I have come across a weird behaviour in bash and would love to get to the bottom of it. If I execute
at the command line, I get:
However, if I wrap it in an assignment such as:
then I get
It doesn't show very well, but it has no trailing new line. It is as if the assignment is loosing the trailing new line (everything after the 'c'). Does anyone know how to turn this off?
I have a script wherein I access each line of the file using a FOR loop and then perform some operations in each line. The problem is each line that gets extracted in FOR loop truncates trailing blank spaces and control characters (^M) that is present at the end of each line. I don't wan this to... (5 Replies)
Hi guys,
I'm basically looking for some help with a bash script I've written. It's purpose is to assign process to individual CPU cores once that process hits 15% CPU usage or more. If it drops below 15%, it's unassigned again (using taskset).
My problem is that I can't think of a way to... (2 Replies)
Please take a look I am stuck on step 4
1. The problem statement, all variables and given/known data:
#!/bin/bash
### ULI101 - ASSIGNMENT #2 (PART A) - DUE DATE Wed, Aug 3, 2011, before 12 midnight.
###====================================================================================
###... (13 Replies)
Here's the assignment. I'll bold the parts that are rough for me. Unfortunately, that's quite a bit lol. The syntax is, of course, where my issues lie, for the most part. I don't have a lot of programming experience at all :/. I'd post what I've already done, but I'm so lost I really don't know... (1 Reply)
Suppose I have a file named Stuff in the same directory as my script. Does the following assign the file Stuff to a variable?
Var="Stuff"
Why doesn't this just assign the string Stuff? Or rather how would I assign the string Stuff to a variable in this situation?
Also, what exactly is... (3 Replies)
I have been trying to remove empty lines and lines just filled with spaces. I have used the following command which does work.
sed -i "/^\s*$/d"
Except it leaves one single trailing line at the very end of the file. For the life of me I cant figure out why I cant remove that last trailing... (2 Replies)
I have a little code block (executing on AIX 7.1) that I cannot understand why the NOTFREE=0 does not appear to be assigned even though it goes through that block. This causes a unary operator issue.
#!/bin/bash
PLATFORM="AIX"
NEEDSPC=3000
set -x
if ; then
lsvg | grep -v rootvg | while... (6 Replies)
Discussion started by: port43
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)