how to check if a remote file exists

[hofar...@houseoffusion.com]

hi,

i have w2k3 server that holds a text file, say x.txt, generated by an VFP9 app., on a separate server i have a cf9 app. that needs to check for file x, if it exists get a copy of it and merge it with another text file that is generated by the app.
well, how can i do the checking part?

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[hofar...@houseoffusion.com]

You can use fileExists w/ a URL but unfortunately, if the server has a 404
handler than it will return true even when the 404 handler fires.

<cfif fileExists("http://www.raymondcamden.com/index2332.cfm")>
yes
</cfif>

<cfhttp url="http://www.raymondcamden.com/index2332.cfm">
<cfdump var="#cfhttp#">

If a 404 handler isn't there, then this would have worked.

Archive: http://www.houseoffusion.com/groups/cf-talk/message.cfm/messageid:358221

[hofar...@houseoffusion.com]

> You can use fileExists w/ a URL but unfortunately, if the server has a 404
> handler than it will return true even when the 404 handler fires.
>
> <cfif fileExists("http://www.raymondcamden.com/index2332.cfm")>
> yes
> </cfif>
>
> <cfhttp url="http://www.raymondcamden.com/index2332.cfm">
> <cfdump var="#cfhttp#">
>
> If a 404 handler isn't there, then this would have worked.

If you're building a 404 handler, you should actually make sure it
returns a 404 status code. You can do this easily enough with
CFHEADER. The page can contain whatever HTML you want to present to
the user, still.

I run into this quite a bit working with the Google Search Appliance.
The GSA relies on status codes by default to identify which pages to
index. While it's possible to give it a way to identify soft 404s
(http://en.wikipedia.org/wiki/HTTP_404#Soft_404), it's much easier
just to have real 404s in the first place.

Dave Watts, CTO, Fig Leaf Software
1-202-527-9569
http://www.figleaf.com/
http://training.figleaf.com/

Fig Leaf Software is a Veteran-Owned Small Business (VOSB) on
GSA Schedule, and provides the highest caliber vendor-authorized
instruction at our training centers, online, or onsite.

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[hofar...@houseoffusion.com]

Oh good point there. So - ignoring my server where I don't have a proper
404 (grin), this should work for you:

<cfhttp url="http://www.cnn.com/index2332.cfm">
<cfif cfhttp.responseheader.status_code is 200>
good
</cfif>

Archive: http://www.houseoffusion.com/groups/cf-talk/message.cfm/messageid:358231

[hofar...@houseoffusion.com]

> Oh good point there. So - ignoring my server where I don't have a proper
> 404 (grin), this should work for you:
>
> <cfhttp url="http://www.cnn.com/index2332.cfm">
> <cfif cfhttp.responseheader.status_code is 200>
> good
> </cfif>

Your original point is perfectly valid, though - lots of people don't
return proper status codes. So it is useful to have some additional
logic to deal with soft 404s if you're testing against unfamiliar
servers.

Dave Watts, CTO, Fig Leaf Software
1-202-527-9569
http://www.figleaf.com/
http://training.figleaf.com/

Fig Leaf Software is a Veteran-Owned Small Business (VOSB) on
GSA Schedule, and provides the highest caliber vendor-authorized
instruction at our training centers, online, or onsite.

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[hofar...@houseoffusion.com]

thanks for the info

ok, so then how would I do the copy from w2k3 to cf9 server

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[hofar...@houseoffusion.com]

Using cffile?

Russ Michaels
www.michaels.me.uk
cfmldeveloper.com
cflive.net
cfsearch.com

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[hofar...@houseoffusion.com]

>ok, so then how would I do the copy from w2k3 to cf9 server

You would use CFHTTP to grab the content from the other server, and then save it as a file on your CF9 server.

Personally I would do a separate CF app, scheduled in the CF administrator, that would periodically look for the file on the other server, and if it is there, grab it and download it.

Then when your aggregation app runs, it just has to worry about content on your server.

YMMV of course - I'm looking at it from the perspective of an application I worked on where the other server wasn't that reliable, and separating the "grab files from the other server" and "process files" helped troubleshooting tremendously.

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[hofar...@houseoffusion.com]

i am a bit confused, this is the first time I do this kind of request so bear with me.

I am trying to do the following:

i created a cf app on the source server (w2k3)

<cfquery name="Param" datasource="lib_datasql" >
SELECT proxloc from MainServer
</cfquery>
<cfset fname="#param.proxloc#\@conv_#dateformat(dateadd("d",-1,now()),'dd-mm-yyyy')#.txt">

<cfif FileExists("#fname#") >

(the above will check for the file and find it)

then i need to copy the file to the cf server and work with it, that's were you lost me.
<cfelse>
not found
</cfif>

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[hofar...@houseoffusion.com]

if you have direct access tot he server with the file then you would use
CFFILE to copy it.
If the file is only accessible over the web, then you can use CFHTTP to
grab the file content and save to your local server. You will of course not
get the raw file, only what is displayed in a browser.

Archive: http://www.houseoffusion.com/groups/cf-talk/message.cfm/messageid:358253

[hofar...@houseoffusion.com]

What is running on your w2k3 server? Is there a web server through which
the source/txt file is accessible? If so, sure, cfhttp can go out and grab
it over HTTP. Being a txt file, you wouldn't have to do anything fancy,
just point CFHTTP to the txt URL and then read the resulting file content
or even use the path and file attributes of CFHTTP to read and save the
file at the same time.

If there is no web server on the W2k3 server that holds the file, then
your options change.

If the two servers are on the same network, then you could run the CF
service as an account that has access to reach the file over UNC then just
use the UNC paths like you would normal paths in your cffile tag(s).

If they are not on the same network (and you canąt set them up that way),
then there are many ways that you could have the w2k3 server łsend˛ the
file to the other machine when it generates it. I believe you said there
is a visual fox pro app on the w2k3 box. If you control that app and can
change it, it is capable of POSTing a file to a URL (url being a page you
setup on your CF server to accept a multipart/form-data post to upload the
file).

If you canąt edit the VFP app, then you could install CURL on the W2k3 box
and still do the same thingŠ Have CURL post the file to a page you set up
on your CF server. Your CURL command would be a one liner that you could
either schedule with windows scheduler or you could set up a service on
the w2k3 box to monitor changes to the txt file and trigger the POST
automatically anytime it changes.

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[hofar...@houseoffusion.com]

As Russ mentions, *if* you have access to the file from the CF server (which you would need in order for the 'FileExists' function to work), then you could use a
<cffile action="copy"...... to get a copy of the file. If you don't have direct access to it, then you need to figure out "how" you can access it. If you can get to it
via http, then use a <cfhttp> tag. If you can get to it via FTP use a <cfftp> tag. You may need to alter your method for determining if the file exists though. If
you need to use HTTP or FTP, then you can always try to get the file and if you get an error, handle it appropriately (ex. the file isn't there, etc).

Regards,
Michael L Gueterman
Integrated Information Systems, Inc.
--

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