How do I extract 5th to 10th characters of string as given below stored in a shell variable.
"ab cd ef gh ij kl"
How is cut to be used on this?
Thanks for any help. (1 Reply)
Is there a way that i can get something like this to work:
Number=`expr 80 \* 10.69`
i.e. To multiply an integer by a decimal or a decimal by a decimal etc...?
thanks (10 Replies)
Hi,
Need to extract a string from one file and search the same in other files.
Ex:
I have file1 of hundred lines with no delimiters not even space.
I have 3 more files.
I should get 1 to 10 characters say substring from each line of file1 and search that string in rest of the files and get... (1 Reply)
Hello. I have a problem with AWK and floats below 0 in a script.
It may be simplified to this line (please, take into account that my "locale" is Spanish, so the system will read "," as decimal separator):
echo -1,25 2,55745 0,33 ,278 | awk '{print $1+1, $2+1, $3+1, $4+1}'... getting:
-0,25... (4 Replies)
I am trying to extract a hyperlink from a html document using awk. I have managed to output in the format... href="index.html"> where i would like it just to output index.html. Any ideas on how i would do this?
Thanks (2 Replies)
I am using gawk in a dos shell in windows xp and want to read a datafile and reformat it.
The datafile consists of columns of integers, floating point numbers and text strings. Each column is a fixed width and each column contains the same data type, eg all integers, all text.
I am looking for a... (0 Replies)
I want to make computations using floats. This cannot be done with csh. ksh seem to have a problem as well. What is good shell for computations without having to resort to bc or awk? How about python? (5 Replies)
Hi,
I am trying to remove lines once a string is found till another string is found including the start string and end string. I want to basically grab all the lines starting with color (closing bracket). PS: The line after the closing bracket for color could be anything (currently 'more').... (1 Reply)
Hello,
I have two files.
File 1 is a list of interested IDs
Ex1
Ex2
Ex3File 2 is the original file with over 8000 columns and 20 millions rows and is a compressed file .gz
Ex1 xx xx xx xx ....
Ex2 xx xx xx xx ....
Ex2 xx xx xx xx ....Now I need to extract the information for all the IDs of... (4 Replies)
Hello.
First best wishes for everybody.
here is the input file ("$INPUT1") contents :
BASH_FUNC_message_begin_script%%=() { local -a L_ARRAY;
BASH_FUNC_message_debug%%=() { local -a L_ARRAY;
BASH_FUNC_message_end_script%%=() { local -a L_ARRAY;
BASH_FUNC_message_error%%=() { local... (3 Replies)
Discussion started by: jcdole
3 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)