Praktikum 11.1.2016: Beispielprogramme

20160111/noreturn-1.c

+#include <stdio.h>
+#include <stdlib.h>
+
+__attribute__ ((noreturn)) void fatal_error (char *msg)
+{
+  fprintf (stderr, "%s\n", msg);
+  exit (1);
+}
+
+int main (void)
+{
+  fatal_error ("error not found");
+}

20160111/random-1.c

+#include <stdio.h>
+#include <stdlib.h>
+#include <stdint.h>
+
+int main (int argc, char **argv)
+{
+  FILE *dev_random = fopen ("/dev/random", "rb");
+  if (!dev_random)
+    {
+      fprintf (stderr, "%s: cannot open /dev/random\n", argv[0]);
+      exit (1);
+    }
+  else
+    {
+      uint16_t x;
+      fread (&x, sizeof (x), 1, dev_random);
+      printf ("%d\n", x);
+      fclose (dev_random);
+    }
+  return 0;
+}