There are many categories of environment variables, including details of the client and the server. In the general CGI program development, the following environment variables plays an important role in data transfer. * The version number of the CGI standard interface used by the GATEWAY-INTERFACE CGI program. If the CGI1.1 used is used, the variable is represented as "CGI / 1.1" * Request-Method HTTP request method. The request method used by the CGI request is determined based on the variable value to determine whether the client transfer data is obtained through the STDIN or through environment variable Query-String. * Query-string query-string is the data after "?" In the CGI program URL. When using the IsIndex query or Form table using the GET method, client transfer data can be obtained by reading the variable. * Content-Length Content-Length indicates the number of bytes of the client transferred data. * Content-Type Content-Type indicates the data encoding type of the client transfer data. All environment variables and their values can be obtained using the -Environ (int) function; the corresponding value of the specified environment variable can be obtained using the GetENV (Constchar *) function.
