NAME

ioctl − control device

SYNOPSIS

ioctl (fildes, request, arg)

DESCRIPTION

Ioctl performs a variety of functions on character special files (devices).  The writeups of various devices in Section 7 discuss how ioctl applies to them. 

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

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 Section 7.  ­[EINVAL]

RETURN VALUE

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

SEE ALSO

termio(7) in the UNIX Programmer’s Manual.

ASSEMBLER

moveq#54,D0| sys ioctl
movlfildes,A0
movlrequest,D1
movl#argp,A1
trap#0

Version 3.6  —  December 20, 1987