Hi,
If, in a text file a string is expected at a certain fixed position(for eg at position 5 or from 5-10 on every line)
how to check whether data is present on that position or not?
Thnx in advance (6 Replies)
Hello All,
I have written shell script whcih at the max 3 parameters.
When only one commandline argument and other two command line arguments are passed as empty string like
eg : archive ' ' ' '
Then i need to check whether the commandline... (12 Replies)
hi
I m executing a shell script in which records are to be fetched from a table. If the sql that is running empty result set it is displaying "table null is empty !". I dont want this msg on the standard output. COuld you please help me in this regard (3 Replies)
I have an input file having 7 fields delimited by ,
eg :
1,ABC,hg,1,2,34,3
2,hj,YU,2,3,4,
3,JU,kl,4,5,7,
4,JK,KJ,3,56,4,5
The seventh field here in some lines is empty, whereas the other lines there is a value.
How do I insert string NULL at this location (7th loc) for these lines where... (8 Replies)
I am reading from a file and executing the jobs with/without parameters as the job requires.
File
job1 R
job2
job3 Y 123
if
then
<job>.ksh
else
<job>.ksh $params
fi
This works fine if the line read from the file has parameters
it executes like job1.ksh R
But for... (2 Replies)
Hello
So i have that script collection, in which i have a single script to create a configuration file.
In there, i have multiple occourences of something like this:
prj_title=$(tui-read "What is the TITLE? ($prj_name):")
] && prj_title="${prj_name/_/ }"
They all work as expected, if... (5 Replies)
Hi Team,
I have a file abc.dat which is a empty file. But it has null record in first line. I need to identify this unique file and handle it separately.
scenario 1:
abc/dw> wc abc.dat
1 0 1 abc.dat
abc/dw> cat abc.dat
abc/dw>
scenario 2:
abc/dw> wc pqr.dat
0 0 0 pqr.dat... (3 Replies)
I am working an some if then statements for a script.
I want to be able to check for alpha characters or empty out put then exit out.
if ]];
echo "Serial Number Invaild"
then exit 3;
How do I account if the output is empty or null in this in this statement.
Many thanks (6 Replies)
Discussion started by: andysensible
6 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)