Using SharpZipLib to unzip specific files?

Question

I\'m trying to use SharpZipLib to pull specified files from a zip archive. All of the examples I\'ve seen always expect that you want to unzip the entire zip, and do somethi

Answer 1

Note - this answer suggests an alternative to SharpZipLib

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DotNetZip has a string indexer on the ZipFile class to make this really easy.

 using (ZipFile zip = ZipFile.Read(sourcePath)
 {
   zip["NameOfFileToUnzip.txt"].Extract();
 }

You don't need to fiddle with inputstreams and outputstreams and so on, just to extract a file. On the other hand if you want the stream, you can get it:

 using (ZipFile zip = ZipFile.Read(sourcePath)
 {
   Stream s = zip["NameOfFileToUnzip.txt"].OpenReader();
   // fiddle with stream here
 }

You can also do wildcard extractions.

 using (ZipFile zip = ZipFile.Read(sourcePath)
 {
     // extract all XML files in the archive
     zip.ExtractSelectedEntries("*.xml");
 }

There are overloads to specify overwrite/no-overwrite, different target directories, etc. You can also extract based on criteria other than the filename. For example, extract all files newer than January 15, 2009:

     // extract all files modified after 15 Jan 2009
     zip.ExtractSelectedEntries("mtime > 2009-01-15");

And you can combine criteria:

     // extract all files that are modified after 15 Jan 2009) AND  larger than 1mb
     zip.ExtractSelectedEntries("mtime > 2009-01-15 and size > 1mb");

     // extract all XML files that are modified after 15 Jan 2009) AND  larger than 1mb
     zip.ExtractSelectedEntries("name = *.xml and mtime > 2009-01-15 and size > 1mb");

You don't have to extract the files that you select. You can just select them and then make decisions on whether to extract or not.

    using (ZipFile zip1 = ZipFile.Read(ZipFileName))
    {
        var PhotoShopFiles = zip1.SelectEntries("*.psd");
        // the selection is just an ICollection
        foreach (ZipEntry e in PhotoShopFiles)
        {
            // examine metadata here, make decision on extraction
            e.Extract();
        }
    }