Environment Variables

// Fig. 19.8: environment.cpp // Program to display CGI environment variables. #include using std::cout; #include using std::string; #include using std::getenv; int main() { string environmentVariables[ 24 ] = { "COMSPEC", "DOCUMENT_ROOT", "GATEWAY_INTERFACE", "HTTP_ACCEPT", "HTTP_ACCEPT_ENCODING", "HTTP_ACCEPT_LANGUAGE", "HTTP_CONNECTION", "HTTP_HOST", "HTTP_USER_AGENT", "PATH", "QUERY_STRING", "REMOTE_ADDR", "REMOTE_PORT", "REQUEST_METHOD", "REQUEST_URI", "SCRIPT_FILENAME", "SCRIPT_NAME", "SERVER_ADDR", "SERVER_ADMIN", "SERVER_NAME","SERVER_PORT","SERVER_PROTOCOL", "SERVER_SIGNATURE","SERVER_SOFTWARE" }; cout << "Content-Type: text/html\n\n"; // output HTTP header // output XML declaration and DOCTYPE cout << "" << ""; // output html element and some of its contents cout << "" << "Environment Variables"; // begin outputting table cout << ""; // iterate through environment variables for ( int i = 0; i < 24; i++ ) { cout << ""; } // end for cout << "

" << environmentVariables[ i ] << "

"; // attempt to retrieve value of current environment variable char *value = getenv( environmentVariables[ i ].c_str() ); if ( value != 0 ) // environment variable exists cout << value; else cout << "Environment variable does not exist."; cout << "

"; return 0; } // end main /************************************************************************** * (C) Copyright 1992-2005 by Deitel & Associates, Inc. and * * Pearson Education, Inc. All Rights Reserved. * * * * DISCLAIMER: The authors and publisher of this book have used their * * best efforts in preparing the book. These efforts include the * * development, research, and testing of the theories and programs * * to determine their effectiveness. The authors and publisher make * * no warranty of any kind, expressed or implied, with regard to these * * programs or to the documentation contained in these books. The authors * * and publisher shall not be liable in any event for incidental or * * consequential damages in connection with, or arising out of, the * * furnishing, performance, or use of these programs. * **************************************************************************/