The pattern1, pattern2 form of an expression is called a range pattern. It matches all input records starting with a record that matches pattern1, and continuing until a record that matches pattern2, inclusive.
may be a better choice. If you have:
you will get:
which is the lines you want to remove. You cannot negate the pattern:
instead, you have to do something like:
which will print the lines not inside the pattern.
Hope this helps.
Hi,
I want to use the mailx command or sendmail command in perl script.
I am trying this one and getting error:
system "mailx -s \"Test mail\" $ar1";
Error:
The flags you gave are used only when sending mail. (10 Replies)
Hi,
To run a perl script i am giving command like this in DOS prompt
d:> perl D:\<dir_name>\<dir_name>\sample.pl
Its throwing the following error while running the above
syntax error at <eval 4> line 1, near "use D:"
Can anyone help? (3 Replies)
Hi
How to call a shell scripting through a Perl scripting? Actually I need some value from Shell scripting and passes in the Perl scripting. So how can i do this? (2 Replies)
Hi All,
Need help configuring Active Perl on Windows Vista.
I am trying to install Active Perl on Windows Vista.
The version of Active Perl i am trying to install is : ActivePerl 5.10.1 Build 1006
After installing it through cmd, When i try to run perl -v to check the version, i get the... (2 Replies)
Hi all,
I would like to start developping some good scripting skills. Do you think it would be best to start with shell scripting or Perl? I already got a fundation, really basics, in perl. but I am wondering what would be best to be good at first.
Can you please help me determine which one to... (14 Replies)
Gents,
I have been working in a Solaris/Unix environment for about 9 months. I took some linux classses online before getting the job. But, I am not very good at scripting. I want to learn how to script. Do you think that I should start with Shell scripting or Perl? I wanted to continue with... (2 Replies)
I have create this shell script
#!/bin/sh
if ; then
echo "Usage: ./script <filename>"
exit 1
elif ; then
fname="$1"
fi
output="output.txt"
i=0 ... (11 Replies)
Discussion started by: Evelin90
11 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)