freepascal.compiler/packages/fcl-web/examples/echo

Responds with the calling and system parameters, example
================================================
Demonstrates how to create a basic fpweb application. It responds to a request
with a list of received/sent parameters, server settings and variables.

Note, that other than the main project file (echo.lpr) there is not much that
needs to change with using fpweb, no matter if we create CGI/FCGI applications
or Apache modules. The web server config is different for each, of course.

=====================
1. Compiling
1.a; with FPC
1.b; with Lazarus
2. Setup
2.a; as CGI
2.b; as Apache module
2.c; as FCGI
=====================

1. Compiling:
-------------
We can either use FPC directly, or Lazarus to compile the CGI/FCGI/Apache
module application. The main project .lpr file, as well as the Lazarus .lpi is
in the cgi/fcgi/apache directories.

1.a; with FPC
-------------
Enter to the directory (cgi/fcgi/apache) that has the .lpr file you wish to
compile, and then execute the command

fpc -Fu../webmodule echo.lpr

The -Fu parameter shows FPC where to find the web module source code. All
three web applications share the same web module code.

1.b; with Lazarus
-----------------
It needs the WebLaz Package installed. Open the .lpi file from the choosen
application directory (cgi/fcgi/apache), and then

Run -> Build from the menu.


2. Setup:
---------

2.a; as CGI
-----------
http:///cgi-bin// should start the example if
everything is set up properly.
ex: http://127.0.0.1:8080/cgi-bin/echo.exe/

Note: You need to change the CGI application name if needed (for example, on
Linux it is not echo.exe).
Also, if your server is listening on port 80 instead of 8080, you can leave
the :8080 part from the calling URL.


2.b; as Apache module
---------------------
http://// should start the example if
everything is set up properly.
ex: http://127.0.0.1:8080/myapache/

if in the Apache configuration file (ex: httpd.conf) it was set up as:

LoadModule mod_echo "/echo.dll"

SetHandler mod_echo
Order allow,deny
Allow from all


Note: You need to change the module name if needed. For example on Linux,
the module can be libecho.so or just simply libecho and not echo.dll .

Note: If you recompile an Apache module while the module itself is loaded into
the Apache server, the compilation will fail, because the file is in use
(Apache modules stay in the memory). So first, you always need to stop the
Apache server before you recompile or before you copy over the new version of
the created module.


2.c; as FCGI
------------
http://// should start the example if
everything is set up properly.
ex: http://127.0.0.1:8080/myfcgi/
if in the Apache configuration file (ex: httpd.conf) it was set up as:

LoadModule fastcgi_module "/mod_fastcgi-2.4.6-AP22.dll"

">
# Options +ExecCGI <- not needed if ScriptAlias is used below
Order allow,deny
Allow from all

#External FCGI app, has to start manually, Apache will not do it
FastCgiExternalServer "/echo.exe" -host 127.0.0.1:2015 -idle-timeout 30 -flush
#optionally, to shorten the calling URL and to not display the executable file name (if used, no +ExecCGI is needed above)
ScriptAlias /myfcgi "/echo.exe"


Note: You need to change the module name if needed. For example on Linux,
the module is not mod_fastcgi-2.4.6-AP22.dll but mod_fastcgi.so (need to be
compiled from sources found at http://www.fastcgi.com/dist/ ).
The port (2015 in this example) must match the one set in the project main
file (echo.lpr).
The FCGI application must be running in order for this demo to work (external
FCGI server setup). Do not forget to restart it after changes and
recompilation.
Also, mod_fastcgi is not the same as mod_fcgid that the Apache project is
developing. The latter does not support external FCGI server apps.
There are other ways than external FCGI server apps to handle the FCGI
protocol and both mod_fastcgi and mod_fcgid supports that. However, external
FCGI servers are the best for debugging and development, that is why the
examples do it that way.