Barbara Hunter

ex1/ex1.c

@@ -9,6 +9,27 @@
 int main(void)
 {
     // Your code here
+    int x = 100;
+    printf("Hello there, before we call fork(), this is our processID is: (pid: %d) \n", (int)getpid());
+    printf("This is the parents value for x: %d \n", x);
+    int rc = fork();
+
+    if (rc < 0)
+    {
+        printf(stderr, "Forking failed \n");
+    }
+    else if (rc == 0)
+    {
+
+        printf("Hello there, if rc==0, this is our child processID is: (pid: %d) \n", (int)getpid());
+        printf("This is the childs value for x if rc==0: %d \n", x);
+    }
+    else
+    {
+        int x = 200;
+        printf("hello, if rc > 0, this is parent here (pid: %d) of child %d\n", (int)getpid(), rc);
+        printf("This is the childs value for x if rc > 0: %d \n", x);
+    }
 
     return 0;
-}
+}

ex2/ex2.c

@@ -5,10 +5,72 @@
 #include <stdio.h>
 #include <unistd.h>
 #include <stdlib.h>
+#include <sys/wait.h>
 
 int main(void)
 {
     // Your code here 
+    FILE *file;
+    printf("Hello there, before we call fork(), this is our processID is: (pid: %d) \n", (int)getpid());
+    file = fopen("text.txt", "a+");
+    while (1)
+    {
+        int c = fgetc(file);
+        if (feof(file))
+        {
+            break;
+        }
+        printf("%c", c);
+    }
+
+    int rc = fork();
+
+    if (rc < 0)
+    {
+        printf(stderr, "\nForking failed \n");
+        exit(1);
+    }
+    else if (rc == 0)
+    {
+        printf("\nWe are now attempting to wait for child process to finish. . . \n");
+        file = fopen("text.txt", "a+");
+        printf("\nHello there, if rc==0, this is our child processID is: (pid: %d) \n", (int)getpid());
+        // printf("This is the childs value for file (opening a file): %d \n", file);
+        file = fopen("text.txt", "a+");
+        fprintf(file, "%s %s %s %s %s %s %s", "\nWe", "are", "writing", "in", "the", "child", "process\n");
+        fclose(file);
+        file = fopen("text.txt", "a+");
+        while (1)
+        {
+            int c = fgetc(file);
+            if (feof(file))
+            {
+                break;
+            }
+            printf("%c", c);
+        }
+        fclose(file);
+    }
+    else
+    {
+        // int wc = waitpid(rc, NULL, 0);
+        printf("\nOur child has now finished executing, we are back in Parent process with PID: (%d)\n", (int)getpid());
+        file = fopen("text.txt", "a+");
+        fprintf(file, "%s %s %s %s %s %s %s", "\nWe", "are", "writing", "after", "the", "child", "process\n");
+        fclose(file);
+        // printf("This is the childs value for file (opening a file): %d \n", file);
+        file = fopen("text.txt", "a+");
+        while (1)
+        {
+            int c = fgetc(file);
+            if (feof(file))
+            {
+                break;
+            }
+            printf("%c", c);
+        }
+        fclose(file);
+    }
 
     return 0;
 }

ex2/text.txt

@@ -0,0 +1,4 @@
+
+We are writing after the child process
+
+We are writing in the child process

ex3/ex3.c

@@ -10,6 +10,24 @@
 int main(void)
 {
     // Your code here
+    int rc = fork();
+
+    if (rc < 0)
+    {
+        printf(stderr, "Forking failed \n");
+    }
+    else if (rc == 0)
+    {
+
+        printf("Hello there, if rc==0, this is our child processID is: (pid: %d) \n", (int)getpid());
+        printf("Goodbye\n");
+    }
+    else
+    {
+        int wc = waitpid(rc, NULL, 0);
+        printf("Hello there, if rc==0, this is our Parent processID is: (pid: %d) \n", (int)getpid());
+        printf("Hello\n");
+    }
 
     return 0;
-}
+}

ex4/ex4.c

@@ -10,7 +10,22 @@
 
 int main(void)
 {
-    // Your code here    
+    // Your code here   
+    int status;
+    // 2 strings, one is /bin/ls and the other is to finish with a NULL
+    char *args[2];
+
+    args[0] = "/bin/ls";
+    args[1] = NULL;
+    int y = fork(); 
+
+    if (y == 0) {
+    execv(args[0], args);
+
+  } else {
+
+    wait(&status);
+  }
 
     return 0;
 }