IOCTL(3P) POSIX Programmer's Manual IOCTL(3P)
PROLOG
This manual page is part of the POSIX Programmer's Manual. The Linux
implementation of this interface may differ (consult the corresponding
Linux manual page for details of Linux behavior), or the interface may
not be implemented on Linux.
NAME
ioctl -- control a STREAMS device (STREAMS)
SYNOPSIS
#include <stropts.h>
int ioctl(int fildes, int request, ... /* arg */);
DESCRIPTION
The ioctl() function shall perform a variety of control functions on
STREAMS devices. For non-STREAMS devices, the functions performed by
this call are unspecified. The request argument and an optional third
argument (with varying type) shall be passed to and interpreted by the
appropriate part of the STREAM associated with fildes.
The fildes argument is an open file descriptor that refers to a device.
The request argument selects the control function to be performed and
shall depend on the STREAMS device being addressed.
The arg argument represents additional information that is needed by
this specific STREAMS device to perform the requested function. The
type of arg depends upon the particular control request, but it shall
be either an integer or a pointer to a device-specific data structure.
The ioctl() commands applicable to STREAMS, their arguments, and error
conditions that apply to each individual command are described below.
The following ioctl() commands, with error values indicated, are appli-
cable to all STREAMS files:
I_PUSH Pushes the module whose name is pointed to by arg onto the
top of the current STREAM, just below the STREAM head. It
then calls the open() function of the newly-pushed module.
The ioctl() function with the I_PUSH command shall fail if:
EINVAL Invalid module name.
ENXIO Open function of new module failed.
ENXIO Hangup received on fildes.
I_POP Removes the module just below the STREAM head of the STREAM
pointed to by fildes. The arg argument should be 0 in an
I_POP request.
The ioctl() function with the I_POP command shall fail if:
EINVAL No module present in the STREAM.
ENXIO Hangup received on fildes.
I_LOOK Retrieves the name of the module just below the STREAM head
of the STREAM pointed to by fildes, and places it in a
character string pointed to by arg. The buffer pointed to
by arg should be at least FMNAMESZ+1 bytes long, where
FMNAMESZ is defined in <stropts.h>.
The ioctl() function with the I_LOOK command shall fail if:
EINVAL No module present in the STREAM.
I_FLUSH Flushes read and/or write queues, depending on the value of
arg. Valid arg values are:
FLUSHR Flush all read queues.
FLUSHW Flush all write queues.
FLUSHRW Flush all read and all write queues.
The ioctl() function with the I_FLUSH command shall fail
if:
EINVAL Invalid arg value.
EAGAIN or ENOSR
Unable to allocate buffers for flush message.
ENXIO Hangup received on fildes.
I_FLUSHBAND Flushes a particular band of messages. The arg argument
points to a bandinfo structure. The bi_flag member may be
one of FLUSHR, FLUSHW, or FLUSHRW as described above. The
bi_pri member determines the priority band to be flushed.
I_SETSIG Requests that the STREAMS implementation send the SIGPOLL
signal to the calling process when a particular event has
occurred on the STREAM associated with fildes. I_SETSIG
supports an asynchronous processing capability in STREAMS.
The value of arg is a bitmask that specifies the events for
which the process should be signaled. It is the bitwise-
inclusive OR of any combination of the following constants:
S_RDNORM A normal (priority band set to 0) message has
arrived at the head of a STREAM head read
queue. A signal shall be generated even if the
message is of zero length.
S_RDBAND A message with a non-zero priority band has
arrived at the head of a STREAM head read
queue. A signal shall be generated even if the
message is of zero length.
S_INPUT A message, other than a high-priority message,
has arrived at the head of a STREAM head read
queue. A signal shall be generated even if the
message is of zero length.
S_HIPRI A high-priority message is present on a STREAM
head read queue. A signal shall be generated
even if the message is of zero length.
S_OUTPUT The write queue for normal data (priority band
0) just below the STREAM head is no longer
full. This notifies the process that there is
room on the queue for sending (or writing) nor-
mal data downstream.
S_WRNORM Equivalent to S_OUTPUT.
S_WRBAND The write queue for a non-zero priority band
just below the STREAM head is no longer full.
This notifies the process that there is room on
the queue for sending (or writing) priority
data downstream.
S_MSG A STREAMS signal message that contains the SIG-
POLL signal has reached the front of the STREAM
head read queue.
S_ERROR Notification of an error condition has reached
the STREAM head.
S_HANGUP Notification of a hangup has reached the STREAM
head.
S_BANDURG When used in conjunction with S_RDBAND, SIGURG
is generated instead of SIGPOLL when a priority
message reaches the front of the STREAM head
read queue.
If arg is 0, the calling process shall be unregistered and
shall not receive further SIGPOLL signals for the stream
associated with fildes.
Processes that wish to receive SIGPOLL signals shall ensure
that they explicitly register to receive them using I_SET-
SIG. If several processes register to receive this signal
for the same event on the same STREAM, each process shall
be signaled when the event occurs.
The ioctl() function with the I_SETSIG command shall fail
if:
EINVAL The value of arg is invalid.
EINVAL The value of arg is 0 and the calling process is not
registered to receive the SIGPOLL signal.
EAGAIN There were insufficient resources to store the sig-
nal request.
I_GETSIG Returns the events for which the calling process is cur-
rently registered to be sent a SIGPOLL signal. The events
are returned as a bitmask in an int pointed to by arg,
where the events are those specified in the description of
I_SETSIG above.
The ioctl() function with the I_GETSIG command shall fail
if:
EINVAL Process is not registered to receive the SIGPOLL
signal.
I_FIND Compares the names of all modules currently present in the
STREAM to the name pointed to by arg, and returns 1 if the
named module is present in the STREAM, or returns 0 if the
named module is not present.
The ioctl() function with the I_FIND command shall fail if:
EINVAL arg does not contain a valid module name.
I_PEEK Retrieves the information in the first message on the
STREAM head read queue without taking the message off the
queue. It is analogous to getmsg() except that this command
does not remove the message from the queue. The arg argu-
ment points to a strpeek structure.
The application shall ensure that the maxlen member in the
ctlbuf and databuf strbuf structures is set to the number
of bytes of control information and/or data information,
respectively, to retrieve. The flags member may be marked
RS_HIPRI or 0, as described by getmsg(). If the process
sets flags to RS_HIPRI, for example, I_PEEK shall only look
for a high-priority message on the STREAM head read queue.
I_PEEK returns 1 if a message was retrieved, and returns 0
if no message was found on the STREAM head read queue, or
if the RS_HIPRI flag was set in flags and a high-priority
message was not present on the STREAM head read queue. It
does not wait for a message to arrive. On return, ctlbuf
specifies information in the control buffer, databuf speci-
fies information in the data buffer, and flags contains the
value RS_HIPRI or 0.
I_SRDOPT Sets the read mode using the value of the argument arg.
Read modes are described in read(). Valid arg flags are:
RNORM Byte-stream mode, the default.
RMSGD Message-discard mode.
RMSGN Message-nondiscard mode.
The bitwise-inclusive OR of RMSGD and RMSGN shall return
[EINVAL]. The bitwise-inclusive OR of RNORM and either
RMSGD or RMSGN shall result in the other flag overriding
RNORM which is the default.
In addition, treatment of control messages by the STREAM
head may be changed by setting any of the following flags
in arg:
RPROTNORM Fail read() with [EBADMSG] if a message con-
taining a control part is at the front of the
STREAM head read queue.
RPROTDAT Deliver the control part of a message as data
when a process issues a read().
RPROTDIS Discard the control part of a message, deliver-
ing any data portion, when a process issues a
read().
The ioctl() function with the I_SRDOPT command shall fail
if:
EINVAL The arg argument is not valid.
I_GRDOPT Returns the current read mode setting, as described above,
in an int pointed to by the argument arg. Read modes are
described in read().
I_NREAD Counts the number of data bytes in the data part of the
first message on the STREAM head read queue and places this
value in the int pointed to by arg. The return value for
the command shall be the number of messages on the STREAM
head read queue. For example, if 0 is returned in arg, but
the ioctl() return value is greater than 0, this indicates
that a zero-length message is next on the queue.
I_FDINSERT Creates a message from specified buffer(s), adds informa-
tion about another STREAM, and sends the message down-
stream. The message contains a control part and an optional
data part. The data and control parts to be sent are dis-
tinguished by placement in separate buffers, as described
below. The arg argument points to a strfdinsert structure.
The application shall ensure that the len member in the
ctlbuf strbuf structure is set to the size of a t_uscalar_t
plus the number of bytes of control information to be sent
with the message. The fildes member specifies the file
descriptor of the other STREAM, and the offset member,
which must be suitably aligned for use as a t_uscalar_t,
specifies the offset from the start of the control buffer
where I_FDINSERT shall store a t_uscalar_t whose interpre-
tation is specific to the STREAM end. The application shall
ensure that the len member in the databuf strbuf structure
is set to the number of bytes of data information to be
sent with the message, or to 0 if no data part is to be
sent.
The flags member specifies the type of message to be cre-
ated. A normal message is created if flags is set to 0, and
a high-priority message is created if flags is set to
RS_HIPRI. For non-priority messages, I_FDINSERT shall block
if the STREAM write queue is full due to internal flow con-
trol conditions. For priority messages, I_FDINSERT does
not block on this condition. For non-priority messages,
I_FDINSERT does not block when the write queue is full and
O_NONBLOCK is set. Instead, it fails and sets errno to
[EAGAIN].
I_FDINSERT also blocks, unless prevented by lack of inter-
nal resources, waiting for the availability of message
blocks in the STREAM, regardless of priority or whether
O_NONBLOCK has been specified. No partial message is sent.
The ioctl() function with the I_FDINSERT command shall fail
if:
EAGAIN A non-priority message is specified, the O_NONBLOCK
flag is set, and the STREAM write queue is full due
to internal flow control conditions.
EAGAIN or ENOSR
Buffers cannot be allocated for the message that is
to be created.
EINVAL One of the following:
-- The fildes member of the strfdinsert struc-
ture is not a valid, open STREAM file
descriptor.
-- The size of a t_uscalar_t plus offset is
greater than the len member for the buffer
specified through ctlbuf.
-- The offset member does not specify a prop-
erly-aligned location in the data buffer.
-- An undefined value is stored in flags.
ENXIO Hangup received on the STREAM identified by either
the fildes argument or the fildes member of the
strfdinsert structure.
ERANGE The len member for the buffer specified through
databuf does not fall within the range specified by
the maximum and minimum packet sizes of the topmost
STREAM module; or the len member for the buffer
specified through databuf is larger than the maximum
configured size of the data part of a message; or
the len member for the buffer specified through ctl-
buf is larger than the maximum configured size of
the control part of a message.
I_STR Constructs an internal STREAMS ioctl() message from the
data pointed to by arg, and sends that message downstream.
This mechanism is provided to send ioctl() requests to
downstream modules and drivers. It allows information to be
sent with ioctl(), and returns to the process any informa-
tion sent upstream by the downstream recipient. I_STR shall
block until the system responds with either a positive or
negative acknowledgement message, or until the request
times out after some period of time. If the request times
out, it shall fail with errno set to [ETIME].
At most, one I_STR can be active on a STREAM. Further I_STR
calls shall block until the active I_STR completes at the
STREAM head. The default timeout interval for these
requests is 15 seconds. The O_NONBLOCK flag has no effect
on this call.
To send requests downstream, the application shall ensure
that arg points to a strioctl structure.
The ic_cmd member is the internal ioctl() command intended
for a downstream module or driver and ic_timout is the num-
ber of seconds (-1=infinite, 0=use implementation-defined
timeout interval, >0=as specified) an I_STR request shall
wait for acknowledgement before timing out. ic_len is the
number of bytes in the data argument, and ic_dp is a
pointer to the data argument. The ic_len member has two
uses: on input, it contains the length of the data argument
passed in, and on return from the command, it contains the
number of bytes being returned to the process (the buffer
pointed to by ic_dp should be large enough to contain the
maximum amount of data that any module or the driver in the
STREAM can return).
The STREAM head shall convert the information pointed to by
the strioctl structure to an internal ioctl() command mes-
sage and send it downstream.
The ioctl() function with the I_STR command shall fail if:
EAGAIN or ENOSR
Unable to allocate buffers for the ioctl() message.
EINVAL The ic_len member is less than 0 or larger than the
maximum configured size of the data part of a mes-
sage, or ic_timout is less than -1.
ENXIO Hangup received on fildes.
ETIME A downstream ioctl() timed out before acknowledge-
ment was received.
An I_STR can also fail while waiting for an acknowledgement
if a message indicating an error or a hangup is received at
the STREAM head. In addition, an error code can be
returned in the positive or negative acknowledgement mes-
sage, in the event the ioctl() command sent downstream
fails. For these cases, I_STR shall fail with errno set to
the value in the message.
I_SWROPT Sets the write mode using the value of the argument arg.
Valid bit settings for arg are:
SNDZERO Send a zero-length message downstream when a
write() of 0 bytes occurs. To not send a zero-
length message when a write() of 0 bytes
occurs, the application shall ensure that this
bit is not set in arg (for example, arg would
be set to 0).
The ioctl() function with the I_SWROPT command shall fail
if:
EINVAL arg is not the above value.
I_GWROPT Returns the current write mode setting, as described above,
in the int that is pointed to by the argument arg.
I_SENDFD Creates a new reference to the open file description asso-
ciated with the file descriptor arg, and writes a message
on the STREAMS-based pipe fildes containing this reference,
together with the user ID and group ID of the calling
process.
The ioctl() function with the I_SENDFD command shall fail
if:
EAGAIN The sending STREAM is unable to allocate a message
block to contain the file pointer; or the read queue
of the receiving STREAM head is full and cannot
accept the message sent by I_SENDFD.
EBADF The arg argument is not a valid, open file descrip-
tor.
EINVAL The fildes argument is not connected to a STREAM
pipe.
ENXIO Hangup received on fildes.
The ioctl() function with the I_SENDFD command may fail if:
EINVAL The arg argument is equal to the fildes argument.
I_RECVFD Retrieves the reference to an open file description from a
message written to a STREAMS-based pipe using the I_SENDFD
command, and allocates a new file descriptor in the calling
process that refers to this open file description. The arg
argument is a pointer to a strrecvfd data structure as
defined in <stropts.h>.
The fd member is a file descriptor. The uid and gid members
are the effective user ID and effective group ID, respec-
tively, of the sending process.
If O_NONBLOCK is not set, I_RECVFD shall block until a mes-
sage is present at the STREAM head. If O_NONBLOCK is set,
I_RECVFD shall fail with errno set to [EAGAIN] if no mes-
sage is present at the STREAM head.
If the message at the STREAM head is a message sent by an
I_SENDFD, a new file descriptor shall be allocated for the
open file descriptor referenced in the message. The new
file descriptor is placed in the fd member of the strrecvfd
structure pointed to by arg.
The ioctl() function with the I_RECVFD command shall fail
if:
EAGAIN A message is not present at the STREAM head read
queue and the O_NONBLOCK flag is set.
EBADMSG
The message at the STREAM head read queue is not a
message containing a passed file descriptor.
EMFILE All file descriptors available to the process are
currently open.
ENXIO Hangup received on fildes.
I_LIST Allows the process to list all the module names on the
STREAM, up to and including the topmost driver name. If arg
is a null pointer, the return value shall be the number of
modules, including the driver, that are on the STREAM
pointed to by fildes. This lets the process allocate
enough space for the module names. Otherwise, it should
point to a str_list structure.
The sl_nmods member indicates the number of entries the
process has allocated in the array. Upon return, the
sl_modlist member of the str_list structure shall contain
the list of module names, and the number of entries that
have been filled into the sl_modlist array is found in the
sl_nmods member (the number includes the number of modules
including the driver). The return value from ioctl() shall
be 0. The entries are filled in starting at the top of the
STREAM and continuing downstream until either the end of
the STREAM is reached, or the number of requested modules
(sl_nmods) is satisfied.
The ioctl() function with the I_LIST command shall fail if:
EINVAL The sl_nmods member is less than 1.
EAGAIN or ENOSR
Unable to allocate buffers.
I_ATMARK Allows the process to see if the message at the head of the
STREAM head read queue is marked by some module downstream.
The arg argument determines how the checking is done when
there may be multiple marked messages on the STREAM head
read queue. It may take on the following values:
ANYMARK Check if the message is marked.
LASTMARK Check if the message is the last one marked on
the queue.
The bitwise-inclusive OR of the flags ANYMARK and LASTMARK
is permitted.
The return value shall be 1 if the mark condition is satis-
fied; otherwise, the value shall be 0.
The ioctl() function with the I_ATMARK command shall fail
if:
EINVAL Invalid arg value.
I_CKBAND Checks if the message of a given priority band exists on
the STREAM head read queue. This shall return 1 if a mes-
sage of the given priority exists, 0 if no such message
exists, or -1 on error. arg should be of type int.
The ioctl() function with the I_CKBAND command shall fail
if:
EINVAL Invalid arg value.
I_GETBAND Returns the priority band of the first message on the
STREAM head read queue in the integer referenced by arg.
The ioctl() function with the I_GETBAND command shall fail
if:
ENODATA
No message on the STREAM head read queue.
I_CANPUT Checks if a certain band is writable. arg is set to the
priority band in question. The return value shall be 0 if
the band is flow-controlled, 1 if the band is writable, or
-1 on error.
The ioctl() function with the I_CANPUT command shall fail
if:
EINVAL Invalid arg value.
I_SETCLTIME This request allows the process to set the time the STREAM
head shall delay when a STREAM is closing and there is data
on the write queues. Before closing each module or driver,
if there is data on its write queue, the STREAM head shall
delay for the specified amount of time to allow the data to
drain. If, after the delay, data is still present, it shall
be flushed. The arg argument is a pointer to an integer
specifying the number of milliseconds to delay, rounded up
to the nearest valid value. If I_SETCLTIME is not performed
on a STREAM, an implementation-defined default timeout
interval is used.
The ioctl() function with the I_SETCLTIME command shall
fail if:
EINVAL Invalid arg value.
I_GETCLTIME Returns the close time delay in the integer pointed to by
arg.
Multiplexed STREAMS Configurations
The following commands are used for connecting and disconnecting multi-
plexed STREAMS configurations. These commands use an implementation-
defined default timeout interval.
I_LINK Connects two STREAMs, where fildes is the file descriptor
of the STREAM connected to the multiplexing driver, and arg
is the file descriptor of the STREAM connected to another
driver. The STREAM designated by arg is connected below the
multiplexing driver. I_LINK requires the multiplexing
driver to send an acknowledgement message to the STREAM
head regarding the connection. This call shall return a
multiplexer ID number (an identifier used to disconnect the
multiplexer; see I_UNLINK) on success, and -1 on failure.
The ioctl() function with the I_LINK command shall fail if:
ENXIO Hangup received on fildes.
ETIME Timeout before acknowledgement message was received
at STREAM head.
EAGAIN or ENOSR
Unable to allocate STREAMS storage to perform the
I_LINK.
EBADF The arg argument is not a valid, open file descrip-
tor.
EINVAL The fildes argument does not support multiplexing;
or arg is not a STREAM or is already connected down-
stream from a multiplexer; or the specified I_LINK
operation would connect the STREAM head in more than
one place in the multiplexed STREAM.
An I_LINK can also fail while waiting for the multiplexing
driver to acknowledge the request, if a message indicating
an error or a hangup is received at the STREAM head of
fildes. In addition, an error code can be returned in the
positive or negative acknowledgement message. For these
cases, I_LINK fails with errno set to the value in the mes-
sage.
I_UNLINK Disconnects the two STREAMs specified by fildes and arg.
fildes is the file descriptor of the STREAM connected to
the multiplexing driver. The arg argument is the multi-
plexer ID number that was returned by the I_LINK ioctl()
command when a STREAM was connected downstream from the
multiplexing driver. If arg is MUXID_ALL, then all STREAMs
that were connected to fildes shall be disconnected. As in
I_LINK, this command requires acknowledgement.
The ioctl() function with the I_UNLINK command shall fail
if:
ENXIO Hangup received on fildes.
ETIME Timeout before acknowledgement message was received
at STREAM head.
EAGAIN or ENOSR
Unable to allocate buffers for the acknowledgement
message.
EINVAL Invalid multiplexer ID number.
An I_UNLINK can also fail while waiting for the multiplex-
ing driver to acknowledge the request if a message indicat-
ing an error or a hangup is received at the STREAM head of
fildes. In addition, an error code can be returned in the
positive or negative acknowledgement message. For these
cases, I_UNLINK shall fail with errno set to the value in
the message.
I_PLINK Creates a persistent connection between two STREAMs, where
fildes is the file descriptor of the STREAM connected to
the multiplexing driver, and arg is the file descriptor of
the STREAM connected to another driver. This call shall
create a persistent connection which can exist even if the
file descriptor fildes associated with the upper STREAM to
the multiplexing driver is closed. The STREAM designated
by arg gets connected via a persistent connection below the
multiplexing driver. I_PLINK requires the multiplexing
driver to send an acknowledgement message to the STREAM
head. This call shall return a multiplexer ID number (an
identifier that may be used to disconnect the multiplexer;
see I_PUNLINK) on success, and -1 on failure.
The ioctl() function with the I_PLINK command shall fail
if:
ENXIO Hangup received on fildes.
ETIME Timeout before acknowledgement message was received
at STREAM head.
EAGAIN or ENOSR
Unable to allocate STREAMS storage to perform the
I_PLINK.
EBADF The arg argument is not a valid, open file descrip-
tor.
EINVAL The fildes argument does not support multiplexing;
or arg is not a STREAM or is already connected down-
stream from a multiplexer; or the specified I_PLINK
operation would connect the STREAM head in more than
one place in the multiplexed STREAM.
An I_PLINK can also fail while waiting for the multiplexing
driver to acknowledge the request, if a message indicating
an error or a hangup is received at the STREAM head of
fildes. In addition, an error code can be returned in the
positive or negative acknowledgement message. For these
cases, I_PLINK shall fail with errno set to the value in
the message.
I_PUNLINK Disconnects the two STREAMs specified by fildes and arg
from a persistent connection. The fildes argument is the
file descriptor of the STREAM connected to the multiplexing
driver. The arg argument is the multiplexer ID number that
was returned by the I_PLINK ioctl() command when a STREAM
was connected downstream from the multiplexing driver. If
arg is MUXID_ALL, then all STREAMs which are persistent
connections to fildes shall be disconnected. As in I_PLINK,
this command requires the multiplexing driver to acknowl-
edge the request.
The ioctl() function with the I_PUNLINK command shall fail
if:
ENXIO Hangup received on fildes.
ETIME Timeout before acknowledgement message was received
at STREAM head.
EAGAIN or ENOSR
Unable to allocate buffers for the acknowledgement
message.
EINVAL Invalid multiplexer ID number.
An I_PUNLINK can also fail while waiting for the multiplex-
ing driver to acknowledge the request if a message indicat-
ing an error or a hangup is received at the STREAM head of
fildes. In addition, an error code can be returned in the
positive or negative acknowledgement message. For these
cases, I_PUNLINK shall fail with errno set to the value in
the message.
RETURN VALUE
Upon successful completion, ioctl() shall return a value other than -1
that depends upon the STREAMS device control function. Otherwise, it
shall return -1 and set errno to indicate the error.
ERRORS
Under the following general conditions, ioctl() shall fail if:
EBADF The fildes argument is not a valid open file descriptor.
EINTR A signal was caught during the ioctl() operation.
EINVAL The STREAM or multiplexer referenced by fildes is linked
(directly or indirectly) downstream from a multiplexer.
If an underlying device driver detects an error, then ioctl() shall
fail if:
EINVAL The request or arg argument is not valid for this device.
EIO Some physical I/O error has occurred.
ENOTTY The file associated with the fildes argument is not a STREAMS
device that accepts control functions.
ENXIO The request and arg arguments are valid for this device driver,
but the service requested cannot be performed on this particular
sub-device.
ENODEV The fildes argument refers to a valid STREAMS device, but the
corresponding device driver does not support the ioctl() func-
tion.
If a STREAM is connected downstream from a multiplexer, any ioctl()
command except I_UNLINK and I_PUNLINK shall set errno to [EINVAL].
The following sections are informative.
EXAMPLES
None.
APPLICATION USAGE
The implementation-defined timeout interval for STREAMS has histori-
cally been 15 seconds.
RATIONALE
None.
FUTURE DIRECTIONS
The ioctl() function may be removed in a future version.
SEE ALSO
Section 2.6, STREAMS, close(), fcntl(), getmsg(), open(), pipe(),
poll(), putmsg(), read(), sigaction(), write()
The Base Definitions volume of POSIX.1-2008, <stropts.h>
COPYRIGHT
Portions of this text are reprinted and reproduced in electronic form
from IEEE Std 1003.1, 2013 Edition, Standard for Information Technology
-- Portable Operating System Interface (POSIX), The Open Group Base
Specifications Issue 7, Copyright (C) 2013 by the Institute of Electri-
cal and Electronics Engineers, Inc and The Open Group. (This is
POSIX.1-2008 with the 2013 Technical Corrigendum 1 applied.) In the
event of any discrepancy between this version and the original IEEE and
The Open Group Standard, the original IEEE and The Open Group Standard
is the referee document. The original Standard can be obtained online
at http://www.unix.org/online.html .
Any typographical or formatting errors that appear in this page are
most likely to have been introduced during the conversion of the source
files to man page format. To report such errors, see https://www.ker-
nel.org/doc/man-pages/reporting_bugs.html .
IEEE/The Open Group 2013 IOCTL(3P)
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