Use proper grammar.

main.c

@@ -6,6 +6,6 @@ int main(int argc, char **argv)
     printf("Enter your name: ");
     fgets(name, 255, stdin);
     name[strlen(name)-1] = '\0'; /* remove the newline at the end */
-    printf("Hello %s!\n", name);
+    printf("Hello, %s!\n", name);
     return 0;
 }