feat: update structure

cs2106/lectures/l5/2.c

@@ -0,0 +1,26 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <sys/shm.h>
+
+int main() {
+    int shmid, input, *shm;
+  printf("Shared memory id: ");
+  scanf("%d", &shmid);
+
+  shm = (int*) shmat(shmid, NULL, 0);
+  if (shm == (int*) -1) {
+    printf("Error: Cannot attach!\n");
+    exit(1);
+  }
+
+  for(int i = 0; i < 3; i++) {
+    scanf("%d", &input);
+    shm[i+1] = input;
+  }
+  shm[0] = 1;
+
+  shmdt((char*) shm);
+  return 0;
+
+}