'\" et .TH stropts.h "0P" 2017 "IEEE/The Open Group" "POSIX Programmer's Manual" .\" .SH 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. .\" .SH NAME stropts.h \(em STREAMS interface (\fBSTREAMS\fP) .SH SYNOPSIS .LP .nf #include .fi .SH DESCRIPTION The .IR header shall define the .BR bandinfo structure, which shall include at least the following members: .sp .RS 4 .nf int bi_flag \fRFlushing type.\fR unsigned char bi_pri \fRPriority band.\fR .fi .P .RE .P The .IR header shall define the .BR strpeek structure, which shall include at least the following members: .sp .RS 4 .nf struct strbuf ctlbuf \fRThe control portion of the message.\fR struct strbuf databuf \fRThe data portion of the message.\fR t_uscalar_t flags \fRRS_HIPRI or 0.\fR .fi .P .RE .P The .IR header shall define the .BR strbuf structure, which shall include at least the following members: .sp .RS 4 .nf char *buf \fRPointer to buffer.\fP int len \fRLength of data.\fP int maxlen \fRMaximum buffer length.\fP .fi .P .RE .P The .IR header shall define the .BR strfdinsert structure, which shall include at least the following members: .sp .RS 4 .nf struct strbuf ctlbuf \fRThe control portion of the message.\fR struct strbuf databuf \fRThe data portion of the message.\fR int fildes \fRFile descriptor of the other STREAM.\fR t_uscalar_t flags \fRRS_HIPRI or 0.\fR int offset \fRRelative location of the stored value.\fR .fi .P .RE .P The .IR header shall define the .BR strioctl structure, which shall include at least the following members: .sp .RS 4 .nf int ic_cmd \fIioctl\fR(\|) command.\fR char *ic_dp \fRPointer to buffer.\fR int ic_len \fRLength of data.\fR int ic_timout \fRTimeout for response.\fR .fi .P .RE .P The .IR header shall define the .BR strrecvfd structure, which shall include at least the following members: .sp .RS 4 .nf int fd \fRReceived file descriptor.\fR gid_t gid \fRGID of sender.\fR uid_t uid \fRUID of sender.\fR .fi .P .RE .P The .IR header shall define the .BR uid_t and .BR gid_t types through .BR typedef , as described in .IR . .P The .IR header shall define the .BR t_scalar_t and .BR t_uscalar_t types, respectively, as signed and unsigned opaque types of equal length of at least 32 bits. .P The .IR header shall define the .BR str_list structure, which shall include at least the following members: .sp .RS 4 .nf struct str_mlist *sl_modlist \fRSTREAMS module names.\fR int sl_nmods \fRNumber of STREAMS module names.\fR .fi .P .RE .P The .IR header shall define the .BR str_mlist structure, which shall include at least the following member: .sp .RS 4 .nf char l_name[FMNAMESZ+1] \fRA STREAMS module name.\fR .fi .P .RE .P The .IR header shall define at least the following symbolic constants for use as the .IR request argument to \fIioctl\fR(): .IP I_ATMARK 12 Is the top message ``marked''? .IP I_CANPUT 12 Is a band writable? .IP I_CKBAND 12 See if any messages exist in a band. .IP I_FDINSERT 12 Send implementation-defined information about another STREAM. .IP I_FIND 12 Look for a STREAMS module. .IP I_FLUSH 12 Flush a STREAM. .IP I_FLUSHBAND 12 Flush one band of a STREAM. .IP I_GETBAND 12 Get the band of the top message on a STREAM. .IP I_GETCLTIME 12 Get close time delay. .IP I_GETSIG 12 Retrieve current notification signals. .IP I_GRDOPT 12 Get the read mode. .IP I_GWROPT 12 Get the write mode. .IP I_LINK 12 Connect two STREAMs. .IP I_LIST 12 Get all the module names on a STREAM. .IP I_LOOK 12 Get the top module name. .IP I_NREAD 12 Size the top message. .IP I_PEEK 12 Peek at the top message on a STREAM. .IP I_PLINK 12 Persistently connect two STREAMs. .IP I_POP 12 Pop a STREAMS module. .IP I_PUNLINK 12 Dismantle a persistent STREAMS link. .IP I_PUSH 12 Push a STREAMS module. .IP I_RECVFD 12 Get a file descriptor sent via I_SENDFD. .IP I_SENDFD 12 Pass a file descriptor through a STREAMS pipe. .IP I_SETCLTIME 12 Set close time delay. .IP I_SETSIG 12 Ask for notification signals. .IP I_SRDOPT 12 Set the read mode. .IP I_STR 12 Send a STREAMS \fIioctl\fR(). .IP I_SWROPT 12 Set the write mode. .IP I_UNLINK 12 Disconnect two STREAMs. .P The .IR header shall define at least the following symbolic constant for use with I_LOOK: .IP FMNAMESZ 12 The minimum size in bytes of the buffer referred to by the .IR arg argument. .P The .IR header shall define at least the following symbolic constants for use with I_FLUSH: .IP FLUSHR 12 Flush read queues. .IP FLUSHRW 12 Flush read and write queues. .IP FLUSHW 12 Flush write queues. .P The .IR header shall define at least the following symbolic constants for use with I_SETSIG: .IP S_BANDURG 12 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. .IP S_ERROR 12 Notification of an error condition reaches the STREAM head. .IP S_HANGUP 12 Notification of a hangup reaches the STREAM head. .IP S_HIPRI 12 A high-priority message is present on a STREAM head read queue. .IP S_INPUT 12 A message, other than a high-priority message, has arrived at the head of a STREAM head read queue. .IP S_MSG 12 A STREAMS signal message that contains the SIGPOLL signal reaches the front of the STREAM head read queue. .IP S_OUTPUT 12 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. .IP S_RDBAND 12 A message with a non-zero priority band has arrived at the head of a STREAM head read queue. .IP S_RDNORM 12 A normal (priority band set to 0) message has arrived at the head of a STREAM head read queue. .IP S_WRBAND 12 The write queue for a non-zero priority band just below the STREAM head is no longer full. .IP S_WRNORM 12 Equivalent to S_OUTPUT. .P The .IR header shall define at least the following symbolic constant for use with I_PEEK: .IP RS_HIPRI 12 Only look for high-priority messages. .P The .IR header shall define at least the following symbolic constants for use with I_SRDOPT: .IP RMSGD 12 Message-discard mode. .IP RMSGN 12 Message-non-discard mode. .IP RNORM 12 Byte-STREAM mode, the default. .IP RPROTDAT 12 Deliver the control part of a message as data when a process issues a \fIread\fR(). .IP RPROTDIS 12 Discard the control part of a message, delivering any data part, when a process issues a \fIread\fR(). .IP RPROTNORM 12 Fail \fIread\fR() with .BR [EBADMSG] if a message containing a control part is at the front of the STREAM head read queue. .P The .IR header shall define at least the following symbolic constant for use with I_SWOPT: .IP SNDZERO 12 Send a zero-length message downstream when a \fIwrite\fR() of 0 bytes occurs. .P The .IR header shall define at least the following symbolic constants for use with I_ATMARK: .IP ANYMARK 12 Check if the message is marked. .IP LASTMARK 12 Check if the message is the last one marked on the queue. .P The .IR header shall define at least the following symbolic constant for use with I_UNLINK: .IP MUXID_ALL 12 Unlink all STREAMs linked to the STREAM associated with .IR fildes . .P The .IR header shall define the following symbolic constants for \fIgetmsg\fR(), \fIgetpmsg\fR(), \fIputmsg\fR(), and \fIputpmsg\fR(): .IP MORECTL 12 More control information is left in message. .IP MOREDATA 12 More data is left in message. .IP MSG_ANY 12 Receive any message. .IP MSG_BAND 12 Receive message from specified band. .IP MSG_HIPRI 12 Send/receive high-priority message. .P The .IR header may make visible all of the symbols from .IR . .P The .IR header may also define macros for message types using names that start with .IR M_ . .P The following shall be declared as functions and may also be defined as macros. Function prototypes shall be provided. .sp .RS 4 .nf 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); .fi .P .RE .LP .IR "The following sections are informative." .SH "APPLICATION USAGE" None. .SH RATIONALE None. .SH "FUTURE DIRECTIONS" None. .SH "SEE ALSO" .IR "\fB\fP", .IR "\fB\fP" .P The System Interfaces volume of POSIX.1\(hy2017, .IR "\fIclose\fR\^(\|)", .IR "\fIfattach\fR\^(\|)", .IR "\fIfcntl\fR\^(\|)", .IR "\fIfdetach\fR\^(\|)", .IR "\fIgetmsg\fR\^(\|)", .IR "\fIioctl\fR\^(\|)", .IR "\fIisastream\fR\^(\|)", .IR "\fIopen\fR\^(\|)", .IR "\fIpipe\fR\^(\|)", .IR "\fIread\fR\^(\|)", .IR "\fIpoll\fR\^(\|)", .IR "\fIputmsg\fR\^(\|)", .IR "\fIsignal\fR\^(\|)", .IR "\fIwrite\fR\^(\|)" .\" .SH 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 . .PP 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 .