9 More Discussions You Might Find Interesting
1. UNIX for Dummies Questions & Answers
Hi everyone,
Is it possible to define blank vaianbles and prompt user to fill them during the script execution?
A very simple example:
INPUT=
OUTPUT=
cut -f1-4 $INPUT | sed 's/hello/goodbye/g' | sort -uV > $OUTPUTThank you in advance!
Best wishes (2 Replies)
Discussion started by: lsantome
2 Replies
2. Shell Programming and Scripting
Hello,
I would like to modify an existing script of mine that uses a manually defined "MCVERSION" variable and make it define that variable instead based on this JSON file stored online:
https://s3.amazonaws.com/Minecraft.Download/versions/versions.json
Within that JSON, I 'm looking for... (4 Replies)
Discussion started by: nbsparks
4 Replies
3. Shell Programming and Scripting
HI
I have file A.txt
_1A
_2A
_3A
_4A
I want define all as different variable.
$1A=_1A
$2B=_2A
$3C=_3A
$4D=_4A
Now i can use any variable in my script. (3 Replies)
Discussion started by: pareshkp
3 Replies
4. Shell Programming and Scripting
Hi,
Is it possible in perl to have a hash defined with variables as theirs key values, like:
%account = ('username' => 'boy', 'password' => $password);
Thanks (1 Reply)
Discussion started by: zing_foru
1 Replies
5. Shell Programming and Scripting
Hi, Unix Gurus,
In our existing file, there is a script like
#!/bin/sh
step=${1:-0}
cur_step=10
if
...
My question is what's "${1:-0}" mean? I know it defines a variable but I don't know what's (1:-0) mean?
:wall:
Thanks in advance. (2 Replies)
Discussion started by: ken002
2 Replies
6. Shell Programming and Scripting
Hi all,
I have a variable say var1 (output from somewhere, which I can't change)which store something like this:
echo $var1
name=fred
age=25
address="123 abc"
password=pass1234
how can I make the variable $name, $age, $address and $password contain the info?
I mean do this in a... (1 Reply)
Discussion started by: freddy1228
1 Replies
7. UNIX for Dummies Questions & Answers
I have a variable with a value of "05". When I add one to that variable, using the command: CURR_YY=`expr $CURR_YY + 1`, I get the value of "6", losing the leading zero (which is needed for passing to another script). How do I keep the leading zero?
Thank you! (10 Replies)
Discussion started by: cbarker
10 Replies
8. Shell Programming and Scripting
Hello,
I just want to know how If it's possiple to define 2 variable using foreach command ???
I have directory inside that directory around 1000 file, I want to rename all of this files to something I have it in a list. Example :-
------This is what in my directory----------
d1
d2... (14 Replies)
Discussion started by: geoquest
14 Replies
9. UNIX for Dummies Questions & Answers
I am using korn shell unix.
I have a script that I am working with to do a check for me using a text file.
#finds "Time" from the text file and cuts the second field from the #line
A= grep Time test.txt | cut -f2
# the "#Missing" is being pulled from the second field of the text... (1 Reply)
Discussion started by: cspcspcsp
1 Replies
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)