интерфейс STREAMS (потоковой передачи данных) (STREAMS interface (STREAMS))
Пролог (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.
Имя (Name)
stropts.h — STREAMS interface (STREAMS)
Синопсис (Synopsis)
#include <stropts.h>
Описание (Description)
The <stropts.h> header shall define the bandinfo structure, which
shall include at least the following members:
int bi_flag Flushing type.
unsigned char bi_pri Priority band.
The <stropts.h> header shall define the strpeek structure, which
shall include at least the following members:
struct strbuf ctlbuf The control portion of the message.
struct strbuf databuf The data portion of the message.
t_uscalar_t flags RS_HIPRI or 0.
The <stropts.h> header shall define the strbuf structure, which
shall include at least the following members:
char *buf Pointer to buffer.
int len Length of data.
int maxlen Maximum buffer length.
The <stropts.h> header shall define the strfdinsert structure,
which shall include at least the following members:
struct strbuf ctlbuf The control portion of the message.
struct strbuf databuf The data portion of the message.
int fildes File descriptor of the other STREAM.
t_uscalar_t flags RS_HIPRI or 0.
int offset Relative location of the stored value.
The <stropts.h> header shall define the strioctl structure, which
shall include at least the following members:
int ic_cmd ioctl() command.
char *ic_dp Pointer to buffer.
int ic_len Length of data.
int ic_timout Timeout for response.
The <stropts.h> header shall define the strrecvfd structure,
which shall include at least the following members:
int fd Received file descriptor.
gid_t gid GID of sender.
uid_t uid UID of sender.
The <stropts.h> header shall define the uid_t and gid_t types
through typedef, as described in <sys/types.h>.
The <stropts.h> header shall define the t_scalar_t and
t_uscalar_t types, respectively, as signed and unsigned opaque
types of equal length of at least 32 bits.
The <stropts.h> header shall define the str_list structure, which
shall include at least the following members:
struct str_mlist *sl_modlist STREAMS module names.
int sl_nmods Number of STREAMS module names.
The <stropts.h> header shall define the str_mlist structure,
which shall include at least the following member:
char l_name[FMNAMESZ+1] A STREAMS module name.
The <stropts.h> header shall define at least the following
symbolic constants for use as the request argument to ioctl():
I_ATMARK Is the top message ``marked''?
I_CANPUT Is a band writable?
I_CKBAND See if any messages exist in a band.
I_FDINSERT Send implementation-defined information about another
STREAM.
I_FIND Look for a STREAMS module.
I_FLUSH Flush a STREAM.
I_FLUSHBAND Flush one band of a STREAM.
I_GETBAND Get the band of the top message on a STREAM.
I_GETCLTIME Get close time delay.
I_GETSIG Retrieve current notification signals.
I_GRDOPT Get the read mode.
I_GWROPT Get the write mode.
I_LINK Connect two STREAMs.
I_LIST Get all the module names on a STREAM.
I_LOOK Get the top module name.
I_NREAD Size the top message.
I_PEEK Peek at the top message on a STREAM.
I_PLINK Persistently connect two STREAMs.
I_POP Pop a STREAMS module.
I_PUNLINK Dismantle a persistent STREAMS link.
I_PUSH Push a STREAMS module.
I_RECVFD Get a file descriptor sent via I_SENDFD.
I_SENDFD Pass a file descriptor through a STREAMS pipe.
I_SETCLTIME Set close time delay.
I_SETSIG Ask for notification signals.
I_SRDOPT Set the read mode.
I_STR Send a STREAMS ioctl().
I_SWROPT Set the write mode.
I_UNLINK Disconnect two STREAMs.
The <stropts.h> header shall define at least the following
symbolic constant for use with I_LOOK:
FMNAMESZ The minimum size in bytes of the buffer referred to
by the arg argument.
The <stropts.h> header shall define at least the following
symbolic constants for use with I_FLUSH:
FLUSHR Flush read queues.
FLUSHRW Flush read and write queues.
FLUSHW Flush write queues.
The <stropts.h> header shall define at least the following
symbolic constants for use with I_SETSIG:
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.
S_ERROR Notification of an error condition reaches the STREAM
head.
S_HANGUP Notification of a hangup reaches the STREAM head.
S_HIPRI A high-priority message is present on 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_MSG A STREAMS signal message that contains the SIGPOLL
signal reaches the front of the 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_RDBAND A message with a non-zero priority band has arrived
at the head of a STREAM head read queue.
S_RDNORM A normal (priority band set to 0) message has arrived
at the head of a STREAM head read queue.
S_WRBAND The write queue for a non-zero priority band just
below the STREAM head is no longer full.
S_WRNORM Equivalent to S_OUTPUT.
The <stropts.h> header shall define at least the following
symbolic constant for use with I_PEEK:
RS_HIPRI Only look for high-priority messages.
The <stropts.h> header shall define at least the following
symbolic constants for use with I_SRDOPT:
RMSGD Message-discard mode.
RMSGN Message-non-discard mode.
RNORM Byte-STREAM mode, the default.
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().
RPROTNORM Fail read() with [EBADMSG] if a message containing a
control part is at the front of the STREAM head read
queue.
The <stropts.h> header shall define at least the following
symbolic constant for use with I_SWOPT:
SNDZERO Send a zero-length message downstream when a write()
of 0 bytes occurs.
The <stropts.h> header shall define at least the following
symbolic constants for use with I_ATMARK:
ANYMARK Check if the message is marked.
LASTMARK Check if the message is the last one marked on the
queue.
The <stropts.h> header shall define at least the following
symbolic constant for use with I_UNLINK:
MUXID_ALL Unlink all STREAMs linked to the STREAM associated
with fildes.
The <stropts.h> header shall define the following symbolic
constants for getmsg(), getpmsg(), putmsg(), and putpmsg():
MORECTL More control information is left in message.
MOREDATA More data is left in message.
MSG_ANY Receive any message.
MSG_BAND Receive message from specified band.
MSG_HIPRI Send/receive high-priority message.
The <stropts.h> header may make visible all of the symbols from
<unistd.h>.
The <stropts.h> header may also define macros for message types
using names that start with M_.
The following shall be declared as functions and may also be
defined as macros. Function prototypes shall be provided.
int fattach(int, const char *);
int fdetach(const char *);
int getmsg(int, struct strbuf *restrict, struct strbuf *restrict,
int *restrict);
int getpmsg(int, struct strbuf *restrict, struct strbuf *restrict,
int *restrict, int *restrict);
int ioctl(int, int, ...);
int isastream(int);
int putmsg(int, const struct strbuf *, const struct strbuf *, int);
int putpmsg(int, const struct strbuf *, const struct strbuf *, int,
int);
The following sections are informative.
Использование в приложениях (Application usage)
None.
Обоснование (Rationale)
None.
Будущие направления (Future directions)
None.
Смотри также (See also)
sys_types.h(0p), unistd.h(0p)
The System Interfaces volume of POSIX.1‐2017, close(3p),
fattach(3p), fcntl(3p), fdetach(3p), getmsg(3p), ioctl(3p),
isastream(3p), open(3p), pipe(3p), read(3p), poll(3p),
putmsg(3p), signal(3p), write(3p)
