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+++ b/README
@@ -1,10 +1,10 @@
Description
Clzip is a lossless data compressor with a user interface similar to the
-one of gzip or bzip2. Clzip decompresses almost as fast as gzip and
-compresses more than bzip2, which makes it well suited for software
-distribution and data archiving. Clzip is a clean implementation of the
-LZMA algorithm.
+one of gzip or bzip2. Clzip decompresses almost as fast as gzip,
+compresses most files more than bzip2, and is better than both from a
+data recovery perspective. Clzip is a clean implementation of the LZMA
+algorithm.
Clzip uses the lzip file format; the files produced by clzip are fully
compatible with lzip-1.4 or newer, and can be rescued with lziprecover.
@@ -12,17 +12,23 @@ Clzip is in fact a C language version of lzip, intended for embedded
devices or systems lacking a C++ compiler.
The lzip file format is designed for long-term data archiving and
-provides very safe integrity checking. The member trailer stores the
-32-bit CRC of the original data, the size of the original data and the
-size of the member. These values, together with the value remaining in
-the range decoder and the end-of-stream marker, provide a 4 factor
-integrity checking which guarantees that the decompressed version of the
-data is identical to the original. This guards against corruption of the
-compressed data, and against undetected bugs in clzip (hopefully very
-unlikely). The chances of data corruption going undetected are
-microscopic. Be aware, though, that the check occurs upon decompression,
-so it can only tell you that something is wrong. It can't help you
-recover the original uncompressed data.
+provides very safe integrity checking. It is as simple as possible (but
+not simpler), 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.
+Additionally lzip is copylefted, which guarantees that it will remain
+free forever.
+
+The member trailer stores the 32-bit CRC of the original data, the size
+of the original data and the size of the member. These values, together
+with the value remaining in the range decoder and the end-of-stream
+marker, provide a 4 factor integrity checking which guarantees that the
+decompressed version of the data is identical to the original. This
+guards against corruption of the compressed data, and against undetected
+bugs in clzip (hopefully very unlikely). The chances of data corruption
+going undetected are microscopic. Be aware, though, that the check
+occurs upon decompression, so it can only tell you that something is
+wrong. It can't help you recover the original uncompressed data.
If you ever need to recover data from a damaged lzip file, try the
lziprecover program. Lziprecover makes lzip files resistant to bit-flip
@@ -31,15 +37,26 @@ recovery capabilities, including error-checked merging of damaged copies
of a file.
Clzip uses the same well-defined exit status values used by lzip and
-bzip2, which makes it safer when used in pipes or scripts than
-compressors returning ambiguous warning values, like gzip.
+bzip2, which makes it safer than compressors returning ambiguous warning
+values (like gzip) when it is used as a back end for tar or zutils.
-Clzip replaces every file given in the command line with a compressed
-version of itself, with the name "original_name.lz". Each compressed
-file has the same modification date, permissions, and, when possible,
-ownership as the corresponding original, so that these properties can be
-correctly restored at decompression time. Clzip is able to read from some
-types of non regular files if the "--stdout" option is specified.
+When compressing, clzip replaces every file given in the command line
+with a compressed version of itself, with the name "original_name.lz".
+When decompressing, clzip attempts to guess the name for the decompressed
+file from that of the compressed file as follows:
+
+filename.lz becomes filename
+filename.tlz becomes filename.tar
+anyothername becomes anyothername.out
+
+(De)compressing a file is much like copying or moving it; therefore clzip
+preserves the access and modification dates, permissions, and, when
+possible, ownership of the file just as "cp -p" does. (If the user ID or
+the group ID can't be duplicated, the file permission bits S_ISUID and
+S_ISGID are cleared).
+
+Clzip is able to read from some types of non regular files if the
+"--stdout" option is specified.
If no file names are specified, clzip compresses (or decompresses) from
standard input to standard output. In this case, clzip will decline to
@@ -81,7 +98,7 @@ range encoding), Igor Pavlov (for putting all the above together in
LZMA), and Julian Seward (for bzip2's CLI).
-Copyright (C) 2010, 2011, 2012, 2013 Antonio Diaz Diaz.
+Copyright (C) 2010, 2011, 2012, 2013, 2014 Antonio Diaz Diaz.
This file is free documentation: you have unlimited permission to copy,
distribute and modify it.