zipdetails

ZIPDETAILS(1)          Perl Programmers Reference Guide          ZIPDETAILS(1)

NAME
       zipdetails - display the internal structure of zip files

SYNOPSIS
           zipdetails [-v][--scan] zipfile.zip
           zipdetails -h
           zipdetails --version

DESCRIPTION
       Zipdetails displays information about the internal record structure of
       zip files. It is not concerned with displaying any details of the
       compressed data stored in the zip file.

       The program assumes prior understanding of the internal structure of a
       Zip file. You should have a copy of the Zip APPNOTE file at hand to
       help understand the output from this program ("SEE ALSO" for details).

   Default Behaviour
       By default the program expects to be given a well-formed zip file.  It
       will navigate the Zip file by first parsing the zip central directory
       at the end of the file.  If that is found, it will then walk through
       the zip records starting at the beginning of the file. Any badly formed
       zip data structures encountered are likely to terminate the program.

       If the program finds any structural problems with the zip file it will
       print a summary at the end of the output report. The set of error cases
       reported is very much a work in progress, so don't rely on this feature
       to find all the possible errors in a zip file. If you have suggestions
       for use-cases where this could be enhanced please consider creating an
       enhancement request (see "SUPPORT").

   Scan-Mode
       If you do have a potentially corrupt zip file, particulatly where the
       central directory at the end of the file is absent/incomplete, you can
       try usng the "--scan" option to search for zip records that are still
       present.

       When Scan-mode is enabled, the program will walk the zip file from the
       start blindly looking for the 4-byte signatures that preceed each of
       the zip data structures. If it finds any of the recognised signatures
       it will attempt to dump the associated zip record. For very large zip
       files, this operation can take a long time to run.

       Note that the 4-byte signatures used in zip files can sometimes match
       with random data stored in the zip file, so care is needed interpreting
       the results.

   OPTIONS
       -h   Display help

       --scan
            Walk the zip file loking for possible zip records. Can be error-
            prone.  See "Scan-Mode"

       -v   Enable Verbose mode. See "Verbose Output".

       --version
            Display version number of the program and exit.

   Default Output
       By default zipdetails will output the details of the zip file in three
       columns.

       Column 1
            This contains the offset from the start of the file in hex.

       Column 2
            This contains a textual description of the field.

       Column 3
            If the field contains a numeric value it will be displayed in hex.
            Zip stores most numbers in little-endian format - the value
            displayed will have the little-endian encoding removed.

            Next, is an optional description of what the value means.

   Verbose Output
       If the "-v" option is present, column 1 is expanded to include

       o    The offset from the start of the file in hex.

       o    The length of the field in hex.

       o    A hex dump of the bytes in field in the order they are stored in
            the zip file.

LIMITATIONS
       The following zip file features are not supported by this program:

       o    Multi-part archives.

       o    The strong encryption features defined in the "APPNOTE" document.

TODO
       Error handling is a work in progress. If the program encounters a
       problem reading a zip file it is likely to terminate with an unhelpful
       error message.

SUPPORT
       General feedback/questions/bug reports should be sent to
       <https://github.com/pmqs/IO-Compress/issues> (preferred) or
       <https://rt.cpan.org/Public/Dist/Display.html?Name=IO-Compress>.

SEE ALSO
       The primary reference for Zip files is the "APPNOTE" document available
       at <http://www.pkware.com/documents/casestudies/APPNOTE.TXT>.

       An alternative reference is the Info-Zip appnote. This is available
       from <ftp://ftp.info-zip.org/pub/infozip/doc/>

       The "zipinfo" program that comes with the info-zip distribution
       (<http://www.info-zip.org/>) can also display details of the structure
       of a zip file.

       See also Archive::Zip::SimpleZip, IO::Compress::Zip,
       IO::Uncompress::Unzip.

AUTHOR
       Paul Marquess pmqs@cpan.org.

COPYRIGHT
       Copyright (c) 2011-2021 Paul Marquess. All rights reserved.

       This program is free software; you can redistribute it and/or modify it
       under the same terms as Perl itself.

perl v5.34.0                      2025-07-25                     ZIPDETAILS(1)