1ZIPDETAILS(1)         User Contributed Perl Documentation        ZIPDETAILS(1)
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NAME

6       zipdetails - display the internal structure of zip files
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SYNOPSIS

9           zipdetails [-v][--scan] zipfile.zip
10           zipdetails -h
11           zipdetails --version
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DESCRIPTION

14       Zipdetails displays information about the internal record structure of
15       zip files. It is not concerned with displaying any details of the
16       compressed data stored in the zip file.
17
18       The program assumes prior understanding of the internal structure of a
19       Zip file. You should have a copy of the Zip APPNOTE file at hand to
20       help understand the output from this program ("SEE ALSO" for details).
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22   Default Behaviour
23       By default the program expects to be given a well-formed zip file.  It
24       will navigate the Zip file by first parsing the zip central directory
25       at the end of the file.  If that is found, it will then walk through
26       the zip records starting at the beginning of the file. Any badly formed
27       zip data structures encountered are likely to terminate the program.
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29       If the program finds any structural problems with the zip file it will
30       print a summary at the end of the output report. The set of error cases
31       reported is very much a work in progress, so don't rely on this feature
32       to find all the possible errors in a zip file. If you have suggestions
33       for use-cases where this could be enhanced please consider creating an
34       enhancement request (see "SUPPORT").
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36   Scan-Mode
37       If you do have a potentially corrupt zip file, particulatly where the
38       central directory at the end of the file is absent/incomplete, you can
39       try usng the "--scan" option to search for zip records that are still
40       present.
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42       When Scan-mode is enabled, the program will walk the zip file from the
43       start blindly looking for the 4-byte signatures that preceed each of
44       the zip data structures. If it finds any of the recognised signatures
45       it will attempt to dump the associated zip record. For very large zip
46       files, this operation can take a long time to run.
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48       Note that the 4-byte signatures used in zip files can sometimes match
49       with random data stored in the zip file, so care is needed interpreting
50       the results.
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52   OPTIONS
53       -h   Display help
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55       --scan
56            Walk the zip file loking for possible zip records. Can be error-
57            prone.  See "Scan-Mode"
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59       -v   Enable Verbose mode. See "Verbose Output".
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61       --version
62            Display version number of the program and exit.
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64   Default Output
65       By default zipdetails will output the details of the zip file in three
66       columns.
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68       Column 1
69            This contains the offset from the start of the file in hex.
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71       Column 2
72            This contains a textual description of the field.
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74       Column 3
75            If the field contains a numeric value it will be displayed in hex.
76            Zip stores most numbers in little-endian format - the value
77            displayed will have the little-endian encoding removed.
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79            Next, is an optional description of what the value means.
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81   Verbose Output
82       If the "-v" option is present, column 1 is expanded to include
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84       •    The offset from the start of the file in hex.
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86       •    The length of the field in hex.
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88       •    A hex dump of the bytes in field in the order they are stored in
89            the zip file.
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LIMITATIONS

92       The following zip file features are not supported by this program:
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94       •    Multi-part archives.
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96       •    The strong encryption features defined in the "APPNOTE" document.
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TODO

99       Error handling is a work in progress. If the program encounters a
100       problem reading a zip file it is likely to terminate with an unhelpful
101       error message.
102

SUPPORT

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

109       The primary reference for Zip files is the "APPNOTE" document available
110       at <http://www.pkware.com/documents/casestudies/APPNOTE.TXT>.
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112       An alternative reference is the Info-Zip appnote. This is available
113       from <ftp://ftp.info-zip.org/pub/infozip/doc/>
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115       The "zipinfo" program that comes with the info-zip distribution
116       (<http://www.info-zip.org/>) can also display details of the structure
117       of a zip file.
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119       See also Archive::Zip::SimpleZip, IO::Compress::Zip,
120       IO::Uncompress::Unzip.
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AUTHOR

123       Paul Marquess pmqs@cpan.org.
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126       Copyright (c) 2011-2021 Paul Marquess. All rights reserved.
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128       This program is free software; you can redistribute it and/or modify it
129       under the same terms as Perl itself.
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133perl v5.32.1                      2021-03-01                     ZIPDETAILS(1)
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