Once again, I know basic scripting if you can call it that
Whats really throwing me off here is the variables in {}
What is that piece of code trying to do exactly? Well, from the info I've given.
This is a different piece I've noticed that leads back to the {}. I'll see a file name, say:
BKFILE=$FTPDIR/$TDG/${ZFILE}.out
And I'll know the value of $FTPDIR and $TDG, but where is it getting the value for ${ZFILE} when it hasnt been defined previously in the script.
I have a question about C program for Unix:
Do we have to intialize every variable before we use them in C?
I thought we have to untill I found some programs are not intialize the variable before they were used. (2 Replies)
hi there,
In my shell script I'm using a variable $ICO to speicfy the type of file that I'm processing e.g. VFR = France.
further in my shell I'm trying to programatically set the sql file thtat I want to run :-
REPORTTXT=/tmp/$ICO3hr.dat
however when I check the value (as below) :-
... (4 Replies)
Hi, this is probably very easy but, how do I define a variable for more than one line.
For example:
var1='more
than
one
line'
when I call it, I want it to be exactly like this, don't want all the words on the same line. (10 Replies)
I have been working on a script that executes on a number of different operating systems. As a result I was trying to set a variable or perhaps variable array depending on the OS. I tried the following using eval and such but so far have not had any luck. Is there a way to do something like the... (4 Replies)
Hi i have two question
1. Yahoo!
In above there are total three words
1.1. www
1.2. yahoo
1.3 com
how can i take all three things in different variable, i dont understand that how to separate dot.
it looks like that
a=www
b=yahoo
c=com
2. i have variable xyz whois value... (7 Replies)
I have a variable:
$FILENAME = /XXXX/XXXX/XXXX/file.dat
I want to set another variable that will give me this:
$FILENAME2=filea.dat
So basically i'm chopping up variable $FILENAME.
Not sure cut will do this as i'm looking at different directories so the characther length may be... (2 Replies)
Hello,
First post for Newbie as I am stumped. I need to get certain elements for a specific PID from the ps command. I am attempting to pass the value for the PID I want to retrieve the information for as a variable. When the following is run without using a variable, setting a specific PID,... (3 Replies)
Hi,
I'm trying to replace a string with the contents of a file.. I found the below thread that shows how to do this but is there any way to use a variable as the file name in the nawk command?.. When I try I get an error saying
while read groupsvar
do
... (5 Replies)
Hi...I am trying to make a script like this:
mmc=123
echo "$mmc" > 123.txt
The variable "mmc" has to be declared right on the beginning of the script, so when I open 123.txt, I get:
123
My question is, how can I "echo" '$mmc' into 123.txt, retaining the '$mmc' phrase? Which means when... (10 Replies)
Discussion started by: Ryuinferno
10 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)
02-28-2008
