Can we make a c++ code password protected?

Answer 1

Yeah why not. You can do something like this -
char pass [5];
cout <<"enter password";
for ( int I = 0 ; I < 5; I ++)
pass[I] = getch ();
if (pass = "yourp")
// then start your program
else
// display error message or exit

Answer 2

when we open a .cpp or .c file through terminal in Ubuntu, can we make terminal to ask password to open it?