.TH SEND 2X 3/17/82
.UC 4.1a Provisional
.SH NAME
send \- send message from a socket
.SH SYNOPSIS
.ft B
#include <sys/socket.h>
.sp
send(s, to, msg, len)
.br
int cc, s;
.br
struct sockaddr *to;
.br
char *msg;
.br
int len;
.ft R
.SH DESCRIPTION
.I Send
is used to transmit a message to another socket from
a SOCK_DGRAM or SOCK_RAW socket.
The address of the target is given by
.I to.
The length of the message is given by
.I len.
If the message is too long to pass atomically through the
underlying protocol, then the error EMSGSIZE is returned, and
the message is not transmitted.
.PP
No indication of failure to deliver is implicit in
.I send.
Some locally detected errors may be reported to the user
through the return value from send being \-1 with the errors
being stored in the external variable
.B errno.
.PP
If no messages space is are available at the socket to hold
the message to be transmitted, then
.I send
normally blocks, unless the socket is SO_NONBLOCKING
in which case a
.I cc
of \-1 is returned with the external variable errno set to EWOULDBLOCK.
The
.IR select (2x)
call may be used to determine when it is possible to send more data.
.SH SEE ALSO
send(2x), socket(2x)
.SH BUGS
An option to provide a SIGIO signal when data is available
to be received is planned, but not yet implemented.
.PP
This call is provisional, and will exist in a slightly different form
in 4.2bsd.