Use 7-zip to extract zip files with file paths greater than 255 characters

The file compression program 7-zip can help you extract data from zip container files which have folder structures which will result in file paths longer than the 255 character limit for Windows Explorer.

While the extraction tool for Windows Explorer will not extract files with paths longer than this limit and will prompt you to skip over them, 7-zip does not have this limitation.

See this comparison of files extracted from the same source zip file with email data from the publicly available Enron data set.

The set extracted with Windows Explorer contains only 7629 files, while the set extracted with 7-zip contains 9546 files, the complete total from the original file.

In this directory we can see the gaps in the numbered files in the set extracted with Windows Explorer for the longer file names:

7-zip will also complete the extraction in a fraction of the time required by Windows Explorer.

Recombining split files

Data may be transferred in split files, which will commonly have the extension .bin or simply .001, .002, .003, etc.. These files can be re-combined into the .RAR format, a common archive format similar to .zip. You can use a command in DOS to recombine these binary files into a single .RAR file that can be opened.

copy /b splitfile1.bin + spiltfile2.bin "2019LItSupport.rar"

Two files, 'splitfile1.bin' and 'splitfile2.bin' from separate discs or downloads, become a single rar file that can be opened in WinRAR or 7-zip.

7-zip also contains a utility to re-combine split files but WinRAR does not.

WinZip error - central and local directory mismatch

When opening a compressed file with the extension zip using WinZip you may encounter the following error:

The full error will read in detailed diagnostics, "Central and local directory mismatch for file "acmeco/" (compressed size - local: 4294967295 central: 0). Severe Error: Local and central compressed size values don't match.".

A zip file is structured to have file headers preceding each file entry, followed at the end by a central directory. The central directory lists the file entries and associated metadata, keeping track of each file's location. Each file header must be matched by a central directory header. The central directory allows for a list of the files to be generated very quickly after the compressed file is opened, without the need for the software to read each actual file.

I was able to get around this problem and successfully unzip by opening the zip file in Windows Explorer rather than WinZip. Simply right click on the file and choose the option to open it with Windows Explorer.

Hard to say what's going on but it looks like Windows Explorer can keep track of the file header information in a way WinZip 16.5 can't.