i have a lot of messages file in the var directory i want to delete
now i want to keep messages.1 to messages.10 and then delete everything else after 10 which is like 10 to 96
obviously i cant delete these files individual, can someone tell me the command to delete messages.11 to... (1 Reply)
What does 'directory=`pwd $1` ' mean, I know pwd is present working directory, so does that command take the present working directory of the directory the user is in depending on the varible ($1)? (2 Replies)
When I use the mv command like say, mv file1 ../, it will move file1 to the parent directory of my current working directory. But where would the file go if I do mv file ... (with 3 periods), where would this move file1? (4 Replies)
$ echo 2 * 3 > 5 is a valid inequality.
This will create a file in the current directory named '5' with the number '2' in it, the names of all the files in the current directory, followed by the number '3' and 'is a valid inequality.'
What I do not understand is why 'is a valid inequality' gets... (2 Replies)
I am going through the Unix Made Easy second edition book by John Muster. So far it's been very informative and I can tell it may be a bit out of date.
In one of the exercises it talks about the "sort" command and using it to sort column's of data etc. The "sort" command has changed a bit and... (1 Reply)
I am scratching my head right now. I am trying to archive a ton of files in a directory. I am attempting to tar them by year. On our development server if I type ls *_2008* it returns all of the files I am expecting to see. (The format of the filename includes xx_xx_xxx_2008-09-29_xxx.xxxx.xxxx)... (8 Replies)
Hi,
can you please tell me what is the purpose of the following line:
sh -c /home/dir/script.sh || exit 33
what i am confused is the || is this an OR boolean, or it might have some other purpose.
do you know how this works ?
i believe the first to run is the /home/dir/script.sh but what... (4 Replies)
Discussion started by: antoniotunin
4 Replies
LEARN ABOUT SUSE
bzz
BZZ(1) DjVuLibre-3.5 BZZ(1)NAME
bzz - DjVu general purpose compression utility.
SYNOPSIS
Encoding:
bzz -e[blocksize] inputfile outputfile
Decoding:
bzz -d inputfile outputfile
DESCRIPTION
The first form of the command line (option -e ) compresses the data from file inputfile and writes the compressed data into outputfile.
The second form of the command line (option -d ) decompressed file inputfile and writes the output to outputfile.
OPTIONS -d Decoding mode.
-e[blocksize]
Encoding mode. The optional argument blocksize specifies the size of the input file blocks processed by the Burrows-Wheeler trans-
form expressed in kilobytes. The default block sizes is 2048 KB. The maximal block size is 4096 KB. Specifying a larger block
size usually produces higher compression ratios and increases the memory requirements of both the encoder and decoder. It is use-
less to specify a block size that is larger than the input file.
ALGORITHMS
The Burrows-Wheeler transform is performed using a combination of the Karp-Miller-Rosenberg and the Bentley-Sedgewick algorithms. This is
comparable to (Sadakane, DCC 98) with a slightly more flexible ranking scheme. Symbols are then ordered according to a running estimate of
their occurrence frequencies. The symbol ranks are then coded using a simple fixed tree and the ZP binary adaptive coder (Bottou, DCC 98).
The Burrows-Wheeler transform is also used in the well known compressor bzip2. The originality of bzz is the use of the ZP adaptive coder.
The adaptation noise can cost up to 5 percent in file size, but this penalty is usually offset by the benefits of adaptation.
PERFORMANCE
The following table shows comparative results (in bits per character) on the Canterbury Corpus ( http://corpus.canterbury.ac.nz ). The very
good bzz performance on the spreadsheet file excl puts the weighted average ahead of much more sophisticated compressors such as fsmx.
+-------------------------------------------------------------------------------------------------------------+
| Compression performance |
| text fax csrc excl sprc tech poem html lisp man play Weighted Average |
+-------------------------------------------------------------------------------------------------------------+
| compress 3.27 0.97 3.56 2.41 4.21 3.06 3.38 3.68 3.90 4.43 3.51 2.55 3.31 |
| gzip -9 2.85 0.82 2.24 1.63 2.67 2.71 3.23 2.59 2.65 3.31 3.12 2.08 2.53 |
| bzip2 -9 2.27 0.78 2.18 1.01 2.70 2.02 2.42 2.48 2.79 3.33 2.53 1.54 2.23 |
| ppmd 2.31 0.99 2.11 1.08 2.68 2.19 2.48 2.38 2.43 3.00 2.53 1.65 2.20 |
| fsmx 2.10 0.79 1.89 1.48 2.52 1.84 2.21 2.24 2.29 2.91 2.35 1.63 2.06 |
| bzz 2.25 0.76 2.13 0.78 2.67 2.00 2.40 2.52 2.60 3.19 2.52 1.44 2.16 |
+-------------------------------------------------------------------------------------------------------------+
Note that DjVu contributors have several entries in this table. Program compress was written some time ago by Joe Orost. Program ppmd is
an improvement of the PPM-C method invented by Paul Howard.
CREDITS
Program bzz was written by Leon Bottou <leonb@users.sourceforge.net> and was then improved by Andrei Erofeev <andrew_erofeev@yahoo.com>,
Bill Riemers <docbill@sourceforge.net> and many others.
SEE ALSO djvu(1), compress(1), gzip(1), bzip2(1)DjVuLibre-3.5 10/11/2001 BZZ(1)