STROPTS.H(7) Miscellaneous Information Manual STROPTS.H(7)

stropts.h — STREAMS interface

#include <stropts.h>

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 structure that includes at least the following members: struct strbuf ctlbuf struct strbuf databuf t_uscalar_t flags

The <stropts.h> header defines the 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 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 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 structure that includes at least the following members: int fd uid_t uid gid_t gid

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

The type is defined as described in <xti.h> in the referenced specification.

The <stropts.h> header defines the structure that includes at least the following members: int sl_nmods struct str_mlist *sl_modlist

The <stropts.h> header defines the structure that includes at least the following member: char l_name[FMNAMESZ+1]

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

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

Flush read queues.
Flush write queues.
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 and ) when a particular event has occurred on the STREAM.

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

A normal (priority band set to 0) message has arrived at the head of a STREAM head read queue.
A message with a non-zero priority band has arrived at the head of a STREAM head read queue.
A message, other than a high-priority message, has arrived at the head of a STREAM head read queue.
A high-priority message is present on a STREAM head read queue.
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.
Same as S_OUTPUT.
The write queue for a non-zero priority band just below the STREAM head is no longer full.
A STREAMS signal message that contains the SIGPOLL signal reaches the front of the STREAM head read queue.
Notification of an error condition reaches the STREAM head.
Notification of a hangup reaches the STREAM head.
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:

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:

Byte-STREAM mode, the default.
Message-discard mode.
Message-nondiscard mode.
Fail read(3) with [EBADMSG] if a message containing a control part is at the front of the STREAM head read queue.
Deliver the control part of a message as data when a process issues a read(3) .
Discard the control part of a message, delivering any data part, when a process issues a read(3) .

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:

Send a zero-length message downstream when a write(3) of 0 bytes occurs.

I_GWROPT Returns the current write mode setting.

I_SENDFD Requests the STREAM associated with 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:

Check if the message is marked.
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:

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 , , and :

Receive any message.
Receive message from specified band.
Send/Receive high priority message.
More control information is left in message.
More data is left in message.

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

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 *);

None.

None.

close(3) , fcntl(3) , getmsg(3) , ioctl(3) , open(3) , pipe(3) , read(3) , poll(3) , putmsg(3) , signal(3) , sigset(3) , write(3) , <xti.h> .

February 1997 posix.fail