How to prevent Windows from throwing an error everytime it tries to copy a file named with illegal characters?

Question

I'm extracting a medium sized ZIP file which contains thousands of tiny files with different names. Some of these files have names which include illegal character like ":". This causes Windows to be rather unhappy when it tries to extract them and copy them to the destination folder.

It throws Error 0x80070057. Some sources online calim this is due to a lack of disk space, but that is definitely not true in my case. This error is most liekly due to the file containing illegal caharcters in its name, as the other files copy with no problems.

Windows then asks me to Try Again or Skip, once I select try again, it simply replaces any illegal characters with "_" which fixes the porblem just fine.

My question is how do I prevent Windows from asking me thousands of times? I tried checking the Do this for all current items checkbox, but that has no effect.

This question is completely different from this one. One because I am not using 7Zip and instead am using Windows built in extracter. Two, because that question is about resolving name conflicts and this question is about removing illegal characters from file names.

Answer 1

.Net prvides several classes within the System.IO.Compression namespace. They provide varous methods that give you a higher level of control over creation, modification, and extraction.

To convert any illegai filenames to legal filenames during extration, the methods/properties used will be:

• ZipFile.OpenRead()
  • to open the zip file as as ZipArchvie
• ZipArchive.Entries
  • to obtain a list of the individual entries in teh file
• ZipFileExtensions.ExtractToFile()
  • to extract each entry with the opportunity to modify the name of the extreacted file

---

Edit: PowerShell code to correct illegal filenames during extraction

Since you found a Python solution that worked for you, I took my time playing with these classes, as they're new to me. But for the sake of the curious and future readers, here's straight PowerShell/.net code.

This code opens a .zip file as a ZipArchive and replaces any illegal characters in the Name/FullName of each ZipArchiveEntry with the underscore(_) character prior to extraction.

Input is hard-coded here to keep the focus on the file manipulation, but the code can serve as the basis for a function or context menu entry.

###   User Input   ###
$ZipPath        = 'C:\Users\Whoever\Wherever\Illegal.zip'   ###   Path to .zip file
$ExtractPath    = 'C:\Users\Whoever\NonExisting'            ###   Path of target directory

###   Load required assemblies
Add-Type -AssemblyName System.IO.Compression
Add-Type -AssemblyName System.IO.Compression.FileSystem

###   Construct regex character class to match illegal characters
$IllegalChars   = '[{0}]' -f ( -join [IO.Path]::GetInvalidFileNameChars().ForEach{[Regex]::Escape($_)})

###   Create target directory if it doesn't exist
If (!(Test-Path $ExtractPath))
{
    mkdir $ExtractPath -Force | out-null
}

###   Ensure ExtractPath is fully-qualified for subsequent operations
$ExtractPath    = [IO.Path]::GetFullPath($ExtractPath)

$Archive        = [IO.Compression.ZipFile]::OpenRead($ZipPath)

$Archive.Entries | ForEach{
    If ($_.Name -eq $_.FullName)   ###   no subdirectory
    {
        [IO.Compression.ZipFileExtensions]::ExtractToFile($_, (Join-Path $ExtractPath ($_.Name -replace ($IllegalChars,'_'))))
    }
    Else                           ###   subdirectory 
    {
        $ChildPath   = $_.FullName.Split('/') -replace ($IllegalChars,'_') -join [io.Path]::DirectorySeparatorChar
        $subFolder   = Split-Path $ChildPath
        If (!(Test-Path $subFolder))
        {
            mkdir $subFolder -Force | out-null
        }
        [IO.Compression.ZipFileExtensions]::ExtractToFile($_, (Join-Path $ExtractPath $ChildPath))
    }
}