NAME

stropts.h - STREAMS interface

 SYNOPSIS

#include <stropts.h>

 DESCRIPTION

The <stropts.h> header defines the bandinfo structure that includes at least the following members:

unsigned char bi_pri
int           bi_flag

The <stropts.h> header defines the strpeek structure that includes at least the following members:

struct strbuf ctlbuf
struct strbuf databuf
t_uscalar_t   flags

The <stropts.h> header defines the strbuf structure that includes at least the following members:

int           maxlen     maximum buffer length
int           len        length of data
char         *buf        ptr to buffer

The <stropts.h> header defines the strfdinsert structure that includes at least the following members:

struct strbuf ctlbuf
struct strbuf databuf
t_uscalar_t   flags
int           fildes
int           offset

The <stropts.h> header defines the strioctl structure that includes at least the following members:

int           ic_cmd
int           ic_timout
int           ic_len
char         *ic_dp

The <stropts.h> header defines the strrecvfd structure that includes at least the following members:

int           fd
uid_t         uid
gid_t         gid

The uid_t and gid_t types are defined through typedef as described in <sys/types.h>.

The t_uscalar_t type is defined as described in <xti.h> in the referenced Networking Services, Issue 5 specification.

The <stropts.h> header defines the str_list structure that includes at least the following members:

int               sl_nmods
struct str_mlist *sl_modlist

The <stropts.h> header defines the str_mlist structure that includes at least the following member:

char          l_name[FMNAMESZ+1]

At least the following macros are defined for use as the request argument to ioctl():

I_PUSH

Push STREAMS module onto the top of the current STREAM, just below the STREAM head.

I_POP

Remove STREAMS module from just below the STREAM head.

I_LOOK

Retrieve the name of the module just below the STREAM head and place it in a character string. At least the following macros are defined for use as the arg argument:

FMNAMESZ

The minimum size in bytes of the buffer referred to by the arg argument.

I_FLUSH

This request flushes all input and/or output queues, depending on the value of the arg argument. At least the following macros are defined for use as the arg argument:

FLUSHR

Flush read queues.

FLUSHW

Flush write queues.

FLUSHRW

Flush read and write queues.

I_FLUSHBAND

Flush only band specified.

I_SETSIG

Informs the STREAM head that the process wants the SIGPOLL signal issued (see signal() and sigset()) when a particular event has occurred on the STREAM.

The header <stropts.h> defines these possible values for arg when I_SETSIG is specified:

S_RDNORM

A normal (priority band set to 0) message has arrived at the head of a STREAM head read queue.

S_RDBAND

A message with a non-zero priority band has arrived at the head of a STREAM head read queue.

S_INPUT

A message, other than a high-priority message, has arrived at the head of a STREAM head read queue.

S_HIPRI

A high-priority message is present on a STREAM head read queue.

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) normal data downstream.

S_WRNORM

Same as S_OUTPUT.

S_WRBAND

The write queue for a non-zero priority band just below the STREAM head is no longer full.

S_MSG

A STREAMS signal message that contains the SIGPOLL signal reaches the front of the STREAM head read queue.

S_ERROR

Notification of an error condition reaches the STREAM head.

S_HANGUP

Notification of a hangup reaches 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.

I_GETSIG

Returns the events for which the calling process is currently registered to be sent a SIGPOLL signal.

I_FIND

Compares the names of all modules currently present in the STREAM to the name pointed to by arg.

I_PEEK

Allows a process to retrieve the information in the first message on the STREAM head read queue without taking the message off the queue. At least the following macros are defined for use as the arg argument:

RS_HIPRI

Only look for high-priority messages.

I_SRDOPT

Sets the read mode. At least the following macros are defined for use as the arg argument:

RNORM

Byte-STREAM mode, the default.

RMSGD

Message-discard mode.

RMSGN

Message-nondiscard mode.

RPROTNORM

Fail read() with [EBADMSG] if a message containing 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, delivering any data part, when a process issues a read().

I_GRDOPT

Returns the current read mode setting.

I_NREAD

Counts the number of data bytes in data blocks in the first message on the STREAM head read queue.

I_FDINSERT

Creates a message from the specified buffer(s), adds information about another STREAM, and sends the message downstream.

I_STR

Constructs an internal STREAMS ioctl() message and sends that message downstream.

I_SWROPT

Sets the write mode. At least the following macros are defined for use as the arg argument:

SNDZERO

Send a zero-length message downstream when a write() of 0 bytes occurs.

I_GWROPT

Returns the current write mode setting.

I_SENDFD

Requests the STREAM associated with fildes to send a message, containing a file pointer, to the STREAM head at the other end of a STREAMS pipe.

I_RECVFD

Retrieves the file descriptor associated with the message sent by an I_SENDFD ioctl() over a STREAMS pipe.

I_LIST

This request allows the process to list all the module names on the STREAM, up to and including the topmost driver name.

I_ATMARK

This request allows the process to see if the current message on the STREAM head read queue is "marked" by some module downstream. At least the following macros are defined for use as the arg argument:

ANYMARK

Check if the message is marked.

LASTMARK

Check if the message is the last one marked on the queue.

I_CKBAND

Check if the message of a given priority band exists on the STREAM head read queue.

I_GETBAND

Return the priority band of the first message on the STREAM head read queue.

I_CANPUT

Check if a certain band is writable.

I_SETCLTIME

Allows the process to set the time the STREAM head will delay when a STREAM is closing and there is data on the write queues.

I_GETCLTIME

Returns the close time delay.

I_LINK

Connects two STREAMs.

I_UNLINK

Disconnects the two STREAMs. The header defines at least the following value for arg:

MUXID_ALL

Unlink all STREAMs linked to the STREAM associated with fildes.

I_PLINK

Connects two STREAMs with a persistent link.

I_PUNLINK

Disconnects the two STREAMs that were connected with a persistent link.

The following macros are defined for getmsg(), getpmsg(), putmsg() and putpmsg():

MSG_ANY

Receive any message.

MSG_BAND

Receive message from specified band.

MSG_HIPRI

Send/Receive high priority message.

MORECTL

More control information is left in message.

MOREDATA

More data is left in message.

The header <stropts.h> may make visible all of the symbols from <unistd.h>.

The following are declared as functions in the <stropts.h> header and may also be defined as macros. Function prototypes must be provided for use with an ISO C compiler.

int    isastream(int);
int    getmsg(int, struct strbuf *, struct strbuf *, int *);
int    getpmsg(int, struct strbuf *, struct strbuf *, int *, int *);
int    ioctl(int, int, ... );
int    putmsg(int, const struct strbuf *, const struct strbuf *, int);
int    putpmsg(int, const struct strbuf *, const struct strbuf *, int,
           int);
int    fattach(int, const char *);
int    fdetach(const char *);

 APPLICATION USAGE

None.

 FUTURE DIRECTIONS

None.

 SEE ALSO

close(), fcntl(), getmsg(), ioctl(), open(), pipe(), read(), poll(), putmsg(), signal(), sigset(), write(), <xti.h>.