Comparing Files with only Date Time Stamp Difference

  • Thread starter Thread starter rm
  • Start date Start date
R

rm

We have this strange situation:

We use a development tool that is maybe not so reliable when executing
incremental compilations. The fact that we use the tool is not going
away anytime soon. So the following is a replica of our real live
situation.

We have an app with a release package composed of 4 binary files. For
example:

ui.exe
db.dll
commo.dll
busrule.dll

Each time a change is made to any part of the source code we execute a
full recompile and reproduce all 4 binary files.

The key to the problem I am presenting is that we need to execute a
per compile - file by file compare to determine which files actually
had a changes vs comparing the date, time and or version stamp.

For example - if we make a change in ui.dll and commo.dll then execute
a recompile all 4 images will have a new date time stamp. However I
need an automated way to compare the previous copies of the images vs.
the new copies and programmatically indicate that only the two images
have changed.

One suggestion so far is a CRC check.

We are using a tool - BeyondCompare. In the documentation the company
that supplied the tool indicates that a CRC check is *likely* to
indicate a change. I have been advised that the odds are very high.
However, I need a 100 percent certain method.

May I have a suggestion please?
 
You could also keep a copy of those files and do a full comparision.

Else try http://en.wikipedia.org/wiki/Cryptographic_hash_function

Not sure which kind of CRC they are using but note also that even though
some could produce collisions this is so unlikely that you are pretty safe
(ie do you need 100 % rather than 99.9999999 % ?). Too bad their likelyness
is not quantified...
 
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