Compare 2 files with different names (checksum?)

ruby-talk
1

Hey all

I've been using File.compare to see if two files are the same, but now i
have the case where one is a renamed copy of the other. I'd like to
treat these two as the same in this case. Can anyone suggest a test
that doesn't care about names?

The files that have been renamed are xml (ie text format) if that makes
life easier but a solution that works with binaries as well would be
ideal.

I've been trying to google checksums in ruby but haven't seen a useful
example, maybe i was just being blind. Will a checksum ignore the name
of the file?

thanks
max

···

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2

google for Ruby digest. A SHA1 hash is a good alternative.

require 'digest/sha1'

def contents_equal?(path_to_file_1, path_to_file_2)
   Digest::SHA1.file(path_to_file_1).hexdigest ==
Digest::SHA1.file(path_to_file_2).hexdigest
end

···

On Fri, Sep 18, 2009 at 12:05 PM, Max Williams <toastkid.williams@gmail.com> wrote:

Hey all

I've been using File.compare to see if two files are the same, but now i
have the case where one is a renamed copy of the other. I'd like to
treat these two as the same in this case. Can anyone suggest a test
that doesn't care about names?

The files that have been renamed are xml (ie text format) if that makes
life easier but a solution that works with binaries as well would be
ideal.

I've been trying to google checksums in ruby but haven't seen a useful
example, maybe i was just being blind. Will a checksum ignore the name
of the file?

--
Rick DeNatale

Blog: http://talklikeaduck.denhaven2.com/
Twitter: http://twitter.com/RickDeNatale
WWR: http://www.workingwithrails.com/person/9021-rick-denatale
LinkedIn: http://www.linkedin.com/in/rickdenatale

3

Max Williams wrote:

Hey all

I've been using File.compare to see if two files are the same, but now i
have the case where one is a renamed copy of the other. I'd like to
treat these two as the same in this case. Can anyone suggest a test
that doesn't care about names?

The files that have been renamed are xml (ie text format) if that makes
life easier but a solution that works with binaries as well would be
ideal.

I've been trying to google checksums in ruby but haven't seen a useful
example, maybe i was just being blind. Will a checksum ignore the name
of the file?

thanks
max

Hmm? File.compare does not care about names, the content of the files is
compared.

require 'ftools'
File.compare(path_to_file_1, path_to_file_2)

Works fine for me (Ruby 1.8.6, WinXP). Are there issues I'm not aware
of?

Kind regards,

Siep

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4

that's great, thanks Rick!
max

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5

Hmmm (tests) - no Siep, you're right. Looks like the two files i
thought were the same weren't after all. Which is a problem, since the
second one is supposed to be a renamed copy of the first. Looks like i
need to go back a step here. :confused:

thanks
max

···

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