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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 sendto 3XNET "1 Nov 2003" "SunOS 5.11" "X/Open Networking Services Library Functions" .SH NAME sendto \- send a message on a socket .SH SYNOPSIS .LP .nf \fBcc\fR [ \fIflag\fR... ] \fIfile\fR... \fB-lxnet\fR [ \fIlibrary\fR ... ] #include \fBssize_t\fR \fBsendto\fR(\fBint\fR \fIsocket\fR, \fBconst void *\fR\fImessage\fR, \fBsize_t\fR \fIlength\fR, \fBint\fR \fIflags\fR, \fBconst struct sockaddr *\fR\fIdest_addr\fR, \fBsocklen_t\fR \fIdest_len\fR); .fi .SH DESCRIPTION .sp .LP The \fBsendto()\fR function sends a message through a connection-mode or connectionless-mode socket. If the socket is connectionless-mode, the message will be sent to the address specified by \fIdest_addr\fR. If the socket is connection-mode, \fIdest_addr\fR is ignored. .sp .LP If the socket protocol supports broadcast and the specified address is a broadcast address for the socket protocol, \fBsendto()\fR will fail if the \fBSO_BROADCAST\fR option is not set for the socket. .sp .LP The \fIdest_addr\fR argument specifies the address of the target. The \fIlength\fR argument specifies the length of the message. .sp .LP Successful completion of a call to \fBsendto()\fR does not guarantee delivery of the message. A return value of \fB\(mi1\fR indicates only locally-detected errors. .sp .LP If space is not available at the sending socket to hold the message to be transmitted and the socket file descriptor does not have \fBO_NONBLOCK\fR set, \fBsendto()\fR blocks until space is available. If space is not available at the sending socket to hold the message to be transmitted and the socket file descriptor does have \fBO_NONBLOCK\fR set, \fBsendto()\fR will fail. .sp .LP The socket in use may require the process to have appropriate privileges to use the \fBsendto()\fR function. .SH PARAMETERS .sp .LP The function takes the following arguments: .sp .ne 2 .mk .na \fB\fIsocket\fR\fR .ad .RS 13n .rt Specifies the socket file descriptor. .RE .sp .ne 2 .mk .na \fB\fImessage\fR\fR .ad .RS 13n .rt Points to a buffer containing the message to be sent. .RE .sp .ne 2 .mk .na \fB\fIlength\fR\fR .ad .RS 13n .rt Specifies the size of the message in bytes. .RE .sp .ne 2 .mk .na \fB\fIflags\fR\fR .ad .RS 13n .rt Specifies the type of message transmission. Values of this argument are formed by logically OR'ing zero or more of the following flags: .sp .ne 2 .mk .na \fBMSG_EOR\fR .ad .RS 11n .rt Terminates a record (if supported by the protocol) .RE .sp .ne 2 .mk .na \fBMSG_OOB\fR .ad .RS 11n .rt Sends out-of-band data on sockets that support out-of-band data. The significance and semantics of out-of-band data are protocol-specific. .RE .RE .sp .ne 2 .mk .na \fB\fIdest_addr\fR\fR .ad .RS 13n .rt Points to a \fBsockaddr\fR structure containing the destination address. The length and format of the address depend on the address family of the socket. .RE .sp .ne 2 .mk .na \fB\fIdest_len\fR\fR .ad .RS 13n .rt Specifies the length of the \fBsockaddr\fR structure pointed to by the \fIdest_addr\fR argument. .RE .SH USAGE .sp .LP The \fBselect\fR(3C) and \fBpoll\fR(2) functions can be used to determine when it is possible to send more data. .SH RETURN VALUES .sp .LP Upon successful completion, \fBsendto()\fR returns the number of bytes sent. Otherwise, \fB-1\fR is returned and \fBerrno\fR is set to indicate the error. .SH ERRORS .sp .LP The \fBsendto()\fR function will fail if: .sp .ne 2 .mk .na \fB\fBEAFNOSUPPORT\fR\fR .ad .RS 16n .rt Addresses in the specified address family cannot be used with this socket. .RE .sp .ne 2 .mk .na \fB\fBEAGAIN\fR\fR .ad .br .na \fB\fBEWOULDBLOCK\fR\fR .ad .RS 16n .rt The socket's file descriptor is marked \fBO_NONBLOCK\fR and the requested operation would block. .RE .sp .ne 2 .mk .na \fB\fBEBADF\fR\fR .ad .RS 16n .rt The \fIsocket\fR argument is not a valid file descriptor. .RE .sp .ne 2 .mk .na \fB\fBECONNRESET\fR\fR .ad .RS 16n .rt A connection was forcibly closed by a peer. .RE .sp .ne 2 .mk .na \fB\fBEFAULT\fR\fR .ad .RS 16n .rt The \fImessage\fR or \fIdestaddr\fR parameter cannot be accessed. .RE .sp .ne 2 .mk .na \fB\fBEINTR\fR\fR .ad .RS 16n .rt A signal interrupted \fBsendto()\fR before any data was transmitted. .RE .sp .ne 2 .mk .na \fB\fBEMSGSIZE\fR\fR .ad .RS 16n .rt The message is too large to be sent all at once, as the socket requires. .RE .sp .ne 2 .mk .na \fB\fBENOTCONN\fR\fR .ad .RS 16n .rt The socket is connection-mode but is not connected. .RE .sp .ne 2 .mk .na \fB\fBENOTSOCK\fR\fR .ad .RS 16n .rt The \fIsocket\fR argument does not refer to a socket. .RE .sp .ne 2 .mk .na \fB\fBEOPNOTSUPP\fR\fR .ad .RS 16n .rt The \fIsocket\fR argument is associated with a socket that does not support one or more of the values set in \fIflags\fR. .RE .sp .ne 2 .mk .na \fB\fBEPIPE\fR\fR .ad .RS 16n .rt The socket is shut down for writing, or the socket is connection-mode and is no longer connected. In the latter case, and if the socket is of type \fBSOCK_STREAM\fR, the \fBSIGPIPE\fR signal is generated to the calling thread. .RE .sp .LP If the address family of the socket is \fBAF_UNIX\fR, then \fBsendto()\fR will fail if: .sp .ne 2 .mk .na \fB\fBEIO\fR\fR .ad .RS 16n .rt An I/O error occurred while reading from or writing to the file system. .RE .sp .ne 2 .mk .na \fB\fBELOOP\fR\fR .ad .RS 16n .rt Too many symbolic links were encountered in translating the pathname in the socket address. .RE .sp .ne 2 .mk .na \fB\fBENAMETOOLONG\fR\fR .ad .RS 16n .rt A component of a pathname exceeded \fINAME_MAX\fR characters, or an entire pathname exceeded \fIPATH_MAX\fR characters. .RE .sp .ne 2 .mk .na \fB\fBENOENT\fR\fR .ad .RS 16n .rt A component of the pathname does not name an existing file or the pathname is an empty string. .RE .sp .ne 2 .mk .na \fB\fBENOTDIR\fR\fR .ad .RS 16n .rt A component of the path prefix of the pathname in the socket address is not a directory. .RE .sp .LP The \fBsendto()\fR function may fail if: .sp .ne 2 .mk .na \fB\fBEACCES\fR\fR .ad .RS 16n .rt Search permission is denied for a component of the path prefix; or write access to the named socket is denied. .RE .sp .ne 2 .mk .na \fB\fBEDESTADDRREQ\fR\fR .ad .RS 16n .rt The socket is not connection-mode and does not have its peer address set, and no destination address was specified. .RE .sp .ne 2 .mk .na \fB\fBEHOSTUNREACH\fR\fR .ad .RS 16n .rt The destination host cannot be reached (probably because the host is down or a remote router cannot reach it). .RE .sp .ne 2 .mk .na \fB\fBEINVAL\fR\fR .ad .RS 16n .rt The \fIdest_len\fR argument is not a valid length for the address family. .RE .sp .ne 2 .mk .na \fB\fBEIO\fR\fR .ad .RS 16n .rt An I/O error occurred while reading from or writing to the file system. .RE .sp .ne 2 .mk .na \fB\fBEISCONN\fR\fR .ad .RS 16n .rt A destination address was specified and the socket is already connected. .RE .sp .ne 2 .mk .na \fB\fBENETDOWN\fR\fR .ad .RS 16n .rt The local interface used to reach the destination is down. .RE .sp .ne 2 .mk .na \fB\fBENETUNREACH\fR\fR .ad .RS 16n .rt No route to the network is present. .RE .sp .ne 2 .mk .na \fB\fBENOBUFS\fR\fR .ad .RS 16n .rt Insufficient resources were available in the system to perform the operation. .RE .sp .ne 2 .mk .na \fB\fBENOMEM\fR\fR .ad .RS 16n .rt Insufficient memory was available to fulfill the request. .RE .sp .ne 2 .mk .na \fB\fBENOSR\fR\fR .ad .RS 16n .rt There were insufficient STREAMS resources available for the operation to complete. .RE .sp .LP If the address family of the socket is \fBAF_UNIX\fR, then \fBsendto()\fR may fail if: .sp .ne 2 .mk .na \fB\fBENAMETOOLONG\fR\fR .ad .RS 16n .rt Pathname resolution of a symbolic link produced an intermediate result whose length exceeds \fIPATH_MAX\fR. .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 _ MT-LevelMT-Safe .TE .SH SEE ALSO .sp .LP \fBpoll\fR(2), \fBgetsockopt\fR(3XNET), \fBrecv\fR(3XNET), \fBrecvfrom\fR(3XNET), \fBrecvmsg\fR(3XNET), \fBselect\fR(3C), \fBsend\fR(3XNET), \fBsendmsg\fR(3XNET), \fBsetsockopt\fR(3XNET), \fBshutdown\fR(3XNET), \fBsocket\fR(3XNET), \fBattributes\fR(5), \fBstandards\fR(5)