Metrologic Optimus R, Programming Manual

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166 "C" Programming Guide For Optimus S/R
Description This function sets non-blocking operation back to blocking operation.
Blocking operation is the default behavior for network functions. When in
blocking operation, calls to network functions will run to completion, or return
a timeout error if an associated time limit is run out.
Return If successful, it returns 0.
On error, it returns a negative value. (?)
See Also socket_noblock
socket_cansend
Purpose To check if data can be sent.
Syntax int socket_cansend (int conno, unsigned int len);
int conno; /* connection number */
unsigned int len; /* number of bytes to write */
Example if (socket_cansend (conno, strlen (buf)))
Nwrite (conno, buf, strlen (buf));
Description
This function checks if the amount of data (byte count) specified by
len
can be
written out immediately to the connection specified conno .
Return If okay, it returns a non-zero value.
Otherwise, it returns 0.
See Also
Nwrite
socket_fin
Purpose To set the FIN flag on the next outgoing TCP segment.
Syntax int socket_fin (int conno);
int conno; /* connection number */
Example
val = socket_fin (conno);
Description The next TCP segment to be written, following a call to this function, will have
the FIN flag set in the TCP header. This is useful for shutting down a
connection at the same time that the last segment is sent. After that, call
Nclose() to finish closing the connection. Note that Nclose() will not send a
FIN segment in this case.
Return If successful, it returns 0.
Otherwise, it returns -1.
See Also Nclose