Patch 3

README.md

@@ -21,12 +21,124 @@ Execute the C Program for the desired output.
 # PROGRAM:
 
 ## Write a C program that illustrates two processes communicating using shared memory.
+~~~
+//sem.c
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <sys/shm.h>
+#include <sys/types.h>
+#include <sys/wait.h>
+
+#define TEXT_SZ 2048  // Shared memory size
+
+struct shared_use_st {
+    int written;  
+    char some_text[TEXT_SZ];
+};
+
+int main() {
+    int shmid;
+    void *shared_memory = (void *)0;
+    struct shared_use_st *shared_stuff;
+
+    // Create shared memory
+    shmid = shmget((key_t)1234, sizeof(struct shared_use_st), 0666 | IPC_CREAT);
+    if (shmid == -1) {
+        fprintf(stderr, "shmget failed\n");
+        exit(EXIT_FAILURE);
+    }
+
+    // Print the shared memory ID in a predictable format
+    printf("Shared memory id = %d\n", shmid);
+
+    // Attach to shared memory
+    shared_memory = shmat(shmid, (void *)0, 0);
+    if (shared_memory == (void *)-1) {
+        fprintf(stderr, "shmat failed\n");
+        exit(EXIT_FAILURE);
+    }
+    printf("Memory attached at %p\n", shared_memory);
+
+    shared_stuff = (struct shared_use_st *)shared_memory;
+    shared_stuff->written = 0;
+
+    pid_t pid = fork();
+
+    if (pid < 0) {
+        fprintf(stderr, "Fork failed\n");
+        exit(EXIT_FAILURE);
+    }
+
+    if (pid == 0) {  // Child process (Consumer)
+        while (1) {
+            while (shared_stuff->written == 0) {
+                sleep(1); // Wait for producer
+            }
+
+            printf("Consumer received: %s", shared_stuff->some_text);
+
+            if (strncmp(shared_stuff->some_text, "end", 3) == 0) {
+                break;
+            }
+
+            shared_stuff->written = 0; // Reset for producer
+        }
+
+        // Detach shared memory
+        if (shmdt(shared_memory) == -1) {
+            fprintf(stderr, "shmdt failed\n");
+            exit(EXIT_FAILURE);
+        }
+        exit(EXIT_SUCCESS);
+    } else {  // Parent process (Producer)
+        char buffer[TEXT_SZ];
+
+        while (1) {
+            printf("Enter Some Text: ");
+            fgets(buffer, TEXT_SZ, stdin);
+
+            strncpy(shared_stuff->some_text, buffer, TEXT_SZ);
+            shared_stuff->written = 1;
+            printf(shared_stuff->some_text);
+
+            if (strncmp(buffer, "end", 3) == 0) {
+                break;
+            }
+
+            while (shared_stuff->written == 1) {
+                sleep(1); // Wait for consumer
+            }
+        }
+
+        // Wait for child process (consumer) to finish
+        wait(NULL);
+
+        // Detach and remove shared memory
+        if (shmdt(shared_memory) == -1) {
+            fprintf(stderr, "shmdt failed\n");
+            exit(EXIT_FAILURE);
+        }
+
+        if (shmctl(shmid, IPC_RMID, 0) == -1) {
+            fprintf(stderr, "shmctl failed\n");
+            exit(EXIT_FAILURE);
+        }
+
+        exit(EXIT_SUCCESS);
+    }
+}
+
+~~~
 
 
 
 
 
 ## OUTPUT
+![IMG-20260216-WA0001](https://github.com/user-attachments/assets/ee0cd6ac-6dc0-4efb-8a24-ab066f393e97)
+![IMG-20260216-WA0002](https://github.com/user-attachments/assets/291dadd6-ae1c-473d-a5f5-ae2b2118e658)
 
 
 # RESULT: