ioctl(2) [opendarwin man page]

IOCTL(2)						      BSD System Calls Manual							  IOCTL(2)

NAME

     ioctl -- control device

SYNOPSIS

     #include <sys/ioctl.h>

     int
     ioctl(int d, unsigned long request, char *argp);

DESCRIPTION

     The ioctl() function manipulates the underlying device parameters of special files.  In particular, many operating characteristics of charac-
     ter special files (e.g. terminals) may be controlled with ioctl() requests.  The argument d must be an open file descriptor.

     An  ioctl request has encoded in it whether the argument is an ``in'' parameter or ``out'' parameter, and the size of the argument argp in
     bytes.  Macros and defines used in specifying an ioctl request are located in the file <sys/ioctl.h>.

RETURN VALUES

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

ERRORS

     Ioctl() will fail if:

     [EBADF]		d is not a valid descriptor.

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

     [ENOTTY]		The specified request does not apply to the kind of object that the descriptor d references.

     [EINVAL]		Request or argp is not valid.

SEE ALSO

     mt(1), cdio(1), chio(1), execve(2), fcntl(2), tty(4), intro(4)

HISTORY

     An ioctl() function call appeared in Version 7 AT&T UNIX.

4th Berkeley Distribution					 December 11, 1993					 4th Berkeley Distribution

IOCTL(2)							System Calls Manual							  IOCTL(2)

NAME

       ioctl - control device

SYNOPSIS

       #include <sys/ioctl.h>

       ioctl(d, request, argp)
       int d;
       unsigned long request;
       char *argp;

DESCRIPTION

       Ioctl  performs a variety of functions on open descriptors.  In particular, many operating characteristics of character special files (e.g.
       terminals) may be controlled with ioctl requests.  The writeups of various devices in section 4 discuss how ioctl applies to them.

       An  ioctl request has encoded in it whether the argument is an "in" parameter or "out" parameter, and the size  of  the	argument  argp	in
       bytes.  Macros and defines used in specifying an ioctl request are located in the file <sys/ioctl.h>.

RETURN VALUE

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

ERRORS

       Ioctl will fail if one or more of the following are true:

       [EBADF]	      D is not a valid descriptor.

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

       [ENOTTY]       The specified request does not apply to the kind of object that the descriptor d references.

       [EINVAL]       Request or argp is not valid.

SEE ALSO

       execve(2), fcntl(2), mt(4), tty(4), intro(4N)

4th Berkeley Distribution					   March 4, 1986							  IOCTL(2)