The following C++ code is from a lab from my class and there is a lot that if unfamiliar to me, can someone please write notes near the lines explaining what each line does.

//msg1.cpp /* Here's the receiver program. */ #include  #include  #include  #include  #include  #include  #include  #include  struct my_msg_st { long int my_msg_type; char some_text[BUFSIZ]; }; int main() { int running = 1; int msgid; struct my_msg_st some_data; long int msg_to_receive = 0; /* First, we set up the message queue. */ msgid = msgget((key_t)1234, 0666 | IPC_CREAT); if (msgid == -1) { fprintf(stderr, "msgget failed with error: %d ", errno); exit(EXIT_FAILURE); } /* Then the messages are retrieved from the queue, until an end message is encountered. Lastly, the message queue is deleted. */ while(running) { if (msgrcv(msgid, (void *)&some_data, BUFSIZ, msg_to_receive, 0) == -1) { fprintf(stderr, "msgrcv failed with error: %d ", errno); exit(EXIT_FAILURE); } printf("You wrote: %s", some_data.some_text); if (strncmp(some_data.some_text, "end", 3) == 0) { running = 0; } } if (msgctl(msgid, IPC_RMID, 0) == -1) { fprintf(stderr, "msgctl(IPC_RMID) failed "); exit(EXIT_FAILURE); } exit(EXIT_SUCCESS); } 

//msg2.cpp /* The sender program is very similar to msg1.cpp. In the main set up, delete the msg_to_receive declaration and replace it with buffer[BUFSIZ], remove the message queue delete and make the following changes to the running loop. We now have a call to msgsnd to send the entered text to the queue. */ #include  #include  #include  #include  #include  #include  #include  #include  #define MAX_TEXT 512 struct my_msg_st { long int my_msg_type; char some_text[MAX_TEXT]; }; int main() { int running = 1; struct my_msg_st some_data; int msgid; char buffer[BUFSIZ]; msgid = msgget((key_t)1234, 0666 | IPC_CREAT); if (msgid == -1) { fprintf(stderr, "msgget failed with error: %d ", errno); exit(EXIT_FAILURE); } while(running) { printf("Enter some text: "); fgets(buffer, BUFSIZ, stdin); some_data.my_msg_type = 1; strcpy(some_data.some_text, buffer); if (msgsnd(msgid, (void *)&some_data, MAX_TEXT, 0) == -1) { fprintf(stderr, "msgsnd failed "); exit(EXIT_FAILURE); } if (strncmp(buffer, "end", 3) == 0) { running = 0; } } exit(EXIT_SUCCESS); }