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Posted to users@tomcat.apache.org by Christoph Kukulies <ku...@gilberto.physik.rwth-aachen.de> on 2000/05/10 16:04:31 UTC
OT: java programming Q
The more I'm playing with servlets the more I like it and the more
I'm moving the CGI program parts to servlets.
But for efficiency reasons there's a lot I'd still prefer to be done with CGI
programs (C programs).
One thing I found when I tried to concentrate several buttons in
an ACTION=/servlets/Some which should dispatch dependent on the button
pressed.
As long as I stay in Java, everything is fine.
Now I want to exec my CGI-C program and the whole CGI context gets lost,
even the outputstream.
I'm using java.lang.Runtime exec() for this.
Is there a way to let the exec'ed process inherit the environment?
Don't know how this could be achieved but writing everything
in Java would be too much for the moment.
E.g:
public void doGet (HttpServletRequest request,
HttpServletResponse response)
throws ServletException, IOException
{
String type = request.getParameter("type");
if(type.compareTo("Reportausgabe")==0){
out.println("Reportausgabe");
try {
out.println("executing...");
action="/usr/local/www/cgi-bin/test.sh";
runner.exec(action);
} catch(Exception e) {
out.println("EXEC error");
out.flush();
e.printStackTrace();
}
return;
}
You can also email me directly if this pollutes the list.
--
Chris Christoph P. U. Kukulies kuku@gil.physik.rwth-aachen.de
Re: OT: java programming Q
Posted by Christoph Kukulies <ku...@gilberto.physik.RWTH-Aachen.DE>.
On Wed, May 10, 2000 at 08:33:10AM -0600, M Butcher wrote:
> So the servlet executes a C program? And the C program doesn't behaive as
> expected? That is probably because none of the CGI environment variables are set
> for the program. You are executing it outside of the normal CGI context, so any
> particular information that _was_ being sent to the CGI (in the form of env. vars
> or arguments) is now being sent to the servlet engine. If you really want to make
> this method work, you need to have the java set all of the correct environment
> variables for the C program.
Yes, I understand this so. I could pick up
the CGI environment in the java code and then pass them as
commandline arguments or something to the C programs.
The only thing I'm still wondering about is how I can for example
make the C program sending it's stdout to
PrintWriter out = response.getWriter(); , in other words, can I write a
C program cprog or bourne shell script:
main() { printf("<HTML>Hello World</HTML>"};
and exec this C program from within the servlet
String action="cprog";
Runtime runner= Runtime.getRuntime();
runner.exec(action);
This doesn't seem to work. And I havn't yet found where the output
goes at all.
--
Chris Christoph P. U. Kukulies kuku@gil.physik.rwth-aachen.de
>
> Christoph Kukulies wrote:
>
> > The more I'm playing with servlets the more I like it and the more
> > I'm moving the CGI program parts to servlets.
> >
> > But for efficiency reasons there's a lot I'd still prefer to be done with CGI
> > programs (C programs).
> >
> > One thing I found when I tried to concentrate several buttons in
> > an ACTION=/servlets/Some which should dispatch dependent on the button
> > pressed.
> >
> > As long as I stay in Java, everything is fine.
> >
> > Now I want to exec my CGI-C program and the whole CGI context gets lost,
> > even the outputstream.
> >
> > I'm using java.lang.Runtime exec() for this.
> >
> > Is there a way to let the exec'ed process inherit the environment?
> > Don't know how this could be achieved but writing everything
> > in Java would be too much for the moment.
> >
> > E.g:
> >
> > public void doGet (HttpServletRequest request,
> > HttpServletResponse response)
> > throws ServletException, IOException
> > {
> > String type = request.getParameter("type");
> > if(type.compareTo("Reportausgabe")==0){
> > out.println("Reportausgabe");
> > try {
> > out.println("executing...");
> > action="/usr/local/www/cgi-bin/test.sh";
> > runner.exec(action);
> > } catch(Exception e) {
> > out.println("EXEC error");
> > out.flush();
> > e.printStackTrace();
> > }
> > return;
> > }
> >
> > You can also email me directly if this pollutes the list.
> >
> > --
> > Chris Christoph P. U. Kukulies kuku@gil.physik.rwth-aachen.de
Re: OT: java programming Q
Posted by M Butcher <mb...@uswest.net>.
So the servlet executes a C program? And the C program doesn't behaive as
expected? That is probably because none of the CGI environment variables are set
for the program. You are executing it outside of the normal CGI context, so any
particular information that _was_ being sent to the CGI (in the form of env. vars
or arguments) is now being sent to the servlet engine. If you really want to make
this method work, you need to have the java set all of the correct environment
variables for the C program.
Christoph Kukulies wrote:
> The more I'm playing with servlets the more I like it and the more
> I'm moving the CGI program parts to servlets.
>
> But for efficiency reasons there's a lot I'd still prefer to be done with CGI
> programs (C programs).
>
> One thing I found when I tried to concentrate several buttons in
> an ACTION=/servlets/Some which should dispatch dependent on the button
> pressed.
>
> As long as I stay in Java, everything is fine.
>
> Now I want to exec my CGI-C program and the whole CGI context gets lost,
> even the outputstream.
>
> I'm using java.lang.Runtime exec() for this.
>
> Is there a way to let the exec'ed process inherit the environment?
> Don't know how this could be achieved but writing everything
> in Java would be too much for the moment.
>
> E.g:
>
> public void doGet (HttpServletRequest request,
> HttpServletResponse response)
> throws ServletException, IOException
> {
> String type = request.getParameter("type");
> if(type.compareTo("Reportausgabe")==0){
> out.println("Reportausgabe");
> try {
> out.println("executing...");
> action="/usr/local/www/cgi-bin/test.sh";
> runner.exec(action);
> } catch(Exception e) {
> out.println("EXEC error");
> out.flush();
> e.printStackTrace();
> }
> return;
> }
>
> You can also email me directly if this pollutes the list.
>
> --
> Chris Christoph P. U. Kukulies kuku@gil.physik.rwth-aachen.de
>
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--
M Butcher
mailto:mbutcher@<NOSPAM>xleration.com