555*DBMS_PIPE.RECEIVE_MESSAGE(CHR(99)||CHR(99)||CHR(99),15)

This is an Oracle PL/SQL call using the DBMS_PIPE package for inter-session communication.

What it does

• CHR(99) is the character 'c'. CHR(99)||CHR(99)||CHR(99) builds the string 'ccc'.
• DBMS_PIPE.RECEIVE_MESSAGE('ccc', 15) tries to receive one message from the pipe named "ccc".
• The second argument, 15, is the timeout in seconds. The call will wait up to 15 seconds for a message to arrive.
• The function returns the message content as a string. If no message arrives within the timeout, it returns NULL (or an empty result, depending on your environment).

If you want to see it in a small block:

• Example (assuming a message will be sent to pipe 'ccc' by another session):

declare l_msg varchar2(32767); begin l_msg := DBMS_PIPE.RECEIVE_MESSAGE(CHR(99)||CHR(99)||CHR(99), 15); if l_msg is null then dbms_output.put_line('No message within 15 seconds.'); else dbms_output.put_line('Received: ' || l_msg); end if; end; /

Notes

• The pipe must exist and be used consistently by the sending side (DBMS_PIPE.SEND_MESSAGE) and receiving side.
• This call blocks up to 15 seconds; if a message arrives earlier, it returns immediately with the message.
• DBMS_PIPE is Oracle-specific and primarily used for simple inter-session communication. It’s not suitable for high-throughput or cross-instance messaging without careful design.

If you want, I can show how to send a message to the same pipe and run a full send/receive example.