SOCKET_READ Function
Reads data from a socket connection.
Usage
nbytes = SOCKET_READ(connection, data)
Input Parameters
connection—A socket handle (usually returned by either SOCKET_ACCEPT or SOCKET_CONNECT).
Output Parameters
data—A pre-allocated byte array to read into.
Keywords
None.
Returned Value
nbytes—The number of bytes read from the socket or a negative value indicating an error.
Discussion
This function can be used in both client and server programs. If used in a client program, it retrieves data sent (using SOCKET_WRITE) from the server. If used in a server program, it retrieves data sent from the client.
Before calling SOCKET_READ, you must initialize data to be a byte array of sufficient size to hold the data sent from the client. It is up to the programmer to convert the data in the byte array into whatever form the server or client expects to process. PV‑WAVE provides several routines for converting data from one type to another, including BYTE, BYTEORDER, COMPLEX, DOUBLE, FLOAT, LONG, and STRING.
note | The SOCKET_READ Function is blocking and does not return until the byte array passed to it is full or a problem occurs with the connection. |
Example
In this example, a client program uses SOCKET_READ to retrieve a byte array sent from the server. Note that the STRING function is used to convert the byte array to a string before the data is printed.
PRO CLIENT
host = 'localhost'
port = 1500
socket = SOCKET_CONNECT(host,port)
IF socket EQ -1 OR socket EQ -2 THEN BEGIN
PRINT, 'SOCKET_CONNECT failed with return code: ', socket
RETURN
ENDIF
data = BYTARR(15)
nbytes = SOCKET_READ(socket,data)
PRINT, 'CLIENT received: ', STRING(data)
SOCKET_CLOSE, socket
END
See Also
For more detailed information on using the socket routines, see the PV‑WAVE Application Developer’s Guide.
