2

What I need to do, at the command line, is:

  1. Extract the contents of a a ZIP archive.
  2. Change an arbitrary number of the extracted files.
  3. Repeat step 1, but because it is a huge archive, only extract the archived copies of the files changed in step 2 which is much faster.

Ideally the extraction in step 3 would do something like a checksum on the files on disk and only extract those where the file in the archive has a different checksum. Or maybe compare the date changed stamp on the disk file.

At the minute I use pkzipc.exe which is the command-line version of PkZip. I can't see a way to do it with this though. You can extract files from the archive that are newer than the disk files, but what I want is the opposite of that in a sense.

0

I've been looking for a program that would use the CRC32 in the zip file to know if a file had changed, but if all you care for is a date/time stamp and size, TreeComp could work for you.

0

Hmm, maybe I'm misunderstanding what you're trying to do, but why don't you just keep a second copy of the files that you're going to change (in step 2)?

Is there any particular reason you need to re-extract?

7-Zip has a command-line version that I'd suggest looking at regardless, I prefer it over all the other windows archiving tools I've used.

0

You can make a small Powershell function:

Function MyZip($Source,$Destination){
  "MD5 Hash: $((certutil -hashFile "$Source")[1])"
  Expand-Archive "$Path" "$Destination"
}

It will first show the MD5 hash of the zip file, then it will expand the archive into destination. To call:

MyZip("Source.zip","C:\Destination\")

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