1 files changed, 118 insertions, 0 deletions
diff --git a/semestr-5/so/lista3/so21_lista_3/game.c b/semestr-5/so/lista3/so21_lista_3/game.c
new file mode 100644
index 0000000..87f8ef5
--- /dev/null
+++ b/semestr-5/so/lista3/so21_lista_3/game.c
@@ -0,0 +1,118 @@
+#include "csapp.h"
+#include "terminal.h"
+#include <string.h>
+#include <errno.h>
+
+#undef MAXLINE
+#define MAXLINE 120
+
+static sigjmp_buf env;
+
+static void signal_handler(int signo) {
+  siglongjmp(env, signo);
+}
+
+/* If interrupted by signal, returns signal number. Otherwise converts user
+ * provided string to number and saves it under num_p and returns zero. */
+static int readnum(int *num_p) {
+  char line[MAXLINE];
+  int n;
+  /* TODO: Something is missing here! Use Read() to get line from user. */
+  volatile static int ret_val;
+  ret_val = sigsetjmp(env, 1);
+  if (ret_val != 0) return ret_val;
+  
+  alarm(1);
+  n = Read(STDIN_FILENO, line, MAXLINE - 1);
+  
+  alarm(0);
+  line[n] = 0;
+  *num_p = atoi(line);
+  return 0;
+}
+
+static void game(void) {
+  int tty = tty_open();
+
+  int timeout = 0, num1 = 0, num2 = 0, sum;
+  int last_sig = 0;
+  int lives = 3;
+  int score = 0;
+
+  while (lives > 0) {
+    switch (last_sig) {
+      case 0:
+        timeout = 5;
+        num1 = random() % 100;
+        num2 = random() % 100;
+        printf("What is the sum of %d and %d?\n", num1, num2);
+        break;
+
+      case SIGINT:
+        printf(CHA(1) EL() "Bye bye!\n");
+        exit(EXIT_FAILURE);
+
+      case SIGALRM:
+        timeout--;
+        if (timeout < 0) {
+          last_sig = 0;
+          lives--;
+          printf(CHA(1) EL() "Answer was %d!\n", num1 + num2);
+          continue;
+        }
+        break;
+
+      default:
+        app_error("lastsig = %d not handled!\n", last_sig);
+        break;
+    }
+
+    /* Rewrite user prompt to show current number of lives and timeout. */
+    sigset_t set, oldset;
+    sigemptyset(&set);
+    sigaddset(&set, SIGINT);
+    sigaddset(&set, SIGALRM);
+    Sigprocmask(SIG_BLOCK, &set, &oldset);
+
+    int x, y;
+    tty_curpos(tty, &x, &y);
+    dprintf(STDOUT_FILENO, CHA(1) "lives: %d timeout: %d > ", lives, timeout);
+    if (last_sig == SIGALRM)
+      dprintf(STDOUT_FILENO, CHA(%d), y);
+
+    Sigprocmask(SIG_SETMASK, &oldset, NULL);
+
+    /* Read a number from user. */
+    last_sig = readnum(&sum);
+    if (last_sig)
+      continue;
+
+    /* Line contains user input (a number) terminated with '\0'. */
+    if (sum == num1 + num2) {
+      printf("Correct!\n");
+      score++;
+    } else {
+      printf("Incorrect!\n");
+      lives--;
+    }
+  }
+
+  Close(tty);
+
+  printf("Game over! Your score is %d.\n", score);
+}
+
+int main(void) {
+  /* Initialize PRNG seed. */
+  struct timeval tv;
+  gettimeofday(&tv, NULL);
+  srandom(tv.tv_usec);
+
+  /* SIGALRM is used for timeouts, SIGINT for graceful exit. */
+  Signal(SIGALRM, signal_handler);
+  Signal(SIGINT, signal_handler);
+
+  game();
+
+  return EXIT_SUCCESS;
+}