTR]

               fildes is not a valid open file descriptor.  [EBADF]

               fildes is not associated with a character special
               device.  [ENOTTY]

               request or arg is not valid.  See termio(M).  [EINVAL]

               A signal was caught during the ioctl system call.
               [EINTR]

     Return Value
          If an error has occurred, a value of -1 is returned and
          errno is set to indicate the error.

     See Also
          tty(M), termio(M)



















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