Hello All,

I just started to use FPC in a project requiring a Webinterface. When porting the Lazarus/Win32 fpc-web examples (worked fine) to X86/Linux(Ubuntu) and Arm-Linux, I started to struggle.

Under Linux, the cgi program terminates w/o any output and w/o any errormessages. So Apache complains about premature page end.

=> Is there anything special to consider when using fcl-web under Linux?

=> The bread and butter cgi example (mini.pas) did run, but I like the concept of FCL-Web offering scalability between CGI, FastCGI, Apache Module and do not want to reinvent the wheel...

Currently I started copying the fcl-web sources to project folder and pinpointing with writelns to crosscheck what is running and what is not.

Kind Regards,

Christian Kranich

Yes.

* Do not use the crt, video or keyboard units.
* Do not attempt I/O to standard input/output/error.

Check the error log of apache.
It will contain the error output of the CGI script.

Michael.

Another tip for linux/unix. Try to run the CGI program from the command line, it should output something similar to this:

Exception at 0000000000497B3A: Exception:
No REQUEST_METHOD passed from server.

Otherwise there's an error in your code.

Leonardo M. Ramé
http://leonardorame.blogspot.com

Better yet, you can test CGI programs with the testcgiapp program that is located in the fcl-web sources. developed specially to test such things.

Michael.

Michael,

Thank you for the fast response!
and
Many thanks for the _lots_ of work you have done for the project!! (Have the Lazarus and FPC books asside, but want to use the first direct contact for a BIG thank you...)

The apache error log said
Premature end of script headers
(because the script sent absolute nothing)
If I had debug writelns in the code, it complained about misformed header format - showing the first debug output line)

Maybee I am looking on the wrong end: maybee the code is not able to load the template html files and
no template file = no output.
will crosscheck.

Kind Greetings from Vienna,

Christian

Hello Michael,
Hello Leonardo,

Thx for further suggestions:
- I did this already (starting from commandline):
In windows it came with an exception (like in leonardo's post) Under Linux it returns w/o _any_ output (not even an errormessage) At first I suggested any not compatible unit and commented them out one by one - but this wasn't the source of the issue BTW: I use the following units
SysUtils,Sockets,Classes,INIFiles,fpCGI(added, not sure if necessary), httpdefs,fpHTTP,fpWeb

- I will tryout the cgi testenviroment. Thx for advice, Michael

Kind Regards,

Christian

If I had debug writelns in the code, it complained about misformed

header format - showing the first debug output line)

michael said:
* Do not attempt I/O to standard input/output/error.

Hello All,

1) Sorry, I posted no follow ups but fress posts (twice) before noticing. Will not repeat this.

2) just tried testcgiapp --input=mycgi.cgi
This also returns silently w/o any other output.
The path to the htmls is also valid.

Where and how is the CGI input processed?

I see only a TFPWebmodule type object in my code
(and the DataModuleRequest method to handle the request..) and a RegisterHTTPModule() in the main of the program.

Is there anything that I need to initialize(which might be done correctly under Windows but needs an extra step under Linux)?

Kind Regards,

Christian

Hello,

Thx for the hint: I have already removed the writelns. (I was already aware that standard console out in the case of a CGI belongs _only_ to webpage output)

Kind Regards,

Christian

You need to fill DataModuleRequest with code; It should put something in response, and then call Response.SendResponse. If you don't, nothing will happen.

Michael.

You need to fill DataModuleRequest with code; It should put something in response, and then call Response.SendResponse. If you don't, nothing will happen.

The source of the problem might be located in the unit between my ears ;-O

Looks as if I misunderstood something.
- FCL-Web is a Lazarus based unit. So Lazarus takes care of creating and initializing the objects (So the DataModule) Just wondering why I still got some Lazarus functionality in when saving the data module unit code as a pas file and compiling under fpc.
- So my working enviroment was Lazarus specific (and not Win32) and my not working version was FPC (and not caused by Linux)
- Will boot up the windows again and verify

==== Case closed ====

I simply was not aware that a certain amount of objects must be alive in an application to use FCL-WEB / CGI. If based (again) on the Lazarus samples and a Lazarus created 'CGIApplication' (with a Webmodule Form) - then it works just fine :-)

Thx again for the fine support and greetings to all that 'Pascaleros' out there! Hope I will soon be able to contribute something(most likely about ARM9 embedded linux)

Christian