ioctl
OS/161 Reference Manual
Name
ioctl - miscellaneous device I/O operations
Library
Standard C Library (libc, -lc)
Synopsis
#include <sys/ioctl.h>
int
ioctl(int fd, int code, void *data);
Description
ioctl performs an object-specific operation code on the
object referred to by the file handle fd. The data
argument may point to supplemental data required or returned by the
operation. The size of buffer required, if any, and other such matters
are operation-specific.
Traditionally, ioctl is a catchall function for performing operations
that don't fit neatly into any other model.
The ioctl codes are defined in <kern/ioctl.h>, which should be
included via <sys/ioctl.h> by user-level code. As of this
writing, the base OS/161 system defines no ioctls. However, it may
prove useful to implement some, particularly in connection with some
less conventional possible projects.
Return Values
On success, ioctl returns 0. On error, -1 is returned, and
errno is set according to the error
encountered.
Errors
The following error codes should be returned under the conditions
given. Other error codes may be returned for other errors not
mentioned here.
| | |
| EBADF | fd was not a valid file handle. |
| EIOCTL | code was an invalid ioctl for the
object referenced. |
| EFAULT | data was required by the operation
requested, but was an invalid pointer. |