CS 3733 Operating Systems Classroom Activity on Sigaction

1. Log on to your Linux account.
2. Run ~srobbins/cr3733 and log your progress on this activity.
3. Make a directory called ch08.
4. Download the USP Chapter 8 tar file from here.
5. Untar the program into your ch08 directory.
6. Execute convertlinux in this directory.
7. Execute make in this directory.
8. Execute:
        blocktest 100000000.
   The parameter is 100 million.
   If you use a value that is too small, there will be little time between the messages.
   This value will give you about 4 seconds between them using our current hardware.
   You can double this value if you want more time.
9. Try pushing CTRL-C while the signal is blocked and while it is not.
10. Modify blocktest so that it catches the SIGINT signal as in Example 8.16:
    1. Copy the following code and put it above main:

             void catchctrlc(int signo) {
                char handmsg[] = "I found Ctrl-C\n";
                int msglen = sizeof(handmsg);
                write(STDERR_FILENO, handmsg, msglen);
             }
           

    2. Copy the following line with your declarations in main:
       

                struct sigaction act;
            

    3. Insert the following in blocktest.c before the for loop:

             newact.sa_handler = SIG_DFL;    /* new handler set to default */
             newact.sa_flags = 0;            /* no special options */
             if ((sigemptyset(&newact.sa_mask) == -1) ||
                 (sigaction(SIGINT, &newact, NULL) == -1))
                perror("Failed to set SIGINT to the default action");
            

11. Run the program with:
    ./blocktest 100000
12. Try to kill the program.
13. Answer the question about how you killed the program.