httpd-users mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Peter Milanese <>
Subject Re: [users@httpd] Re: snooping on cgi data
Date Thu, 04 Oct 2007 15:21:09 GMT

Eric, your post comes across a bit abbrasive.

Wireshark (etherreal) is a totally different animal.

You failed to mention what operating system you are running on your servers.

What I _think_ you want to do is TRACE the process, to see what calls it is making to what.
This can be done using TRUSS or STRACE.

The other route is to include debug code in your CGIs. You also failed to mention what type
of CGIs they are.

----- Original Message ----
From: Eric S. Johansson <>
Sent: Thursday, October 4, 2007 7:47:31 AM
Subject: [users@httpd]  Re: snooping on cgi data

Joshua Slive wrote:
> On 10/3/07, Eric S. Johansson <> wrote:
>> are there any tools/techniques for snooping on the data sent to and from a cgi
>> program?  I'm thinking something like wireshark for webservers.
> I think you should be more specific about what you are trying to
> accomplish. You can try the ScriptLog directive, but really the info
> sent to and from CGI scripts is almost identical to the info sent to
> and from the http server itself. There is only a little header
> manipulation and some environment variables set.

What I'm specifically trying to accomplish is what I said.  I want to be able to 
snoop on the data stream to and from a CGI program.  What's driving me in this 
direction is that I occasionally get errors in the output of the CGI in which 
causes the Web server to throw up a 500 message and put totally useless debug 
information into the error log.  If I can look at the stream, I can usually 
determine the source of the problem and a fix much more quickly than I can with 
any other technique.  For example, right now I have an errant print statement 
somewhere in my code.  I'm having to go through all the print statements listed 
and tried to determine which one is the message getting in the way.  If I can 
look at the Stream, I would be able to find the text Apache strips out before 
dumping to the error log and home in on the message location.

So, unless you have a different suggestion, I believe some method of looking at 
the data streams to and from the CGI would be what I need.


The official User-To-User support forum of the Apache HTTP Server Project.
See <URL:> for more info.
To unsubscribe, e-mail:
   "   from the digest:
For additional commands, e-mail:

Yahoo! oneSearch: Finally, mobile search 
that gives answers, not web links.
View raw message