Manual Reference Pages  - <stropts.h> (P)

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.

CONTENTS

Name
Synopsis
Description
Application Usage
Rationale
Future Directions
See Also
Copyright

NAME

stropts.h - STREAMS interface (STREAMS)

SYNOPSIS

#include <stropts.h>

DESCRIPTION

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

unsigned char bi_pri Priority band. int bi_flag Flushing type.

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

int maxlen Maximum buffer length. int len Length of data. char *buf Pointer to buffer.

The <stropts.h> header shall define the strfdinsert structure that includes 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. int fildes File descriptor of the other STREAM. int offset Relative location of the stored value.

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

int ic_cmd ioctl() command. int ic_timout Timeout for response. int ic_len Length of data. char *ic_dp Pointer to buffer.

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

int fda Received file descriptor. uid_t uid UID of sender. gid_t gid GID of sender.

The uid_t and gid_t types shall be defined 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 that includes at least the following members:

int sl_nmods Number of STREAMS module names. struct str_mlist *sl_modlist STREAMS module names.

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

char l_name[FMNAMESZ+1] A STREAMS module name.

At least the following macros shall be defined for use as the request argument to ioctl():
I_PUSH Push a STREAMS module.
I_POP Pop a STREAMS module.
I_LOOK Get the top module name.
I_FLUSH Flush a STREAM.
I_FLUSHBAND
  Flush one band of a STREAM.
I_SETSIG
  Ask for notification signals.
I_GETSIG
  Retrieve current notification signals.
I_FIND Look for a STREAMS module.
I_PEEK Peek at the top message on a STREAM.
I_SRDOPT
  Set the read mode.
I_GRDOPT
  Get the read mode.
I_NREAD Size the top message.
I_FDINSERT
  Send implementation-defined information about another STREAM.
I_STR Send a STREAMS ioctl().
I_SWROPT
  Set the write mode.
I_GWROPT
  Get the write mode.
I_SENDFD
  Pass a file descriptor through a STREAMS pipe.
I_RECVFD
  Get a file descriptor sent via I_SENDFD.
I_LIST Get all the module names on a STREAM.
I_ATMARK
  Is the top message "marked’’?
I_CKBAND
  See if any messages exist in a band.
I_GETBAND
  Get the band of the top message on a STREAM.
I_CANPUT
  Is a band writable?
I_SETCLTIME
  Set close time delay.
I_GETCLTIME
  Get close time delay.
I_LINK Connect two STREAMs.
I_UNLINK
  Disconnect two STREAMs.
I_PLINK Persistently connect two STREAMs.
I_PUNLINK
  Dismantle a persistent STREAMS link.

At least the following macros shall be defined for use with I_LOOK:
FMNAMESZ
  The minimum size in bytes of the buffer referred to by the arg argument.

At least the following macros shall be defined for use with I_FLUSH:
FLUSHR Flush read queues.
FLUSHW Flush write queues.
FLUSHRW Flush read and write queues.

At least the following macros shall be defined for use with I_SETSIG:
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
  Equivalent to 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.

At least the following macros shall be defined for use with I_PEEK:
RS_HIPRI
  Only look for high-priority messages.

At least the following macros shall be defined for use with I_SRDOPT:
RNORM Byte-STREAM mode, the default.
RMSGD Message-discard mode.
RMSGN Message-non-discard 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().

At least the following macros shall be defined for use with I_SWOPT:
SNDZERO Send a zero-length message downstream when a write() of 0 bytes occurs.

At least the following macros shall be defined 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.

At least the following macros shall be defined for use with I_UNLINK:
MUXID_ALL
  Unlink all STREAMs linked to the STREAM associated with fildes.

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

The following shall be declared as functions and may also be defined as macros. Function prototypes shall be provided.

int isastream(int); 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 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 *);

The following sections are informative.

APPLICATION USAGE

None.

RATIONALE

None.

FUTURE DIRECTIONS

None.

SEE ALSO

<sys/types.h> , <unistd.h> , the System Interfaces volume of IEEE Std 1003.1-2001, close(), fcntl(), getmsg(), ioctl(), open(), pipe(), read(), poll(), putmsg(), signal(), write()

COPYRIGHT

Portions of this text are reprinted and reproduced in electronic form from IEEE Std 1003.1, 2003 Edition, Standard for Information Technology -- Portable Operating System Interface (POSIX), The Open Group Base Specifications Issue 6, Copyright (C) 2001-2003 by the Institute of Electrical and Electronics Engineers, Inc and The Open Group. 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.opengroup.org/unix/online.html .


IEEE/The Open Group <stropts.h> (P) 2003
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