55 void	receiver (void);
108 	 * conditions of the receiver.  in main()
120 	 * works before we create the receiver.  in main()
160 		receiver();  in main()
168 	 * Send the first message to the receiver and wait for the ACK.  in main()
182 	 * Send the second message to the receiver and wait for the ACK.  in main()
225 		errx(1, "receiver exited abnormally");  in sigchld_handler()
228 		errx(1, "receiver exited with status %d",  in sigchld_handler()
300 receiver()  in receiver()  function
306 		err(1, "receiver: msgget");  in receiver()
314 		err(1, "receiver: msgrcv 1");  in receiver()
318 		err(1, "receiver: message 1 data isn't correct");  in receiver()
323 		err(1, "receiver: msgsnd ack 1");  in receiver()
331 		err(1, "receiver: msgrcv 2");  in receiver()
335 		err(1, "receiver: message 2 data isn't correct");  in receiver()
340 		err(1, "receiver: msgsnd ack 2");  in receiver()