CSOCKET-READ

This operation reads data from a socket. It blocks other calls until all the data requested is actually read, an error occurs or the read timeout expires.

If the socket is closed by the other peer before the entire buffer is filled, C$SOCKET will return the number of bytes read to that point, which will be less than the amount requested. The next time AGS-READ is called, -1 will be returned.

Syntax:

CALL "C$SOCKET" USING CSOCKET-READ                        socketHandle                        buffer                        length                        [timeout]                 GIVING return-code

Parameters:

CSOCKET-READ	Constant
socketHandle	USAGE HANDLE	Identifies the socket to be read.
buffer	PIC X(n)	Data to read from socket.
length	PIC 9(n)	Number of bytes to be read. Setting this parameter to zero allows to know how many bytes are available on the socket. If the buffer passed is smaller than the value of this parameter, or if the number of bytes available on the socket is less than the value of this parameter, an error will result. Due to this rule, buffer picture can’t be x any length.
timeout	PIC 9(n)	Optional parameter. It specifies the amount of milliseconds that C$SOCKET has to wait before returning if less data than the amount specified by length is available on the socket. When the timeout expires, buffer is set to the available data. If the parameter is omitted, then C$SOCKET waits until the number of bytes specified by length has been read.

Return code:

returnCode can be any signed numeric data item and provides additional information:

<0	Operation failed.
>0	Number of read bytes.