Add lab 2

Assignment2/main.c

@@ -77,6 +77,12 @@ int main() {
                 printf("The total is %d\n", total);
             }
         }
+        if (strcmp(input, "exec\n")) {
+            char *args[2];
+            args[0] = "/bin/ls";
+            args[1] = NULL;
+            execv(args[0], args);
+        }
     }
 }
 

Lab2/.idea/.gitignore

@@ -0,0 +1,8 @@
+# Default ignored files
+/shelf/
+/workspace.xml
+# Editor-based HTTP Client requests
+/httpRequests/
+# Datasource local storage ignored files
+/dataSources/
+/dataSources.local.xml

Lab2/.idea/Lab2.iml

@@ -0,0 +1,2 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<module classpath="CMake" type="CPP_MODULE" version="4" />

Lab2/.idea/misc.xml

@@ -0,0 +1,4 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project version="4">
+  <component name="CMakeWorkspace" PROJECT_DIR="$PROJECT_DIR$" />
+</project>

Lab2/.idea/modules.xml

@@ -0,0 +1,8 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project version="4">
+  <component name="ProjectModuleManager">
+    <modules>
+      <module fileurl="file://$PROJECT_DIR$/.idea/Lab2.iml" filepath="$PROJECT_DIR$/.idea/Lab2.iml" />
+    </modules>
+  </component>
+</project>

Lab2/.idea/vcs.xml

@@ -0,0 +1,6 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project version="4">
+  <component name="VcsDirectoryMappings">
+    <mapping directory="$PROJECT_DIR$/.." vcs="Git" />
+  </component>
+</project>

Lab2/CMakeLists.txt

@@ -0,0 +1,6 @@
+cmake_minimum_required(VERSION 3.22)
+project(Lab2 C)
+
+set(CMAKE_C_STANDARD 99)
+
+add_executable(Lab2 main.c)

Lab2/main.c

@@ -0,0 +1,39 @@
+#include <stdio.h>
+#include <unistd.h>
+#include <stdlib.h>
+#include <wait.h>
+
+int main() {
+    printf("Parent PID: [%d]\n", getpid()); // Initial parent
+    if (fork() == 0) { // Forking child
+        printf("Child PID: [%d]\n", getpid());
+        int to_lowercase[2];
+        pipe(to_lowercase);
+        if (fork() == 0) { // Forking grandchild
+            printf("Grandchild PID: [%d]\n", getpid());
+            char output[100];
+            read(to_lowercase[0], output, 100); // Reading from pipe
+            close(to_lowercase[0]); // Closing read pipe
+            for (int i = 0; i < 100; i++) { // Converting to lowercase using ASCII
+                if (output[i] >= 'A' && output[i] <= 'Z') {
+                    output[i] += 32;
+                }
+            }
+            printf("%s", output);
+            printf("Grandchild PID: [%d]\n", getpid());
+            exit(EXIT_SUCCESS);
+        } else { // Child
+            char input[100];
+            fgets(input, 100, stdin); // Input
+            write(to_lowercase[1], input, 100); // Writing to pipe
+            close(to_lowercase[1]); // Closing write pipe
+            wait(NULL);
+            printf("Grandchild PID: [%d]\n", getpid());
+            exit(EXIT_SUCCESS);
+        }
+    } else { // Parent
+        wait(NULL);
+        printf("Parent PID: [%d]\n", getpid());
+    }
+    exit(EXIT_SUCCESS);
+}