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Merging upstream version 1.6.

Signed-off-by: Daniel Baumann <daniel@debian.org>
This commit is contained in:
Daniel Baumann 2025-02-24 04:14:20 +01:00
parent ee79238874
commit d41db2478f
Signed by: daniel
GPG key ID: FBB4F0E80A80222F
22 changed files with 748 additions and 400 deletions

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@ -6,8 +6,8 @@
@finalout
@c %**end of header
@set UPDATED 14 May 2016
@set VERSION 1.5
@set UPDATED 12 April 2017
@set VERSION 1.6
@dircategory Data Compression
@direntry
@ -48,7 +48,7 @@ This manual is for Plzip (version @value{VERSION}, @value{UPDATED}).
@end menu
@sp 1
Copyright @copyright{} 2009-2016 Antonio Diaz Diaz.
Copyright @copyright{} 2009-2017 Antonio Diaz Diaz.
This manual is free documentation: you have unlimited permission
to copy, distribute and modify it.
@ -90,10 +90,10 @@ including error-checked merging of damaged copies of a file.
@item
The lzip format is as simple as possible (but not simpler). The lzip
manual provides the code of a simple decompressor along with a detailed
explanation of how it works, so that with the only help of the lzip
manual it would be possible for a digital archaeologist to extract the
data from a lzip file long after quantum computers eventually render
manual provides the source code of a simple decompressor along with a
detailed explanation of how it works, so that with the only help of the
lzip manual it would be possible for a digital archaeologist to extract
the data from a lzip file long after quantum computers eventually render
LZMA obsolete.
@item
@ -146,6 +146,10 @@ or more compressed files. The result is the concatenation of the
corresponding uncompressed files. Integrity testing of concatenated
compressed files is also supported.
LANGUAGE NOTE: Uncompressed = not compressed = plain data; it may never
have been compressed. Decompressed is used to refer to data which have
undergone the process of decompression.
@node Invoking plzip
@chapter Invoking plzip
@ -220,6 +224,20 @@ Force re-compression of files whose name already has the @samp{.lz} or
@itemx --keep
Keep (don't delete) input files during compression or decompression.
@item -l
@itemx --list
Print the uncompressed size, compressed size and percentage saved of the
specified file(s). Trailing data are ignored. The values produced are
correct even for multimember files. If more than one file is given, a
final line containing the cumulative sizes is printed. With @samp{-v},
the dictionary size, the number of members in the file, and the amount
of trailing data (if any) are also printed. With @samp{-vv}, the
positions and sizes of each member in multimember files are also
printed. @samp{-lq} can be used to verify quickly (without
decompressing) the structural integrity of the specified files. (Use
@samp{--test} to verify the data integrity). @samp{-alq} additionally
verifies that none of the specified files contain trailing data.
@item -m @var{bytes}
@itemx --match-length=@var{bytes}
Set the match length limit in bytes. After a match this long is found,
@ -267,8 +285,9 @@ is affected at compression time by the choice of dictionary size limit.
Check integrity of the specified file(s), but don't decompress them.
This really performs a trial decompression and throws away the result.
Use it together with @samp{-v} to see information about the file(s). If
a file fails the test, plzip may be unable to check the rest of the
files.
a file does not exist, can't be opened, or is a terminal, plzip
continues checking the rest of the files. If a file fails the test,
plzip may be unable to check the rest of the files.
@item -v
@itemx --verbose
@ -469,9 +488,6 @@ times the data size. Default is 136 MiB.
For decompression of a regular (seekable) file to another regular file,
or for testing of a regular file; the dictionary size.
(Note that regular files with more than 1024 bytes of trailing data are
treated as non-seekable).
@item
For testing of a non-seekable file or of standard input; the dictionary
size plus up to 5 MiB.
@ -526,20 +542,24 @@ data size for each level:
@chapter Extra data appended to the file
@cindex trailing data
Sometimes extra data is found appended to a lzip file after the last
Sometimes extra data are found appended to a lzip file after the last
member. Such trailing data may be:
@itemize @bullet
@item
Padding added to make the file size a multiple of some block size, for
example when writing to a tape.
@item
Garbage added by some not totally successful copy operation.
example when writing to a tape. It is safe to append any amount of
padding zero bytes to a lzip file.
@item
Useful data added by the user; a cryptographically secure hash, a
description of file contents, etc.
description of file contents, etc. It is safe to append any amount of
text to a lzip file as long as the text does not begin with the string
"LZIP", and does not contain any zero bytes (null characters). Nonzero
bytes and zero bytes can't be safely mixed in trailing data.
@item
Garbage added by some not totally successful copy operation.
@item
Malicious data added to the file in order to make its total size and
@ -554,8 +574,12 @@ integrity information itself. Therefore it can be considered to be below
the noise level.
@end itemize
Trailing data are in no way part of the lzip file format, but tools
reading lzip files are expected to behave as correctly and usefully as
possible in the presence of trailing data.
Trailing data can be safely ignored in most cases. In some cases, like
that of user-added data, it is expected to be ignored. In those cases
that of user-added data, they are expected to be ignored. In those cases
where a file containing trailing data must be rejected, the option
@samp{--trailing-error} can be used. @xref{--trailing-error}.
@ -620,8 +644,8 @@ plzip -c /dev/sdc > file.lz
@sp 1
@anchor{concat-example}
@noindent
Example 6: The right way of concatenating compressed files.
@xref{Trailing data}.
Example 6: The right way of concatenating the decompressed output of two
or more compressed files. @xref{Trailing data}.
@example
Don't do this