I am spooling a file from oracle and trying to delete the last line of the spooled file which I am unable to do.
Problem is that this file can have multiple records each time and I have no way of knowing how many because the amount can vary. I had an idea of using a while loop to read the... (1 Reply)
I am trying deleting lines from a text file using sed..
sed '/OBJECT="ABC/{N;N;N;d; }'
will do if i have to delete lines starting with Object and next 3 lines
but I was looking for a way to delet lines starting with OBJECT and all the lines till it reaches a blank lines ..or it reaches a... (8 Replies)
Hi
I have a file & always I need to remove or delete last 2 lines from that file. So in a file if I have 10 lines then it should return me first 8 lines.
Can someone help me? (4 Replies)
I have a file with 65 sets of 35 coordinates, and would like to isolate these coordinates so that I can easily copy the coordinates to another file. The problem is, I've got a 9 line header before each set of coordinates (so each set is 44 lines long). There are a zillion threads out there about... (3 Replies)
Hi All,
I am trying to extract lines bsed on pattern matching../mp straight-flow/
Extracted output should be saved in meta_string , but the code is not working in that manner,saving repeated lines. can anyone please suggest where am i going wrong.
/mp straight-flow/ {... (6 Replies)
I have a log file that I am processing. This contains messages from and to a server (requests and responses).
The responses to requests may not be in order i.e. we can have a response to a request after several requests are sent, and in some error cases there may not be any response message.
... (2 Replies)
hi all,
i have got a scenario in which i need to delete all the lines that ends with file names.
e.g.
input can be
cms/images/services_icons/callback.png
cms/cms/images/services_icons/sync.php
cms/cms/images/services_icons
and output should be
cms/cms/images/services_icons
... (13 Replies)
Hello, im using ex to manipulate some text. Im trying to delete all the lines except those on which a certain regex can be found.
the important part of the script:
ex temp << 'HERE'
g/regex/p
HERE
this command prints the lines I want to end up with, but it doesnt delete the others.... (2 Replies)
Hi All,
I want to write a script which first check the line counts of a file if its more than 500 it deletes rest except the last 500..
I tried sed but it looks sed counts line numbers from the head & not from tail.. May be I need a wc -l frist then apply if statement & pass on the line count... (17 Replies)
Say you want to clear your .bash_history except for the first 25 lines. Try:
sed -i -e 26,500d .bash_historyI have a some frequently-used routines parked in the first few lines, and they kept getting overwritten by more recent commands. (2 Replies)
Discussion started by: Xubuntu56
2 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)