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author | Daniel Baumann <mail@daniel-baumann.ch> | 2015-11-06 11:37:40 +0000 |
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committer | Daniel Baumann <mail@daniel-baumann.ch> | 2015-11-06 11:37:40 +0000 |
commit | c33e1de813af248d4249725ac859dd3a26393704 (patch) | |
tree | 2a277fd093d46566d11b96d68ee4b9ba950e96be /doc/clzip.texinfo | |
parent | Adding upstream version 1.4. (diff) | |
download | clzip-c33e1de813af248d4249725ac859dd3a26393704.tar.xz clzip-c33e1de813af248d4249725ac859dd3a26393704.zip |
Adding upstream version 1.5~pre1.upstream/1.5_pre1
Signed-off-by: Daniel Baumann <mail@daniel-baumann.ch>
Diffstat (limited to 'doc/clzip.texinfo')
-rw-r--r-- | doc/clzip.texinfo | 43 |
1 files changed, 25 insertions, 18 deletions
diff --git a/doc/clzip.texinfo b/doc/clzip.texinfo index 1d0479f..e372d60 100644 --- a/doc/clzip.texinfo +++ b/doc/clzip.texinfo @@ -6,8 +6,8 @@ @finalout @c %**end of header -@set UPDATED 18 February 2013 -@set VERSION 1.4 +@set UPDATED 13 May 2013 +@set VERSION 1.5-pre1 @dircategory Data Compression @direntry @@ -61,6 +61,10 @@ gzip or bzip2. Clzip decompresses almost as fast as gzip and compresses better than bzip2, which makes it well suited for software distribution and data archiving. +Clzip uses the same well-defined exit status values used by bzip2, which +makes it safer when used in pipes or scripts than compressors returning +ambiguous warning values, like gzip. + Clzip uses the lzip file format; the files produced by clzip are fully compatible with lzip-1.4 or newer. Clzip is in fact a C language version of lzip, intended for embedded devices or systems lacking a C++ @@ -117,20 +121,16 @@ file from that of the compressed file as follows: @end multitable As a self-check for your protection, clzip stores in the member trailer -the 32-bit CRC of the original data and the size of the original data, -to make sure 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, less than one -chance in 4000 million for each member processed. 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. - -Return values: 0 for a normal exit, 1 for environmental problems (file -not found, invalid flags, I/O errors, etc), 2 to indicate a corrupt or -invalid input file, 3 for an internal consistency error (eg, bug) which -caused clzip to panic. +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 very safe 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. @node Algorithm @@ -349,6 +349,12 @@ Table of SI and binary prefixes (unit multipliers): @item Y @tab yottabyte (10^24) @tab | @tab Yi @tab yobibyte (2^80) @end multitable +@sp 1 +Exit status: 0 for a normal exit, 1 for environmental problems (file not +found, invalid flags, I/O errors, etc), 2 to indicate a corrupt or +invalid input file, 3 for an internal consistency error (eg, bug) which +caused clzip to panic. + @node File Format @chapter File Format @@ -404,6 +410,7 @@ wedges between 0 and 7. The size of a wedge is (base_size / 16).@* Bits 4-0 contain the base 2 logarithm of the base size (12 to 29).@* Bits 7-5 contain the number of wedges (0 to 7) to substract from the base size to obtain the dictionary size.@* +Example: 0xD3 = (2^19 - 6 * 2^15) = (512KiB - 6 * 32KiB) = 320KiB@* Valid values for dictionary size range from 4KiB to 512MiB. @item Lzma stream @@ -418,8 +425,8 @@ Size of the uncompressed original data. @item Member size (8 bytes) Total size of the member, including header and trailer. This field acts -as a distributed index, and facilitates safe recovery of undamaged -members from multi-member files. +as a distributed index, allows the verification of stream integrity, and +facilitates safe recovery of undamaged members from multi-member files. @end table |