I'm trying to understand if it's possible to create a set of variables that are numbered based on another variable (using eval) in a loop, and then call on it before the loop ends.
As an example I've written a script called question (The fist command is to show what is the contents of the... (2 Replies)
Hi ,
I am new to shell scripting. i have a requirement say i will receive a file in a directory say /xyz.if that file stays in that directory more than 30 min i need to get a mail to my outlook.this should run for every 20 min in crontab.
can anyone help me? (8 Replies)
ok, so I have a shell script that can be called using the first argument ($1) or not. This argument is a word (Tim for example) and not an actual flag (-x for example). If I call the script with an argument and call the same script without one, it believes that I provided an argument. Note here... (2 Replies)
Hello All,
Maybe I'm Missing something here but I have NOOO idea what the heck is going on with this....?
I have a Variable that contains a PATTERN of what I'm considering "Illegal Characters". So what I'm doing is looping
through a string containing some of these "Illegal Characters". Now... (5 Replies)
Hi,
I want to read file multiple times. Right now i am using while loop but that is not working.
ex.
While read line
do
while read line2
do
echo stmt1
#processing some data based on data.,
done < file2.txt
done < file1.txt # This will have 10... (4 Replies)
hi all,
i want to make a bash script so it can monitor directory sizes ie if it stays the same size (for a certain time) i want it to run the script but if there still copying and the directory increases in size do not run the script
i have heard "inotifywait" can do this, but theres... (7 Replies)
Discussion started by: robertkwild
7 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)