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Diffstat (limited to 'doc/clzip.info')
| -rw-r--r-- | doc/clzip.info | 54 |
1 files changed, 31 insertions, 23 deletions
diff --git a/doc/clzip.info b/doc/clzip.info index ccec058..41723f3 100644 --- a/doc/clzip.info +++ b/doc/clzip.info @@ -12,7 +12,7 @@ File: clzip.info, Node: Top, Next: Introduction, Up: (dir) Clzip Manual ************ -This manual is for Clzip (version 1.4, 18 February 2013). +This manual is for Clzip (version 1.5-pre1, 13 May 2013). * Menu: @@ -42,6 +42,10 @@ 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++ @@ -96,20 +100,16 @@ filename.tlz becomes filename.tar anyothername becomes anyothername.out 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. +trailer 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. File: clzip.info, Node: Algorithm, Next: Invoking Clzip, Prev: Introduction, Up: Top @@ -326,6 +326,12 @@ E exabyte (10^18) | Ei exbibyte (2^60) Z zettabyte (10^21) | Zi zebibyte (2^70) Y yottabyte (10^24) | Yi yobibyte (2^80) + + 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. + File: clzip.info, Node: File Format, Next: Examples, Prev: Invoking Clzip, Up: Top @@ -378,6 +384,7 @@ additional information before, between, or after them. 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. `Lzma stream' @@ -392,8 +399,9 @@ additional information before, between, or after them. `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. + acts as a distributed index, allows the verification of stream + integrity, and facilitates safe recovery of undamaged members from + multi-member files. @@ -509,12 +517,12 @@ Concept Index Tag Table: Node: Top226 Node: Introduction920 -Node: Algorithm4755 -Node: Invoking Clzip7279 -Node: File Format12551 -Node: Examples14860 -Node: Problems16821 -Node: Concept Index17347 +Node: Algorithm4811 +Node: Invoking Clzip7335 +Node: File Format12847 +Node: Examples15277 +Node: Problems17238 +Node: Concept Index17764 End Tag Table |