cleanup

Author: nalladev

s5/os/1.1.exitsyscall.c

@@ -0,0 +1,10 @@
+#include <stdio.h>  
+#include <stdlib.h>  
+
+int main() {
+    for (int i = 0;i <= 7;i++) {
+        if (i == 5) exit(0);
+        else printf("%d\n", i);
+    }
+    return 0;
+}

s5/os/1.2.opnclosesyscall.c

@@ -0,0 +1,17 @@
+#include <fcntl.h>
+#include <stdio.h>
+#include <unistd.h>
+
+int main() {
+    int fd = open("foo.txt", O_RDONLY | O_CREAT);
+
+    printf("fd = %d\n", fd);
+
+    if (fd == -1) printf("Error\n");
+    else printf("file opened\n");
+
+    if (close(fd) == -1) printf("Error\n");
+    else printf("file closed\n");
+    
+    return 0;
+}

s5/os/1.3.fork.c

@@ -0,0 +1,15 @@
+#include <stdio.h>
+
+int main() {
+    int x = 1;
+    int k = fork(); // Creates a new process
+
+    if (k < 0) printf("Error\n");
+    else if (k == 0) printf("Child has x = %d\n", ++x); // Child process increments x
+    else {
+        wait(1000); // Parent process waits for child process to finish
+        printf("Parent has x = %d\n", --x); // Parent process decrements x
+    }
+
+    return 0;
+}

s5/os/1.4.getpid.c

@@ -0,0 +1,11 @@
+#include <stdio.h>
+
+int main() {
+    int x = 1;
+    int pid = fork(); // Creates a new process
+
+    if (pid == 0) printf("Process id of Child = %d\n", getpid()); // Child process prints its PID
+    else printf("Process id of parent = %d\n", getppid()); // Parent process prints its parent's PID
+
+    return 0;
+}