** Start of listing of h1.cc **
#include <iostream>
#include <ctime>
#include <cstdlib>

main()
{
  time_t t;
  struct tm* ptm;
  char* sTime;
  int slen;
  char* ip;
  char* path;

  std::cout << "Content-type: text/plain\n\n";

  t = time(NULL);
  ptm = localtime(&t);
  sTime = asctime(ptm);
  slen = strlen(sTime);
  sTime[slen-1] = sTime[slen]; /* Copy null byte to clobber newline. */
  slen = strlen(sTime);
  std::cout << "The time is " << sTime << " in California.\n\n";

  ip = getenv("REMOTE_ADDR");
  std::cout << "The IP number " << ip;
  std::cout << " is where your client/browser is located.\n\n";

  path = getenv("PATH");
  std::cout << "The PATH is " << path << " currently\n";
  std::cout<<"(the only environment variable common to both CGI and login)\n";
}
** End of listing of h1.cc **

Here is the directory entry for that source file:
-rw-------  1 rem  user  746 Jun 28  2005 h1.cc
   ^ Note user execute permission *not* needed for source files.

That gets compiled to a.out, but then renamed to something.cgi
so that it will be usable by remote users via CGI:
-rwx------  1 rem  user  5780 Jun 28  2005 h1-c++.cgi
   ^ Note user execute permission needed for all CGI programs.
(because compiled C++ is native machine code run directly on machine)