IOCTL

Section: System Calls (2)
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NAME

ioctl, stty, gtty - control device  

SYNOPSIS

#include <sgtty.h>

ioctl(fildes, request, argp)
struct sgttyb *argp;

stty(fildes, argp)
struct sgttyb *argp;

gtty(fildes, argp)
struct sgttyb *argp;  

DESCRIPTION

Ioctl performs a variety of functions on character special files (devices). The writeups of various devices in section 4 discuss how ioctl applies to them.

For certain status setting and status inquiries about terminal devices, the functions stty and gtty are equivalent to

ioctl(fildes, TIOCSETP, argp)
ioctl(fildes, TIOCGETP, argp)

respectively; see tty(4).

The following two calls, however, apply to any open file:

ioctl(fildes, FIOCLEX, NULL);
ioctl(fildes, FIONCLEX, NULL);

The first causes the file to be closed automatically during a successful exec operation; the second reverses the effect of the first.  

SEE ALSO

stty(1), tty(4), exec(2)  

DIAGNOSTICS

Zero is returned if the call was successful; -1 if the file descriptor does not refer to the kind of file for which it was intended.  

BUGS

Strictly speaking, since ioctl may be extended in different ways to devices with different properties, argp should have an open-ended declaration like
union { struct sgttyb ...; ... } *argp;

The important thing is that the size is fixed by `struct sgttyb'.  

ASSEMBLER

(ioctl = 54.)
sys ioctl; fildes; request; argp

(stty = 31.)
(file descriptor in r0)
stty; argp

(gtty = 32.)
(file descriptor in r0)
sys gtty; argp


 

Index

NAME
SYNOPSIS
DESCRIPTION
SEE ALSO
DIAGNOSTICS
BUGS
ASSEMBLER

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Time: 10:17:28 GMT, December 28, 2024