Need help here , I Have a file which has as a number of rows (records) in it .
I Have another file which has few more records :
All I want is a code which could remove the last line i.e. tail of the first file and then insert the records from the second file and then again insert the tail which was removed earlier .
hi! I am a newbee. I would really appreciate if you can answer the following question:
I have a huge data file, 214MB with several coloumns. I need to delete the very last line of the file. Everything I know takes a lot of time to do it ( because I have to open the file in an editor or run a... (3 Replies)
I have a flat file and need to count no of records in the file less the header and the trailer record.
I would appreciate any and all asistance
Thanks
Hadi Lalani (2 Replies)
Hi all,
I'm new in unix scripting and I've a problem with a script... :confused:
I need to read a file, add some fields in the records, and write them in another file, but even when I simply read and write the records, the shell interprets some caracters and the result is that the records... (5 Replies)
Hi everyone.
I am a newbie to Linux stuff. I have this kind of problem which couldn't solve alone. I have a text file with records separated by empty lines like this:
ID: 20
Name: X
Age: 19
ID: 21
Name: Z
ID: 22
Email: xxx@yahoo.com
Name: Y
Age: 19
I want to grep records that... (4 Replies)
Hi,
I am having a file which is fix length and comma seperated. And I want to replace values for one column.
I am reading file line by line in variable $LINE and then replacing the string.
Problem is after changing value and writing new file temp5.txt, formating of original file is getting... (8 Replies)
I have a text file that has data like:
Data "12345#22"
Fred
ID 12345
Age 45
Wilma
Dino
Data "123#22"
Tarzan
ID 123
Age 33
Jane
I need to figure out a way of adding 1,000,000 to the specific lines (always same format) in the file, so it becomes:
Data "1012345#22"
Fred
ID... (16 Replies)
I have 2 files
"File 1" is delimited by ";" and "File 2" is delimited by "|".
File 1 below (3 record shown):
Doc1;03/01/2012;New York;6 Main Street;Mr. Smith 1;Mr. Jones
Doc2;03/01/2012;Syracuse;876 Broadway;John Davis;Barbara Lull
Doc3;03/01/2012;Buffalo;779 Old Windy Road;Charles... (2 Replies)
Hi I am new to shell programming in unix
Please if I can provide help.
I have a file structure of a header record and "N" detail records.
The header record will be the total number of detail records
I need to split the file in 2:
One for the header
Another for all detail records
Could... (1 Reply)
Dear Guru's
I'm using Putty and want to edit a file. I know we generally use vi editor to do it. As I'm not good in using vi editor, I want to convert the vi into something like text pad. Is there any option in Putty to do the same ? Thanks for your response.
Srini (6 Replies)
Discussion started by: thummi9090
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)