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Portions of this text are reprinted and reproduced in electronic form in the Sun OS Reference Manual, from IEEE Std 1003.1, 2004 Edition, Standard for Information Technology -- Portable Operating System Interface (POSIX), The Open Group Base Specifications Issue 6, Copyright (C) 2001-2004 by the Institute of Electrical and Electronics Engineers, Inc and The Open Group. In the event of any discrepancy between these versions 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. .\" This notice shall appear on any product containing this material. .\" The contents of this file are subject to the terms of the Common Development and Distribution License (the "License"). 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If applicable, add the following below this CDDL HEADER, with the fields enclosed by brackets "[]" replaced with your own identifying information: Portions Copyright [yyyy] [name of copyright owner] .TH putmsg 2 "1 Nov 2003" "SunOS 5.11" "System Calls" .SH NAME putmsg, putpmsg \- send a message on a stream .SH SYNOPSIS .LP .nf #include \fBint\fR \fBputmsg\fR(\fBint\fR \fIfildes\fR, \fBconst struct strbuf *\fR\fIctlptr\fR, \fBconst struct strbuf *\fR\fIdataptr\fR, \fBint\fR \fIflags\fR); .fi .LP .nf \fBint\fR \fBputpmsg\fR(\fBint\fR \fIfildes\fR, \fBconst struct strbuf *\fR\fIctlptr\fR, \fBconst struct strbuf *\fR\fIdataptr\fR,\fBint\fR \fIband\fR, \fBint\fR \fIflags\fR); .fi .SH DESCRIPTION .sp .LP The \fBputmsg()\fR function creates a message from user-specified buffer(s) and sends the message to a streams file. The message may contain either a data part, a control part, or both. The data and control parts to be sent are distinguished by placement in separate buffers, as described below. The semantics of each part is defined by the streams module that receives the message. .sp .LP The \fBputpmsg()\fR function does the same thing as \fBputmsg()\fR, but provides the user the ability to send messages in different priority bands. Except where noted, all information pertaining to \fBputmsg()\fR also pertains to \fBputpmsg()\fR. .sp .LP The \fIfildes\fR argument specifies a file descriptor referencing an open stream. The \fIctlptr\fR and \fIdataptr\fR arguments each point to a \fBstrbuf\fR structure, which contains the following members: .sp .in +2 .nf int maxlen; /* not used here */ int len; /* length of data */ void *buf; /* ptr to buffer */ .fi .in -2 .sp .LP The \fIctlptr\fR argument points to the structure describing the control part, if any, to be included in the message. The \fBbuf\fR member in the \fBstrbuf\fR structure points to the buffer where the control information resides, and the \fBlen\fR member indicates the number of bytes to be sent. The \fBmaxlen\fR member is not used in \fBputmsg()\fR (see \fBgetmsg\fR(2)). In a similar manner, \fIdataptr\fR specifies the data, if any, to be included in the message. The \fIflags\fR argument indicates what type of message should be sent and is described later. .sp .LP To send the data part of a message, \fIdataptr\fR must not be \fINULL\fR, and the \fBlen\fR member of \fIdataptr\fR must have a value of 0 or greater. To send the control part of a message, the corresponding values must be set for \fIctlptr\fR. No data (control) part is sent if either \fIdataptr\fR (\fIctlptr\fR) is \fINULL\fR or the \fBlen\fR member of \fIdataptr\fR (\fIctlptr\fR) is negative. .sp .LP For \fBputmsg()\fR, if a control part is specified, and \fIflags\fR is set to \fBRS_HIPRI\fR, a high priority message is sent. If no control part is specified, and \fIflags\fR is set to \fBRS_HIPRI\fR, \fBputmsg()\fR fails and sets \fBerrno\fR to \fBEINVAL\fR. If \fIflags\fR is set to 0, a normal (non-priority) message is sent. If no control part and no data part are specified, and \fIflags\fR is set to 0, no message is sent, and 0 is returned. .sp .LP The stream head guarantees that the control part of a message generated by \fBputmsg()\fR is at least 64 bytes in length. .sp .LP For \fBputpmsg()\fR, the flags are different. The \fIflags\fR argument is a bitmask with the following mutually-exclusive flags defined: \fBMSG_HIPRI\fR and \fBMSG_BAND\fR. If \fIflags\fR is set to 0, \fBputpmsg()\fR fails and sets \fBerrno\fR to \fBEINVAL\fR. If a control part is specified and \fIflags\fR is set to \fBMSG_HIPRI\fR and \fIband\fR is set to 0, a high-priority message is sent. If \fIflags\fR is set to \fBMSG_HIPRI\fR and either no control part is specified or \fIband\fR is set to a non-zero value, \fBputpmsg()\fR fails and sets \fBerrno\fR to \fBEINVAL\fR. If flags is set to \fBMSG_BAND\fR, then a message is sent in the priority band specified by \fIband\fR. If a control part and data part are not specified and \fIflags\fR is set to \fBMSG_BAND\fR, no message is sent and 0 is returned. .sp .LP Normally, \fBputmsg()\fR will block if the stream write queue is full due to internal flow control conditions. For high-priority messages, \fBputmsg()\fR does not block on this condition. For other messages, \fBputmsg()\fR does not block when the write queue is full and \fBO_NDELAY\fR or \fBO_NONBLOCK\fR is set. Instead, it fails and sets \fBerrno\fR to \fBEAGAIN\fR. .sp .LP The \fBputmsg()\fR or \fBputpmsg()\fR function also blocks, unless prevented by lack of internal resources, waiting for the availability of message blocks in the stream, regardless of priority or whether \fBO_NDELAY\fR or \fBO_NONBLOCK\fR has been specified. No partial message is sent. .SH RETURN VALUES .sp .LP Upon successful completion, \fB0\fR is returned. Otherwise, \fB\(mi1\fR is returned and \fBerrno\fR is set to indicate the error. .SH ERRORS .sp .LP The \fBputmsg()\fR and \fBputpmsg()\fR functions will fail if: .sp .ne 2 .mk .na \fB\fBEAGAIN\fR\fR .ad .RS 16n .rt A non-priority message was specified, the \fBO_NDELAY\fR or \fBO_NONBLOCK\fR flag is set and the stream write queue is full due to internal flow control conditions. .RE .sp .ne 2 .mk .na \fB\fBEBADF\fR\fR .ad .RS 16n .rt The \fIfildes\fR argument is not a valid file descriptor open for writing. .RE .sp .ne 2 .mk .na \fB\fBEFAULT\fR\fR .ad .RS 16n .rt The \fIctlptr\fR or \fIdataptr\fR argument points to an illegal address. .RE .sp .ne 2 .mk .na \fB\fBEINTR\fR\fR .ad .RS 16n .rt A signal was caught during the execution of the \fBputmsg()\fR function. .RE .sp .ne 2 .mk .na \fB\fBEINVAL\fR\fR .ad .RS 16n .rt An undefined value was specified in \fIflags\fR; \fIflags\fR is set to \fBRS_HIPRI\fR and no control part was supplied; or the stream referenced by \fIfildes\fR is linked below a multiplexor. .RE .sp .ne 2 .mk .na \fB\fBENOSR\fR\fR .ad .RS 16n .rt Buffers could not be allocated for the message that was to be created due to insufficient streams memory resources. .RE .sp .ne 2 .mk .na \fB\fBENOSTR\fR\fR .ad .RS 16n .rt The \fIfildes\fR argument is not associated with a stream. .RE .sp .ne 2 .mk .na \fB\fBENXIO\fR\fR .ad .RS 16n .rt A hangup condition was generated downstream for the specified stream, or the other end of the pipe is closed. .RE .sp .ne 2 .mk .na \fB\fBEPIPE\fR or \fBEIO\fR\fR .ad .RS 16n .rt The \fIfildes\fR argument refers to a streams-based pipe and the other end of the pipe is closed. A \fBSIGPIPE\fR signal is generated for the calling thread. This error condition occurs only with SUS-conforming applications. See \fBstandards\fR(5). .RE .sp .ne 2 .mk .na \fB\fBERANGE\fR\fR .ad .RS 16n .rt The size of the data part of the message does not fall within the range specified by the maximum and minimum packet sizes of the topmost stream module. This value is also returned if the control part of the message is larger than the maximum configured size of the control part of a message, or if the data part of a message is larger than the maximum configured size of the data part of a message. .RE .sp .LP In addition, \fBputmsg()\fR and \fBputpmsg()\fR will fail if the stream head had processed an asynchronous error before the call. In this case, the value of \fBerrno\fR does not reflect the result of \fBputmsg()\fR or \fBputpmsg()\fR but reflects the prior error. .sp .LP The \fBputpmsg()\fR function will fail if: .sp .ne 2 .mk .na \fB\fBEINVAL\fR\fR .ad .RS 10n .rt The \fIflags\fR argument is set to \fBMSG_HIPRI\fR and \fIband\fR is non-zero. .RE .SH ATTRIBUTES .sp .LP See \fBattributes\fR(5) for descriptions of the following attributes: .sp .sp .TS tab() box; cw(2.75i) |cw(2.75i) lw(2.75i) |lw(2.75i) . ATTRIBUTE TYPEATTRIBUTE VALUE _ Interface StabilityStandard .TE .SH SEE ALSO .sp .LP \fBIntro\fR(2), \fBgetmsg\fR(2), \fBpoll\fR(2), \fBread\fR(2), \fBwrite\fR(2), \fBattributes\fR(5), \fBstandards\fR(5) .sp .LP \fISTREAMS Programming Guide\fR