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Diffstat (limited to 'doc/lziprecover.texi')
| -rw-r--r-- | doc/lziprecover.texi | 45 |
1 files changed, 30 insertions, 15 deletions
diff --git a/doc/lziprecover.texi b/doc/lziprecover.texi index 85f0385..2bcaa0a 100644 --- a/doc/lziprecover.texi +++ b/doc/lziprecover.texi @@ -6,8 +6,8 @@ @finalout @c %**end of header -@set UPDATED 21 January 2015 -@set VERSION 1.17-rc1 +@set UPDATED 8 April 2015 +@set VERSION 1.17-rc2 @dircategory Data Compression @direntry @@ -311,10 +311,11 @@ data stream, even if it is just one altered bit, the original data can't be recovered. If you used bzip2, and if the file is large enough to contain more than -one compressed data block (usually larger than 900 kB), and if no block -is damaged in both files, then the data can be manually recovered by -splitting the files with bzip2recover, verifying every block and then -copying the right blocks in the right order in another file. +one compressed data block (usually larger than 900 kB uncompressed), and +if no block is damaged in both files, then the data can be manually +recovered by splitting the files with bzip2recover, verifying every +block and then copying the right blocks in the right order in another +file. But if you used lzip, the data can be automatically recovered as long as no byte is damaged in both files. @@ -463,19 +464,26 @@ A four byte string, identifying the lzip format, with the value "LZIP" Just in case something needs to be modified in the future. 1 for now. @item DS (coded dictionary size, 1 byte) -Lzip divides the distance between any two powers of 2 into 8 equally -spaced intervals, named "wedges". The dictionary size is calculated by -taking a power of 2 (the base size) and substracting from it a number of -wedges between 0 and 7. The size of a wedge is (base_size / 16).@* +The dictionary size is calculated by taking a power of 2 (the base size) +and substracting from it a fraction between 0/16 and 7/16 of the base +size.@* 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.@* +Bits 7-5 contain the numerator of the fraction (0 to 7) to substract +from the base size to obtain the dictionary size.@* Example: 0xD3 = 2^19 - 6 * 2^15 = 512 KiB - 6 * 32 KiB = 320 KiB@* Valid values for dictionary size range from 4 KiB to 512 MiB. @item Lzma stream -The lzma stream, finished by an end of stream marker. Uses default values -for encoder properties. See the lzip manual for a full description. +The lzma stream, finished by an end of stream marker. Uses default +values for encoder properties. +@ifnothtml +@xref{Stream format,,,lzip}, +@end ifnothtml +@ifhtml +See +@uref{http://www.nongnu.org/lzip/manual/lzip_manual.html#Stream-format,,Stream format} +@end ifhtml +for a complete description. @item CRC32 (4 bytes) CRC of the uncompressed original data. @@ -538,6 +546,8 @@ lines are abridged diagnostic messages from lziprecover). @example lziprecover -v -R file.lz Copy of input file repaired successfully. +lziprecover -tv file_fixed.lz + ok mv file_fixed.lz file.lz @end example @@ -577,6 +587,9 @@ mount -t iso9660 -o loop,ro cdimage2 /mnt/cdimage cp /mnt/cdimage/backup.tar.lz rescued2.tar.lz umount /mnt/cdimage lziprecover -m -v -o backup.tar.lz rescued1.tar.lz rescued2.tar.lz + Input files merged successfully. +lziprecover -tv backup.tar.lz + ok @end example @sp 1 @@ -590,7 +603,9 @@ member 12 damaged in both copies. The correct file produced is saved in @example lziprecover -m -v -o big_db_00001.lz big_db1_00001.lz big_db2_00001.lz - Input files merged successfully + Input files merged successfully. +lziprecover -tv big_db_00001.lz + ok @end example |