Manpages - stropts.h.0p
Table of Contents
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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
stropts.h — STREAMS interface (STREAMS)
SYNOPSIS
#include <stropts.h>
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.
APPLICATION USAGE
None.
RATIONALE
None.
FUTURE DIRECTIONS
None.
SEE ALSO
<sys_types.h>, <unistd.h>
The System Interfaces volume of POSIX.1‐2017, /close ( )/, /fattach ( )/, /fcntl ( )/, /fdetach ( )/, /getmsg ( )/, /ioctl ( )/, /isastream ( )/, /open ( )/, /pipe ( )/, /read ( )/, /poll ( )/, /putmsg ( )/, /signal ( )/, /write ( )/
COPYRIGHT
Portions of this text are reprinted and reproduced in electronic form from IEEE Std 1003.1-2017, Standard for Information Technology – Portable Operating System Interface (POSIX), The Open Group Base Specifications Issue 7, 2018 Edition, Copyright (C) 2018 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 .
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.kernel.org/doc/man-pages/reporting_bugs.html .