Question

Cursory Google search didn’t return anything simple enough to understand (i’m pretty new to functional programming).

if I have an array of files, how can i zip each file and then create a zip of all zipped files?

I have something like this so far:

let zip f = 
    f.zip //this is where I need the most direction

let zipAllAttachments f =
    f
    |> Seq.map zip   //do I need to create another function to create a single zip of all zips?

EDIT: this is what I have so far, but I’m getting some strange behavior. More to come once I figure out what the strange behavior IS exactly:

use zipfile = new ZipFile()
for fileObj in files do
    zipfile.AddFile(sprintf "%s%s" path  fileObj.Filename) |> ignore
    zipfile.Save("C:\\temp\\Compliance.zip")

UPDATE: I don’t think the “strange behavior” is related to the zip module. I appreciate all the help!

Answer 1

Are you trying to create an independent implementation of zip compression?

I’d use DotNetZip from http://dotnetzip.codeplex.com/ — it’s a single, managed code (C#) assembly. Using it from F# should be pretty much as simple as referencing the assembly from your project.

Usage is simple. For C#:

using (ZipFile zip = new ZipFile())
{
  // add this map file into the "images" directory in the zip archive
  zip.AddFile("c:\\images\\personal\\7440-N49th.png", "images");
  // add the report into a different directory in the archive
  zip.AddFile("c:\\Reports\\2008-Regional-Sales-Report.pdf", "files");
  zip.AddFile("ReadMe.txt");
  zip.Save("MyZipFile.zip");
}

If you want to zip a collection of zip files (why?), there’s a number of ways to do that with DotNetZip (you can, for instance, save your zip file to a stream, or add a stream to a zip file).

Hope this helps!

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Edited To Note: DotNetZip used to live at Codeplex. Codeplex has been shut down. The old archive is still [available at Codeplex][1]. It looks like the code has migrated to Github:

• https://github.com/DinoChiesa/DotNetZip. Looks to be the original author’s repo.
• https://github.com/haf/DotNetZip.Semverd. This looks to be the currently maintained version. It’s also packaged up an available via Nuget at https://www.nuget.org/packages/DotNetZip/

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