codefirst-dockerproxy/lib/gclp/examples/Basic_Example

This directory contains a very basic example of usage of the generic 

package.  



Our goal

========



We want to write the line parsing code for a program that is supposed

to contact a remote host, authenticating with a username and,

possibly, a password.  By default the remote host listens on port

4242, but a different port can be specified.  The main procedure in

basic_example-main.adb implements the required command line parsing

and prints the result on the standard output.



More precisely, the parameters on the command line are to be specified

as follows



  * The host address will be specified with the parameter "host" (only

    numerical addresses are accepted)



  * The optional port will be specified with the parameter "port", if

    not specified, the port defaults to 4242



  * The username can be specified, equivalently, with the parameter

    "user" or with the parameter "username"

 

  * The optional password can be specified, equivalently, with the parameter

    "pwd" or with the parameter "password". If not specified, the

     password defaults to ""



Examples

--------



Therefore, for example, the following command lines are accepted



  basic_example-main host=196.18.1.34  user=pippo



    Contact host 196.18.1.34 on port 4242 with username pippo and no password



  basic_example-main host=196.18.1.34  username=pippo



    Equivalent to the command line above



  basic_example-main host=196.18.1.34  user=pippo pwd=pluto



    Contact host 196.18.1.34 with username pippo and password pluto



  basic_example-main host=196.18.1.34  user=pippo password=pluto



    Equivalent to the command line above



  basic_example-main host=196.18.1.34 port=12345  user=pippo



    Contact host 196.18.1.34 on port 12345 with username pippo and no password





Structure of the program

========================



It is very simple:



  * basic_example-main.adb  



      Contains the main procedure



  * basic_example-parameters.adb 



      Defines a record that holds the four parameters (host, port,

      username and password) that can be specified by the user.  It

      defines also procedures that set the four parameters and that

      can be used as callbacks for the line parsers.