available Function

This function determines the number of bytes available for reading from a TCP/IP connection. It is the number of bytes that can be read immediately without blocking. Determines if data is ready to be read from the connection.

Syntax

UTL_TCP.AVAILABLE (

c        IN OUT NOCOPY connection, 
timeout  IN PLS_INTEGER DEFAULT 0)

RETURN PLS_INTEGER;

Parameters

Table 83-5 available Function Parameters

Parameter	Description
c (IN OUT NOCOPY)	The TCP connection to determine the amount of data that is available to be read from.
timeout	A time in seconds to wait before giving up and reporting that no data is available. Zero (0) indicates not to wait at all. NULL indicates to wait forever.

Usage Notes

The connection must have already been opened via a call to open_connection(). Users may use this API to determine if data is available to be read before calling the read API so that the program will not be blocked because data is not ready to be read from the input.

The number of bytes available for reading returned by this function may less than than what is actually available. On some platforms, this function may only return 1, to indicate that some data is available. If you are concerned about the portability of your application, assume that this function returns a positive value when data is available for reading, and 0 when no data is available. The following example illustrates using this function in a portable manner:

DECLARE
   c   utl_tcp.connection
   data VARCHAR2(256);
   len  PLS_INTEGER;
BEGIN
   c := utl_tcp.open_connection(...);
   LOOP
      IF (utl_tcp.available(c) > 0) THEN
         len := utl_tcp.read_text(c, data, 256);
      ELSE
         ---do some other things
        . . . .
      END IF
   END LOOP;
END;

Related Functions

read_raw(), read_text(), read_line()