How to handle empty zip files with C# ZipFile

Question

I have a program in C# which unzip files with ZipFile. It is normally working but if the zip file is empty it fails.

The code:

System.IO.Compression.ZipFile.ExtractToDirectory(fileName, dirName);

Is there a way to detect if the zip file is empty and delete it? (I do not want to delete the file if it fails and it is not empty.)

What's "empty zip file" mean? Describe empty? It's either a file or it's not. — Liam, Jan 15 '19 at 14:54
Catch the resulting exception? Verify it first by checking the length? 0 bytes is invalid, while a zipfile with no zipped files inside it will have some sort of minimum length (don't know what it would be). — Jeroen Mostert, Jan 15 '19 at 14:55
Docs say that you will get an exception in that case, just handle it. [DOCS](https://learn.microsoft.com/en-us/dotnet/api/system.io.compression.zipfile.extracttodirectory?view=netframework-4.7.2) — Marian Simonca, Jan 15 '19 at 14:56
What do you mean by *** if the zip file is empty it fails*** — preciousbetine, Jan 15 '19 at 14:57
With "empty zip file" I mean a zip file with no files and it is 0 bytes. — Erik Dahlen, Jan 15 '19 at 14:57
You can filter by `catch(ExceptionWhenIsEmtpy)` and do whatever you need to do when that happens.. — Nekeniehl, Jan 15 '19 at 14:59
If using ’ZipArchive’, check whether the count of the ’Entries’ property is zero. — silkfire, Jan 15 '19 at 15:02

score 1 · Accepted Answer · answered Jan 15 '19 at 15:04

1

You can try this:

if (!string.IsNullOrEmpty(dirName) && Directory.Exists(dirName))
{
    try
    {
        System.IO.Compression.ZipFile.ExtractToDirectory(fileName, dirName);
    }
    catch (ArgumentException ex)
    {
        // file is empty (as we already checked for directory)
        File.Delete(fileName);
    }


    // OR

    if (new FileInfo(fileName).Length == 0)
    {
        // empty
        File.Delete(fileName);
    }
    else
    {
        System.IO.Compression.ZipFile.ExtractToDirectory(fileName, dirName);
    }
}

How to check if file is empty

answered Jan 15 '19 at 15:04

Marian Simonca

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You could/should combine these two, not `// OR` – bommelding Jan 15 '19 at 15:13
I only used the second one, because I do not want to render an exception. It works just fine in my case. – Erik Dahlen Jan 15 '19 at 15:30

How to handle empty zip files with C# ZipFile

1 Answers1