void func(char *s1, char *s2) {
  char d[32];
  strncpy(d,s1,sizeof d - 1);
  strncat(d,s2,sizeof d - 1);
  ...
}

int main(int argc, char* argv[]) {
  char d[32];
  if (argc==2) 
    strcpy(d,argv[1]);

  ...
  return 0;
}

byte[] GetKey(UInt32 keySize) {
  byte[] key = null;

  try {
    key = new byte[keySize];
    RNGCryptoServiceProvider.Create().GetBytes(key);
  }
  catch (Exception e) {
    Random r = new Random();
    r.NextBytes(key);
  }

  return key;
}

void func(const char *s) {
  if (!s) return;
  char t[3];
  memcpy(t,s,3);
  t[3] = 0;
  ...
}

void func(const char *s, int i) {
  if (!s) return;
  char t[3];
  memcpy(t,s,3);
  t[i] = 0;
  ...
}

public class Barrel {
  // By default, a barrel contains one rhesus monkey.  
  private static Monkey[] defaultMonkeys = 
    new[] { new RhesusMonkey() };
  // backing store for property.
  private IEnumerable<Monkey> monkeys = null; 

  public IEnumerable<Monkey> Monkeys {
    get {
      if (monkeys == null) {
        if (MonkeysReady())
          monkeys = PopulateMonkeys();
        else
          monkeys = defaultMonkeys;
      }
      return monkeys;
    }
  }
}

protected void Page_Load(object sender, EventArgs e) {
  string lastLogin = Request["LastLogin"];
  if (String.IsNullOrEmpty(lastLogin)) {
    HttpCookie lastLoginCookie = new HttpCookie("LastLogin",
      DateTime.Now.ToShortDateString());
    lastLoginCookie.Expires = DateTime.Now.AddYears(1);
    Response.Cookies.Add(lastLoginCookie);
  }
  else {
    Response.Write("Welcome back! You last logged in on " + lastLogin);
    Response.Cookies["LastLogin"].Value = 
      DateTime.Now.ToShortDateString();
  }
}

private decimal? lookupPrice(XmlDocument doc) {
  XmlNode node = doc.SelectSingleNode(
    @"//products/product[id/text()='" + 
    Request["itemId"] + "']/price");
  if (node == null)
    return null;
  else
    return (Convert.ToDecimal(node.InnerText));
}

public class CustomSessionIDManager : System.Web.Session    State.SessionIDManager
{
    private static object lockObject = new object();

    public override string CreateSessionID(HttpContext context)
    {
        lock (lockObject)
        {
            Int32? lastSessionId = (int?)context.Application                ["LastSessionId"];
            if (lastSessionId == null)
                lastSessionId = 1;
            else
                lastSessionId++;
            context.Application["LastSessionId"] = lastSessionId;
            return lastSessionId.ToString();
        }
    }
}

bool login(string username, 
           string password, 
           SqlConnection connection, 
           out string errorMessage) {
  SqlCommand selectUserAndPassword = new SqlCommand(
    "SELECT Password FROM UserAccount WHERE Username = @username",
    connection);
  selectUserAndPassword.Parameters.Add(
    new SqlParameter("@username",  username));
  string validPassword = 
    (string)selectUserAndPassword.ExecuteScalar();

  if (validPassword == null) {
    // the user doesn't exist in the database
    errorMessage = "Invalid user name";
    return false;
  }
  else if (validPassword != password) {
    // the given password doesn't match 
    errorMessage = "Incorrect password";
    return false;
  }
  else {
    // success
    errorMessage = String.Empty;
    return true;
  }
}

bool verifyCode(string discountCode) {
  // We store the hash of the secret code instead of 
  // the plaintext of the secret code.
  // Hash the incoming value and compare it against 
  // the stored hash.
  SHA1Managed hashFunction = new SHA1Managed();
  byte[] codeHash = 
    hashFunction.ComputeHash(
      System.Text.Encoding.Unicode.GetBytes(discountCode));
  byte[] secretCode = new byte[] { 
    116, 46, 130, 122, 36, 234, 158, 125, 163, 122,
    157, 186, 64, 142, 51, 153, 113, 79, 1, 42 };

  if (codeHash.Length != secretCode.Length) {
    // The hash lengths don't match, so the strings don't
    // match this should never happen, but we check anyway
    return false;
  }

  // perform an element-by-element comparison of the arrays
  for (int i = 0; i < codeHash.Length; i++) {
    if (codeHash[i] != secretCode[i])
      return false; // the hashes don't match
  }

  // all the elements match, so the strings match
  // the discount code is valid, inform the server
  WebServiceSoapClient client = new WebServiceSoapClient();
  client.ApplyDiscountCode();

  return true;
}