cgi problem

[Paul Rubin]

I'm trying to write a simple cgi that reads a post from the user's
browser, does some stuff with the form data, and redirects the browser
back to the originating url, i.e. I want the cgi to send a 302
redirect.

There's no obvious way in the cgi module to set the response code to
anything but 200. I.e. the run_cgi method automatically sends the 200
response without giving any way to suppress it (like nph-whatever in
Apache). Is that a missing feature that I should add, or am I trying
to do something dumb?

Thanks.

[Kent Johnson]

Re: cgi problem

Paul Rubin wrote:[color=blue]
> I'm trying to write a simple cgi that reads a post from the user's
> browser, does some stuff with the form data, and redirects the browser
> back to the originating url, i.e. I want the cgi to send a 302
> redirect.
>
> There's no obvious way in the cgi module to set the response code to
> anything but 200. I.e. the run_cgi method automatically sends the 200
> response without giving any way to suppress it (like nph-whatever in
> Apache). Is that a missing feature that I should add, or am I trying
> to do something dumb?[/color]

Set the Location: header to the new URL.

http://hoohoo.ncsa.uiuc.edu/cgi/out.html

http://www.algonet.se/~ug/html+pycgi/redirect.html

Kent

[Thomas Guettler]

Re: cgi problem

Am Wed, 08 Mar 2006 00:19:55 -0800 schrieb Paul Rubin:
[color=blue]
> I'm trying to write a simple cgi that reads a post from the user's
> browser, does some stuff with the form data, and redirects the browser
> back to the originating url, i.e. I want the cgi to send a 302
> redirect.[/color]

Hi,

I have this setup for a small script (for bigger things I use quixote)



def cgi_main():
stdout=sys.stdo ut
sys.stdout=sys. stderr # print soll zu Apache-Log
try:
html=cgi_html()
except ReturnThis, r:
stdout.write(st r(r))
return
stdout.write("C ontent-Type: text/html\n\n%s" % html)

CGI-Script *very* small
............
# Python Imports
import os
import sys

import cgitb
cgitb.enable()
import foo

if __name__=="__ma in__":
foo.cgi_main()

.............

file foo:

def cgi_main():
stdout=sys.stdo ut
sys.stdout=sys. stderr # print should go to Apache-Log
try:
html=cgi_html()
except ReturnThis, r:
stdout.write(st r(r))
return
stdout.write("C ontent-Type: text/html\n\n%s" % html)


class ReturnThis(Exce ption):
pass

class Redirect(Return This):
def __init__(self, destination):
if os.environ.get( "HTTPS")==" on":
http="https://"
else:
http="http://"
url="%s%s%s%s" % (http, os.environ["SERVER_NAM E"], os.environ["SCRIPT_NAM E"],
destination)
header="Status: 302 Moved Temporarily\nLo cation: %s\n\n" % (
url)
ReturnThis.__in it__(self, header)


Now you can 'raise Redirect("myloc ation")' anywhere in your code.

HTH,
Thomas

--
Thomas Güttler, http://www.thomas-guettler.de/
E-Mail: guettli (*) thomas-guettler + de
Spam Catcher: niemand.leerman n@thomas-guettler.de

[Paul Rubin]

Re: cgi problem

Thomas Guettler <niemand.leerma nn@thomas-guettler.de> writes:[color=blue][color=green]
> > back to the originating url, i.e. I want the cgi to send a 302 redirect.[/color]
>
> I have this setup for a small script (for bigger things I use quixote)...[/color]

Thanks. It looks like you've written your cgi completely from
scratch. I was hoping to use the cgi module, which has some
convenient features for reading the query parameters and POST content.
I should look into Quixote and some of the other Python web frameworks
but this particular task is pretty simple so I thought I'd just use a cgi.

[Tim Roberts]

Re: cgi problem

Paul Rubin <http://phr.cx@NOSPAM.i nvalid> wrote:[color=blue]
>
>Thomas Guettler <niemand.leerma nn@thomas-guettler.de> writes:[color=green][color=darkred]
>> > back to the originating url, i.e. I want the cgi to send a 302 redirect.[/color]
>>
>> I have this setup for a small script (for bigger things I use quixote)...[/color]
>
>Thanks. It looks like you've written your cgi completely from
>scratch. I was hoping to use the cgi module, which has some
>convenient features for reading the query parameters and POST content.[/color]

Yes, but the CGI module doesn't write anything, so the advice of writing a
"Location:" header still applies.
--
- Tim Roberts, timr@probo.com
Providenza & Boekelheide, Inc.

[Paul Rubin]

Re: cgi problem

Tim Roberts <timr@probo.com > writes:[color=blue]
> Yes, but the CGI module doesn't write anything, so the advice of writing a
> "Location:" header still applies.[/color]

Aha, it's coming from CGIHTTPServer.p y:CGIHTTPReques tHandler.run_cg i()
where it says

self.send_respo nse(200, "Script output follows")

I got the two modules confused. This still leaves me with the same
basic problem, how to suppress the sending of that header.

Thanks.

[Kent Johnson]

Re: cgi problem

Paul Rubin wrote:[color=blue]
> Tim Roberts <timr@probo.com > writes:
>[color=green]
>>Yes, but the CGI module doesn't write anything, so the advice of writing a
>>"Location:" header still applies.[/color]
>
>
> Aha, it's coming from CGIHTTPServer.p y:CGIHTTPReques tHandler.run_cg i()
> where it says
>
> self.send_respo nse(200, "Script output follows")
>
> I got the two modules confused. This still leaves me with the same
> basic problem, how to suppress the sending of that header.[/color]

Ah, now I get it. This does look like a bug in CGIHTTPServer to me. As
you note, it hardcodes the 200 status response. The CGI spec says that
the CGI program can use the Status: header to tell the server what
status code to send but CGIHTTPServer doesn't do that.

ISTM the spec requires the server to buffer and interpret the HTTP
headers from the CGI so the Status header can be set based on the CGI
response.

[Thomas Guettler]

Re: cgi problem

Am Thu, 09 Mar 2006 00:35:25 -0800 schrieb Paul Rubin:
[color=blue]
> Tim Roberts <timr@probo.com > writes:[color=green]
>> Yes, but the CGI module doesn't write anything, so the advice of writing a
>> "Location:" header still applies.[/color]
>
> Aha, it's coming from CGIHTTPServer.p y:CGIHTTPReques tHandler.run_cg i()
> where it says
>
> self.send_respo nse(200, "Script output follows")
>
> I got the two modules confused. This still leaves me with the same
> basic problem, how to suppress the sending of that header.[/color]

I had this problem, too:

https://sourceforge.net/tracker/?func=detail&atid=305470&aid=1055159&group_id=5470

CGIHTTPServer writes "200" before the script gets executed!

You can return this:
"""<html>
<head>
<meta http-equiv="refresh"
content="1; url=...">
</head>
</html>"""


Thomas

--
Thomas Güttler, http://www.thomas-guettler.de/
E-Mail: guettli (*) thomas-guettler + de
Spam Catcher: niemand.leerman n@thomas-guettler.de