Hi All,
I have two comma separated value(CSV) files, say FileA and FileB.
The contents looks like that shown below.
FileA
EmpNo,Name,Age,Sex,
1000,ABC,23,M,
1001,DES,24,F, ... (2 Replies)
AIX 5.3 / KSH
I have a Java application which creates a log file a.log. I have a KSH script which does the following action
cp a.log /directory2/b.log
> a.log
After this the file size goes to 0 as per "ls -l"
Then next time when the application writes into this file, the file size... (4 Replies)
I want to gzip a file and append the creation date to the end of the file. How can I accomplish this task. Basically they are log files which need a creation date stamp appended to make sure they do not overwrite other log files.
-jack (3 Replies)
I have a file "sample.txt" with the content as below:
Hi
This is a Sample Text.
I need a single command using cat which serve the following purpose.
1.display the contents of sample.txt
2.append some text to it
3. and then exit
But, all should be served by a sinle command.:confused: (1 Reply)
Hi Experts,
I am working on HP-UX. I am new to shell scripting. I would like to have a shell script which will prefix:
1. "H|" before first row of my file and,
2. "T" for all other rows of the file.
For Example - File before running the script 20100430|4123451810|218.50|TC
20100430 ... (4 Replies)
Hi ,
I have a file myhost.txt which contains below,
127.0.0.1 localhost
1.17.1.5 atrpx958
11.17.10.11 atrpx958zone nsybhost
I need to append words only after "atrpx958" like 'myhost' and 'libhost' and not after atrpx958zone.
How to search the word atrpx958(which is hostname) only,... (5 Replies)
Hi ladies and gentleman.. I have two text file with me. I need to replace one of the file content to another file if one both files have a matching pattern.
Example:
text1.txt:
ABCD 1234567,HELLO_WORLDA,HELLO_WORLDB
DCBA 3456789,HELLO_WORLDE,HELLO_WORLDF
text2.txt:
XXXX,ABCD... (25 Replies)
Hi,
I need help with this-
input.txt :
L B white
X Y white
A B brown
M Y black
Read this input file and if 3rd column is "white", then add specific lines to another file insert.txt.
If 3rd column is brown, add different set of lines to insert.txt, and so on.
For example, the given... (6 Replies)
In the awk below I am trying to cp and paste each matching line in f2 to $3 in f1 if $2 of f1 is in the line in f2 somewhere. There will always be a match (usually more then 1) and my actual data is much larger (several hundreds of lines) in both f1 and f2. When the line in f2 is pasted to $3 in... (4 Replies)
Discussion started by: cmccabe
4 Replies
LEARN ABOUT DEBIAN
bup-margin
bup-margin(1) General Commands Manual bup-margin(1)NAME
bup-margin - figure out your deduplication safety margin
SYNOPSIS
bup margin [options...]
DESCRIPTION
bup margin iterates through all objects in your bup repository, calculating the largest number of prefix bits shared between any two
entries. This number, n, identifies the longest subset of SHA-1 you could use and still encounter a collision between your object ids.
For example, one system that was tested had a collection of 11 million objects (70 GB), and bup margin returned 45. That means a 46-bit
hash would be sufficient to avoid all collisions among that set of objects; each object in that repository could be uniquely identified by
its first 46 bits.
The number of bits needed seems to increase by about 1 or 2 for every doubling of the number of objects. Since SHA-1 hashes have 160 bits,
that leaves 115 bits of margin. Of course, because SHA-1 hashes are essentially random, it's theoretically possible to use many more bits
with far fewer objects.
If you're paranoid about the possibility of SHA-1 collisions, you can monitor your repository by running bup margin occasionally to see if
you're getting dangerously close to 160 bits.
OPTIONS --predict
Guess the offset into each index file where a particular object will appear, and report the maximum deviation of the correct answer
from the guess. This is potentially useful for tuning an interpolation search algorithm.
--ignore-midx
don't use .midx files, use only .idx files. This is only really useful when used with --predict.
EXAMPLE
$ bup margin
Reading indexes: 100.00% (1612581/1612581), done.
40
40 matching prefix bits
1.94 bits per doubling
120 bits (61.86 doublings) remaining
4.19338e+18 times larger is possible
Everyone on earth could have 625878182 data sets
like yours, all in one repository, and we would
expect 1 object collision.
$ bup margin --predict
PackIdxList: using 1 index.
Reading indexes: 100.00% (1612581/1612581), done.
915 of 1612581 (0.057%)
SEE ALSO bup-midx(1), bup-save(1)BUP
Part of the bup(1) suite.
AUTHORS
Avery Pennarun <apenwarr@gmail.com>.
Bup unknown-bup-margin(1)