.TH qlibs: socket_send 3
.SH ROUTINES
socket_send \- sending data over a UDP socket
.SH SYNTAX
.B #include \(dqsocket_if.h\(dq

int \fBsocket_send4\fP(int \fIs\fR,const char *\fIbuf\fR,unsigned int \fIlen\fR,
                     const char \fIip\fR[4],uint16 \fIport\fR);
.br
int \fBsocket_send6\fP(int \fIs\fR,const char *\fIbuf\fR,unsigned int \fIlen\fR,
                     const char \fIip\fR[16],uint16 \fIport\fR,uint32 \fIscope_id\fR);
.br
int \fBsocket_send\fP(int \fIs\fR,const char *\fIbuf\fR,unsigned int \fIlen\fR,
                    const char \fIip\fR[16],uint16 \fIport\fR,uint32 \fIscope_id\fR);
.SH DESCRIPTION
.B socket_send4 
sends \fIlen\fR bytes starting at \fIbuf\fR in a UDP
datagram over the socket \fIs\fR to UDP port \fIport\fR on IPv4 address
\fIip\fR.

.B socket_send6 
sends \fIlen\fR bytes starting at \fIbuf\fR in a UDP datagram 
over the socket \fIs\fR to UDP port \fIport\fR on IPv6 address \fIip\fR and perhaps 
using \fIscope_id\fR as outging interface.

For link-local IPv6 (LLU) addresses \fIscope_id\fR specifies the outgoing
interface index. 
.I socket_id 
can be queried for the given name of the interface (e.g. "eth0") by means of
.BR socket_getifidx .  
\fIscope_id\fR should normally be set to 0 except for link local IPv6 addresses

.B socket_send
sends \fIlen\fR bytes starting at \fIbuf\fR in a UDP datagram
over the socket \fIs\fR to UDP port \fIport\fR on IP address \fIip\fR and perhaps
using \fIscope_id\fR as outging interface.

You can call 
.B socket_send* 
without calling 
.BR socket_bind* .  
This has the effect as first calling 
.B socket_bind4
with IP address 0.0.0.0 and port 0
or 
.B socket_bind6
with IP address :: and port 0.
.SH RETURN VALUE
.B socket_send* 
returns 
.I 0 
if the datagram was sent successfully.  If not,
it returns 
.I -1 
and sets 
.I errno 
appropriately.
.SH EXAMPLE
  #include <socket_if.h>

  int \fIs\fR;
  char \fIip\fR[4];
  uint16 \fIp\fR;

  s = socket_udp();
  socket_bind(s,ip,p);
  socket_send(s,"hello, world",12,ip,p,0);
.SH "SEE ALSO"
socket_if(3), 
socket_info(3), 
socket_bind(3), 
socket_connect(3),
socket_recv(3), 
socket_setup(3), 
socket_tcp(3), 
socket_udp(3)