Process init commit

ex1/ex1.c

@@ -9,6 +9,23 @@
 int main(void)
 {
     // Your code here
+    int x = 100;
+    int my_fork = fork();
+
+    if (my_fork == 0) {
+        printf("x child is %d\n", x);
+        x = 111;
+        printf("x child is now %d\n", x);
+    }
+    if (my_fork > 0 ) {
+        printf("x parent is %d\n", x);
+        x = 222;
+        printf("x parent is now %d\n", x);
+    }
+    if (my_fork < 0) {
+        printf("Error!");
+    }
+
 
     return 0;
 }

ex2/ex2.c

@@ -8,7 +8,21 @@
 
 int main(void)
 {
-    // Your code here 
-
+    // Your code here
+    int x = 100;
+    FILE * fp;
+    fp = fopen("text.txt", "w");
+    int my_fork = fork();
+    if (my_fork == 0) {
+        fprintf(fp, "%s", "Child\n");
+        printf("Child\n");
+        fclose(fp);
+    }
+    else if (my_fork > 0) {
+        fprintf(fp, "%s", "Parent\n");
+        printf("Parent\n");
+        fclose(fp);
+    }
+
     return 0;
 }

ex2/text.txt

@@ -0,0 +1,2 @@
+Parent
+Child

ex3/ex3.c

@@ -11,5 +11,19 @@ int main(void)
 {
     // Your code here
 
+    int my_fork = fork();
+    if(my_fork == 0) {
+        printf("hello\n");
+
+    }
+    else if(my_fork > 0 ) {
+        wait(NULL);
+        printf("goodbye\n");
+
+    } else {
+        printf("Error!");
+        exit(1);
+    }
+
     return 0;
 }

ex4/ex4.c

@@ -10,7 +10,18 @@
 
 int main(void)
 {
-    // Your code here    
+    // Your code here
+    pid_t pid;
+    pid = fork();    
+    if (pid < 0) {
+        printf("Error %u\n", getpid());
+    } else if (pid == 0) {
+        printf("Child, pid = %u\n", getpid());
+        char *args[] = {"/bin/ls", NULL};
+        execv(args[0], args);
+    } else {
+        printf("Parent, pid = %u\n", getpid());
+    }
 
     return 0;
 }

ex5/ex5.c

@@ -16,7 +16,22 @@ char* msg3 = "hello world #3";
 
 int main(void)
 {
-    // Your code here
-
+    char inbuf [MSGSIZE]; // buffer that will hold incoming data being written
+    int p[2]; // two element array to hold and read write file descriptors
+
+    if (pipe(p) < 0) {
+        fprintf(stderr, "pipe failed\n");
+        exit(1);
+    }
+
+    write(p[1], msg1, MSGSIZE);
+    write(p[1], msg2, MSGSIZE);
+    write(p[1], msg3, MSGSIZE);
+
+    for (int i = 0; i<3; i++){
+        //read 16 bytes of data from file descriptor
+        read(p[0], inbuf, MSGSIZE);
+        printf("%s\n", inbuf);
+    }
     return 0;
 }

ex6/ex6.c

@@ -21,6 +21,16 @@ and `clock_gettime()` should work just fine.
 int main()
 {
     // Your code here
-
+    int diff;
+	struct timespec start, end;
+	int i;
+    clock_gettime(CLOCK_MONOTONIC, &start);
+    for (i = 0; i < number_iter; i++)
+    {
+        write(fileno(stdout), NULL, 0);
+    }
+    clock_gettime(CLOCK_MONOTONIC, &end);
+    diff = (BILLION * (end.tv_sec - start.tv_sec) + end.tv_nsec - start.tv_nsec) / number_iter;
+    printf("elapsed time = %llu nanoseconds\n", (long long unsigned int)diff);
     return 0;
 }