error message on cmd segfault.

tests/test_segfault.c

@@ -0,0 +1,17 @@
+
+# include <stdio.h>
+ #include <unistd.h>
+
+int	main(int argc, char *argv[], char *envp[])
+{
+	int i;
+	char	*str;
+
+	str = NULL;
+	i = 0;
+	while (str[i])
+	{
+		write(1, &str[i], 1);
+	}
+	return (0);
+}