Metrologic Optimus R, Руководство по программированию

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158 "C" Programming Guide For Optimus S/R
send
Purpose To send data to a connected socket.
Syntax int send (SOCKET s, char *buf, int len, int flags);
s Descriptor identifying a connected socket
buf Pointer to the buffer in which data is to be sent
len Maximum number of bytes to be sent
flags MSG_OOB: process out-of-band data
MSG_DONTROUTE: bypass routing, use direct interface
Example SOCKET s;
char buf[1024];
int len, tlen;
...................
len = strlen (buf);
tlen = send (s, buf, len, 0);
if (tlen < 0) {
printf ("send fails on socket: %d", s);
...................
}
Description This routine writes outgoing data to a specified send buffer (
buf
) on a
connected socket.
The
flags
argument allows one of the following values:
MSG_OOB sends urgent data (out-of-bound data)
MSG_DONTROUTE sends data using direct interface
The application can avoid this blocking behavior by using socket_cansend() to
make sure there is data available before calling send(). (?)
The whole data may not be sent at one time. Check the return value in case the
send buffer overflows. (?)
Return If successful, it returns a non-negative integer (>=0) indicating the number of
bytes sent.
On error, it returns -1.
The global variable
errno
is set to indicate the error condition encountered.
See Also recv, sendto, socket_cansend
sendto
Purpose To send data to a connected socket.