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I need to compare a large number of files (100K+), I cannot add crazy any applications to the server I am working on, so I am using COMP.

It seems to be ok for the job, but I cannot find any documentation on what it is actually comparing.

Does it only compare file size? or Is it looking a bit deeper?

Are there any other built-in tools I should be looking at?

EDIT: I've just realised that COMP doesn't do sub directories. So, I'm really now open to more creative solutions.

EDIT: CLARIFICATION I only have remote READ ONLY (I am Admin on the machine, but we are under strict instructions not to write anything to the machine) access to the machine, so I cannot add any utilities. That's what I meant by crazy, I can only use what comes with Windows2K3

EDIT: WHY: We have just taken hold of a website running on two load balanced web servers. But the machines are NOT identical and I am trying to find out what the differences are, so if this is a completely dumb idea, please help me out and tell me what I am supposed to be doing. I'm a web developer and do not usually do stuff like this.

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What are you trying to compare?? File size, number of lines, file content (and do you want the difference or just a true/false)?? – Sam Aug 20 '09 at 10:02
It seems you're 'diffing directories, not files. What purpose could diffing 100k files possibly serve, anyhow ? – Rook Aug 20 '09 at 10:17
define "crazy applications", as there are quite a few good applications that should solve your problem easily, even freeware. – FrankS Aug 20 '09 at 10:36
yes you are right I am comparing files in directories ... – in.spite Aug 20 '09 at 10:53
does this maybe belong in serverfault? – Nathan Fellman Aug 20 '09 at 11:41
up vote 5 down vote accepted

Does it only compare file size?

From the website you link to , it 'displays the individual characters that differ.'

If the files are of different sizes, then by default no further comparison is needed or made. If the files are the same size, it compares byte by byte and displays the first few changes.

You can also use fc /b which doesn't have the annoying 'compare more files prompt at the end'.

But, if I was doing this, I would use Beyond Compare. This can be run on the server, but does not have to be installed on the server, ie you can create a portable version that will run from a cd /usb stick or from a network location. (And obviously you can also install to a local machine and access the files across the network.)

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Should add, that beyond compare could also be used if ALL the files are accessible via ftp. – sgmoore Aug 20 '09 at 11:31
I think Beyond Compare is just the tool I'm after, I might be able to make a case for its use. – in.spite Aug 20 '09 at 12:49

You are going to have difficulty comparing that start of data without being able to use an extra tool.

How large is the content that you are trying to compare? If those 100K files are only 10Kbyte long on average then that is on a Gb of stuff so it might be practical to copy the whole lot from both machines to your local system using your read-only access and compare them there with a more useful tool. Of course if the files are much bigger on average (images at 100K+ each or, even worse, videos) then this will of course be completely impractical...

Could you tell us more about you "read only" access? The following assumes that you have access to a locked-down user account via RDC.

You should find that you have write access to your user profile, at least to the temp directory as identified by ECHO %TEMP%. If your account is not locked down such that it can't execute programs outside a whitelist of directories you could try drop a portable (no install needed) tool in there and running it. I would recommend asking the server admins first though, as they might well be unhappy to find this has happened without their knowledge!

Alternatively, you could just ask the server admins if they could install a decent file compare utility like WinMerge where you can run it. Or have you already tried that route?

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COMP compares the contents of files, byte by byte.

But there are plenty of better tools for comparing directories. WinDiff and KDiff3 are the first that spring to mind.

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