[SLUG] HTTP_REFERER not found [Repost]
Hi Sluggers: I subscribed with a new email address. So I am reposting my query on this. Setup: Url comes to site like this http://www.yourdomain.com/index.html?hop=some_data Q1. If I click on a link to go to another HTML page say name.html, I lose the "hop=some_data" part. How do I make the "hop=some_data" go with the "name.html" with the tag from an HTML document ? Is this possible or a script can do this only ? Q2. The order page calls a Perl script say "orderpage.pl", I want the script to capture the "hop=some_data". I got the script to print the whole %ENV, and I see no "HTTP_REFERER". I thought "HTTP_REFERER" would show the url that called "orderpage.pl" with the "hop=some_data" . But if I cannot see "HTTP_REFERER", then how do I get the script to capture the "hop=some_data" ? Thank You. -- SLUG - Sydney Linux User's Group - http://slug.org.au/ More Info: http://lists.slug.org.au/listinfo/slug
Re: [SLUG] HTTP_REFERER not found [Repost]
On Tue, Sep 30, 2003 at 10:19:01AM +1000, [EMAIL PROTECTED] wrote: > Q2. The order page calls a Perl script say "orderpage.pl", I want the > script to capture the "hop=some_data". I got the script to print the whole > %ENV, and I see no "HTTP_REFERER". I thought "HTTP_REFERER" would show the That's because it's not the referrer. The referrer is the page containing the link that was used to get to your page. The stuff after the '?' is QUERY_STRING. To pick a random example, http://www.slug.org.au/index.html contains this link: Sydney Linux Users Group (SLUG) If I follow the link to load "about.html", HTTP_REFERER will be "http://www.slug.org.au/index.html"; and QUERY_STRING will be empty. To pick another random example, slug's events page contains this link: If I follow that link, HTTP_REFERER will be "http://www.slug.org.au/events/"; and QUERY_STRING will be "id=91". Cheers, John -- whois [EMAIL PROTECTED] GPG key id: 0xD59C360F http://kirriwa.net/john/ -- SLUG - Sydney Linux User's Group - http://slug.org.au/ More Info: http://lists.slug.org.au/listinfo/slug
Re: [SLUG] HTTP_REFERER not found [Repost]
> Q1. If I click on a link to go to another HTML page say name.html, I > lose the "hop=some_data" part. How do I make the "hop=some_data" go with > the "name.html" with the tag from an HTML document ? Is this > possible or a script can do this only ? This is not how a relative link works. Everything after the last '/' is lost. However with enough creativity anything can be made possible in Javascript. > > Q2. The order page calls a Perl script say "orderpage.pl", I want the > script to capture the "hop=some_data". I got the script to print the > whole %ENV, and I see no "HTTP_REFERER". I thought "HTTP_REFERER" would > show the url that called "orderpage.pl" with the "hop=some_data" . But > if I cannot see "HTTP_REFERER", then how do I get the script to capture > the > "hop=some_data" ? You should be seeing the previouse URL in the environment variable HTTP_REFERER. Contrary to what someone else said it will contain the query data. It might not exists because the browser is not sending it. Look at the HTTP traffic with a sniffer to verify the browser is sending it. Some more information about what web server you're using will help fix the problem too. -- Cult - A sociotype of an auto-toxic meme-complex, composed of membots and/or memeoids. Memetic Lexicon : http://pespmc1.vub.ac.be/MEMLEX.html -- SLUG - Sydney Linux User's Group - http://slug.org.au/ More Info: http://lists.slug.org.au/listinfo/slug
RE: [SLUG] HTTP_REFERER not found [Repost]
>Q1. If I click on a link to go to another HTML page say name.html, I lose
>the "hop=some_data" part. How do I make the "hop=some_data" go with the
>"name.html" with the tag from an HTML document ? Is this possible or a
>script can do this only ?
there are a couple ways -
one way is to add the "hop=some_data" to the href itself, IF it is a static
string... ie: http://www.domain.com/name.html?hop=some_data";>
otherwise, you can implement a simple CGI/Perl script to generate the
index page from a template...
>Q2. The order page calls a Perl script say "orderpage.pl", I want the
>script to capture the "hop=some_data". I got the script to print the whole
>%ENV, and I see no "HTTP_REFERER". I thought "HTTP_REFERER" would show the
>url that called "orderpage.pl" with the "hop=some_data" . But if I cannot
>see "HTTP_REFERER", then how do I get the script to capture the
>"hop=some_data" ?
The ENV variable you are looking for is definitely the QUERY_STRING...
or use STDIN to retrieve POST data...
If you are using perl (looks like you are using a hash there - %ENV) then
you can
either use the CGI module to retrieve the query strings, in which case you
don't
have to worry about that at all, or you can do something like this -
my %formData;
read STDIN, $_, $ENV{'CONTENT_LENGTH'}; #Read in STDIN to default
variable...
%formData = split/&|=/; #Place separate keys/values into
'formData' hash, split by '&' and '='
if (!%formData) #- If we didn't get anything
from POST method,
{
$_ = $ENV{'QUERY_STRING'};# try retrieving it from
QUERY_STRING (GET method)
%formData = split/&|=/; # and split like before.
}
Then to access the data, you would go:
my $hop = $formData{'hop'};
This is a quick hack - CGI module is much better & more efficient
eg. what happens when you get a number of values from in
this code?
--
SLUG - Sydney Linux User's Group - http://slug.org.au/
More Info: http://lists.slug.org.au/listinfo/slug
Re: [SLUG] HTTP_REFERER not found [Repost]
>> Q1. If I click on a link to go to another HTML page say name.html, I >> lose the "hop=some_data" part. How do I make the "hop=some_data" go >> with the "name.html" with the tag from an HTML document ? Is this >> possible or a script can do this only ? > > This is not how a relative link works. Everything after the last '/' is > lost. However with enough creativity anything can be made possible in > Javascript. I'll see if there are any javascript already available to do this. Or I might just write a Perl script like the order page one I got. > >> >> Q2. The order page calls a Perl script say "orderpage.pl", I want the >> script to capture the "hop=some_data". I got the script to print the >> whole %ENV, and I see no "HTTP_REFERER". I thought "HTTP_REFERER" >> would show the url that called "orderpage.pl" with the "hop=some_data" >> . But if I cannot see "HTTP_REFERER", then how do I get the script to >> capture the >> "hop=some_data" ? > > You should be seeing the previouse URL in the environment variable > HTTP_REFERER. Contrary to what someone else said it will contain the > query data. It might not exists because the browser is not sending it. > Look at the HTTP traffic with a sniffer to verify the browser is sending > it. Some more information about what web server you're using will help > fix the problem too. > Well I am using a Red Hat Linux 7.3 running Apache server. Does this help ?Not sure sure what u mean by use a sniffer (please clarify). I just printed out the %ENV hash, and saw no HTTP_REFERER there. -- SLUG - Sydney Linux User's Group - http://slug.org.au/ More Info: http://lists.slug.org.au/listinfo/slug
RE: [SLUG] HTTP_REFERER not found [Repost]
>>Q1. If I click on a link to go to another HTML page say name.html, I
>> lose the "hop=some_data" part. How do I make the "hop=some_data" go
>> with the "name.html" with the tag from an HTML document ? Is this
>> possible or a script can do this only ?
>
> there are a couple ways -
> one way is to add the "hop=some_data" to the href itself, IF it is a
> static string... ie:href="http://www.domain.com/name.html?hop=some_data";> otherwise, you can
> implement a simple CGI/Perl script to generate the index page from a
> template...
Well the "hop=some_data" is dynamic. Looks like a script is required to do
this then, and pass it dynamically to all tag on the page being viewed
so that when a new page is clicked on, the "hop=some_data" is preserved.
>
>
>>Q2. The order page calls a Perl script say "orderpage.pl", I want the
>> script to capture the "hop=some_data". I got the script to print the
>> whole %ENV, and I see no "HTTP_REFERER". I thought "HTTP_REFERER" would
>> show the url that called "orderpage.pl" with the "hop=some_data" . But
>> if I cannot see "HTTP_REFERER", then how do I get the script to capture
>> the
>>"hop=some_data" ?
>
> The ENV variable you are looking for is definitely the QUERY_STRING...
> or use STDIN to retrieve POST data...
Well from the page
http://www.yourdomain.com/index.html?hop=some_data
I clicked on a link for the order page which has this
http://www.yourdomain.com/cgi-bin/orderpage.pl?value=some_data_the_order_script_uses";>
This shows QUERY_STRING as
value=some_data_the_order_script_uses
It looks like I need to somehow parse the "hop=some_data" dynamically to
the "orderpage.pl" scripts so that when clicked it has this
href="http://www.yourdomain.com/cgi-bin/orderpage.pl?value=some_data_the_order_script_uses&hop=some_data";
Any other way I can do this ?
>
> If you are using perl (looks like you are using a hash there - %ENV)
> then you can
> either use the CGI module to retrieve the query strings, in which case
> you don't
> have to worry about that at all, or you can do something like this -
>
>
> my %formData;
>
> read STDIN, $_, $ENV{'CONTENT_LENGTH'}; #Read in STDIN to default
> variable...
> %formData = split/&|=/; #Place separate keys/values
> into 'formData' hash, split by '&' and '='
> if (!%formData) #- If we didn't get
> anything from POST method,
> {
>$_ = $ENV{'QUERY_STRING'};# try retrieving it from
> QUERY_STRING (GET method)
>%formData = split/&|=/; # and split like before.
> }
>
>
> Then to access the data, you would go:
> my $hop = $formData{'hop'};
>
> This is a quick hack - CGI module is much better & more efficient
> eg. what happens when you get a number of values from
> in
> this code?
>
Thanks for this piece of code. I already have a read_input() sub doing
something similar.
--
SLUG - Sydney Linux User's Group - http://slug.org.au/
More Info: http://lists.slug.org.au/listinfo/slug
Re: [SLUG] HTTP_REFERER not found [Repost]
[EMAIL PROTECTED] wrote: Hi Sluggers: I subscribed with a new email address. So I am reposting my query on this. Setup: Url comes to site like this http://www.yourdomain.com/index.html?hop=some_data Q1. If I click on a link to go to another HTML page say name.html, I lose the "hop=some_data" part. How do I make the "hop=some_data" go with the "name.html" with the tag from an HTML document ? Is this possible or a script can do this only ? Q2. The order page calls a Perl script say "orderpage.pl", I want the script to capture the "hop=some_data". I got the script to print the whole %ENV, and I see no "HTTP_REFERER". I thought "HTTP_REFERER" would show the url that called "orderpage.pl" with the "hop=some_data" . But if I cannot see "HTTP_REFERER", then how do I get the script to capture the "hop=some_data" ? OK, read this answer as more philosophical than anything else. Firstly: Hi education (or whatever your name is). I run a company that does web design and programming in a Linux environment. We know all of the answers to all of your problems. We do HTML, Perl, CGI, PHP, and even Cold Fusion if we have to. Our rates are very reasonable. Our web site is here: http://www.babel.com.au/ You can find our contact details there. end of plug. Now for the philosophical bit. I could answer your question. I won't. The reason I won't do so on the SLUG list is primarily because I'd be undercutting my own business doing so. It sounds like you are either writing or getting written or modifying a commercial web application of some kind here, of the type that accepts orders, has people pay money, and earns you some kind of profit. Not that I have a problem with that. It's good that Linux gets used in this sort of environment and I think you'll find that one of Linux's great strengths is the stability and robustness of the code base that goes into such products as Apache, PHP, mod_ssl, the kernel, Perl, etc, that make your kind of project possible. I am quite happy to help even the most casual interlopers on the SLUG list that are playing with web site programming perhaps as a hobby, perhaps for a uni project (but I won't do your homework for you), or perhaps for their school fete or church fair. I think, however, that offering free advice on design and programming of what _sounds a lot_ like a commercial project (not saying it is, just it sounds a lot like one, and if it isn't perhaps you should give us some more information) is moderately unfair. It's unfair to the companies (like mine) that try to employ people making a living out of this sort of thing, and unfair to the people who do the development of free software that aren't getting the pay back from work like yours that they might get if it were channelled through companies like mine, Anthony's, or even IBM (I know I contribute modestly in a financial sense to free software, IBM does extensively, and I guess Everything Linux does to some extent somewhere along the supply chain too). So. Are you following this so far? Yes, I'd be happy to help. It sounds like you're out of your depth a bit. More importantly, it sounds like you're trying to pass around HTTP GET variables between web pages, something that is inherently unsafe and extremely vulnerable to external attack. It sounds like you need some professional assistance, and I suggest you get some. You need to find someone who knows all about session management, session encryption probably, web based authentication methodologies, and safe data encapsulation in session code. You are certain to find people here that will help you short or long term, and even more certain to find people on [EMAIL PROTECTED] that will do likewise. End of philosophical bit. Start of SLUG committee / mailing list management bit. Spam wars aside, is there an official SLUG policy on this sort of thing on the SLUG list? I know there are mumbled-in-beard words about not-using-the-list-for-commercial-purposes from time to time, but what's the official published policy? Should there be one? Back to your regularly scheduled flame war. Hey, at least we're not arguing about distros at the moment. -- Del -- SLUG - Sydney Linux User's Group - http://slug.org.au/ More Info: http://lists.slug.org.au/listinfo/slug
Re: [SLUG] HTTP_REFERER not found [Repost]
On Tue Sep 30, 2003 at 18:24:09 +1000, Del wrote: >[EMAIL PROTECTED] wrote: >>Hi Sluggers: >> >>I subscribed with a new email address. So I am reposting my query on this. >> >>Setup: >>Url comes to site like this >> >>http://www.yourdomain.com/index.html?hop=some_data >> >>Q1. If I click on a link to go to another HTML page say name.html, I lose >>the "hop=some_data" part. How do I make the "hop=some_data" go with the >>"name.html" with the tag from an HTML document ? Is this possible or a >>script can do this only ? >> >>Q2. The order page calls a Perl script say "orderpage.pl", I want the >>script to capture the "hop=some_data". I got the script to print the whole >>%ENV, and I see no "HTTP_REFERER". I thought "HTTP_REFERER" would show the >>url that called "orderpage.pl" with the "hop=some_data" . But if I cannot >>see "HTTP_REFERER", then how do I get the script to capture the >>"hop=some_data" ? > >OK, read this answer as more philosophical than anything else. > > >Back to your regularly scheduled flame war. Hey, at least we're >not arguing about distros at the moment. <-- snip --> I think a lot of people who are posting here are probably having problem running linux in their business and come to slug for help. I don't see this as a problem at all. I think the only difference here is in degrees, there is a difference between "how do i do XYZ" and "please teach me how to write a dynamic web application", but i think in general, if the slug list can't help those using linux at work, then what is the point?! Benno (not speaking on behalf of the committee) -- SLUG - Sydney Linux User's Group - http://slug.org.au/ More Info: http://lists.slug.org.au/listinfo/slug
Re: [SLUG] HTTP_REFERER not found [Repost]
Del <[EMAIL PROTECTED]> writes: > [EMAIL PROTECTED] wrote: Your email address makes my skin crawl :) >> Hi Sluggers: >> see "HTTP_REFERER", then how do I get the script to capture the >> "hop=some_data" ? > > OK, read this answer as more philosophical than anything else. One of the strengths of FOSS is its community and support. That support comes in many flavours, there's commercial support, web sites, news and mailing list archives, books (online and dead tree) and live news groups and mailing lists. One of the most important skills to learn is how to find and use the support that's available. If you only use one of the available support options, you're not utilising of one FOSS's strengths to your advantage. Unless there is some reason to write your web site from scratch in perl, there might be better alternatives. embperl and html-mason come to mind for perl options, they might have the features you're trying to write already built in and well tested. They both have strong communities that have been there, done that. Zope and php are another alternative to perl, php in particular has a very strong community and all of the features you want already built. There's a lot of knowledge about building web sites within the php community, even if you don't want to use php, you can learn a lot about designing web sites (and programs in general) from them. And there's probably stacks of open source "shopping cart", etc, applications kicking around. A good thing to do is research what other people are using and how they are using them, and popularity should also be taken in to account (but shouldn't be the only thing to look at). -- SLUG - Sydney Linux User's Group - http://slug.org.au/ More Info: http://lists.slug.org.au/listinfo/slug
RE: [SLUG] HTTP_REFERER not found [Repost]
Hi Sluggers: Did not realise that this post would cause an issue. I never read the mailing list rules. Anyway I have sorted out my problem. Thanks to those who gave suggestions. Del: I do have a name. It's Louis. I'll keep your business url should I need business assistance. I don't know the list rules but isn't that a way of spamming the list by mentioning business urls in the list ?? Cheers. -- SLUG - Sydney Linux User's Group - http://slug.org.au/ More Info: http://lists.slug.org.au/listinfo/slug
Re: [SLUG] HTTP_REFERER not found [Repost]
>I think a lot of people who are posting here are probably having problem >running linux in their business and come to slug for help. I don't see >this as a problem at all. I think the only difference here is in degrees, >there is a difference between "how do i do XYZ" and "please teach me how >to write a dynamic web application", but i think in general, if the slug >list can't help those using linux at work, then what is the point?! 10-4 That's exactly how I found my way onto this list. :) And I do agree whole-heartedly about: "there is a difference between "how do i do XYZ" and "please teach me how to write a dynamic web application"," I have learnt a lot between this list & the perl list I'm subscribed to as well - There is also only so much you can learn by asking [relatively] simple questions like those passed around here (some are not quite so simple, but the majority are) The rest we'll have to dig deeper... But we'll also have to respect the businesses, so yeah. I think it would be silly to ask something like: eg. "I need a script to manage my customer database and handle all my orders" But I see no problem in the questions so far where the need is smaller: eg. "I can't find an appropriate module to connect to a database using perl - can anyone point me in the right direction?" We're all here to learn. (I'm sure you know what I mean...):) -- Jared <>-- SLUG - Sydney Linux User's Group - http://slug.org.au/ More Info: http://lists.slug.org.au/listinfo/slug
Re: [SLUG] HTTP_REFERER not found [Repost]
That's exactly how I found my way onto this list. :) And I do agree whole-heartedly about: "there is a difference between "how do i do XYZ" and "please teach me how to write a dynamic web application"," Yup, fair cop. Note that my post on why I won't answer this sort of question on the SLUG list was more philosophical. I guess I had two main points: (a) I reserve the right to charge for doing work that I think I should be able to charge for, while still answering questions that are simple and easy and about doing XYZ, and (b) Louis (Hi Louis!) is going to be in serious danger if he proceeds down the passing-variables-via-GET method of web programming and probably needs some more serious help than can be provided in a 2 minute Q&A session on SLUG. There is also only so much you can learn by asking [relatively] simple questions like those passed around here (some are not quite so simple, but the majority are) The rest we'll have to dig deeper... Agreed, and I guess this was one of my points. Louis: It might be reasonably easy to get your HTTP variables passed around by the method you're talking about but you're going to at least need to find a good book on CGI and perl and read a bit about web security to find out why it's a really bad idea to try to do what you're doing, except for very trivial applications. i.e. you might get a simple answer to a simple problem here, but I think you're going to end up with the right answer to the wrong problem. Unrelated web programming add-on: There is a Sydney PHP user group meeting on tomorrow (Thursday 2nd October) at UTS. Details here: http://sydney.ug.php.net/ sydney.ug.php.net is not associated with SLUG, or the folks who make PHP (but they let us use an A record in their domain). -- Del -- SLUG - Sydney Linux User's Group - http://slug.org.au/ More Info: http://lists.slug.org.au/listinfo/slug
RE: [SLUG] HTTP_REFERER not found [Repost]
>Louis (Hi Louis!) is going to be in serious >danger if he proceeds down the passing-variables-via-GET method >of web programming lol :P POST is better - but only coz it's invisible to the human eye. Session variables are better still, but use in moderation... Also a good dose of SSL won't hurt ;) And I love databases! Very satsifying to see all your data saved efficiently and cleanly - with easy access later. But I leave that up to you Louis... check out some different methods, or maybe get some professional help :) -Jazza -- SLUG - Sydney Linux User's Group - http://slug.org.au/ More Info: http://lists.slug.org.au/listinfo/slug
