version 4, including all changes.
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IOCTL |
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!!!IOCTL |
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NAME |
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SYNOPSIS |
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DESCRIPTION |
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RETURN VALUE |
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ERRORS |
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CONFORMING TO |
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SEE ALSO |
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---- |
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!!NAME |
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ioctl - control device |
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!!SYNOPSIS |
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#include <sys/ioctl.h> |
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__int ioctl(int__ ''d''__, int__ ''request''__,...)__ |
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[[The "third" argument is __char *__''argp'', and will be so named for this |
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discussion.] |
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!!DESCRIPTION |
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The __ioctl__ function manipulates the underlying device |
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parameters of special files. In particular, many operating |
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characteristics of character special files (e.g. terminals) |
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may be controlled with __ioctl__ requests. The argument |
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''d'' must be an open file descriptor. |
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An ioctl ''request'' has encoded in it whether the |
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argument is an ''in'' parameter or ''out'' parameter, |
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and the size of the argument ''argp'' in bytes. Macros |
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and defines used in specifying an ioctl ''request'' are |
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located in the file ''''. |
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!!RETURN VALUE |
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Usually, on success zero is returned. A few ioctls use the |
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return value as an output parameter and return a nonnegative |
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value on success. On error, -1 is returned, and ''errno'' |
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is set appropriately. |
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!!ERRORS |
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;__EBADF__: ''d'' is not a valid descriptor. |
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;__EFAULT__: ''argp'' references an inaccessible memory area. |
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;__ENOTTY__: ''d'' is not associated with a character special device. |
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;__ENOTTY__: The specified request does not apply to the kind of object that the descriptor ''d'' references. |
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;__EINVAL__: ''Request'' or ''argp'' is not valid. This normally happens if you've provided the wrong type of request for the file descriptor you passed to the ioctl |
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!!CONFORMING TO |
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No single standard. Arguments, returns, and semantics of ioctl(2) vary according to the device driver in question (the call is used as a catch-all for operations that don't cleanly fit the Unix stream I/O model). See |
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!PerryLorier |
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ioctl_list(2) for a list of many of the known __ioctl__ calls. The __ioctl__ function call appeared in Version 7 AT&T Unix. |
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PerryLorier |
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!!SEE ALSO |
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execve(2), fcntl(2), ioctl_list(2), mt(4), sd(4), tty(4), netdevice(7), socket(7) |
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---- |
