Hi there,
I was trying to add a line of text in the middle line of a file.
I have counted the lines in the file, and then I divide it into 2, after that I am stuck on how am I suppose to append the line on that file? When I tried to use this command 'second line >> filename' it appends it at... (3 Replies)
Hi all,
I have set up a simple awk script to calculate the average of values that are printed out a number of times per second (the number of time the printing occurs varies). The data is of the format shown below:
1 4.43
1 3.65
1 2.45
2 7.65
2 8.23
2 5.65
3 4.65
3 6.21
.. ..
120... (4 Replies)
Hi
New to shell script and awk and need assistance on this problem. I need to use a variable to substitute a string in an external file and write the changed info to another file.
At first I did not know if you could use a variable as the sub value but the following showed me that I can.
... (3 Replies)
Hi, I have a very simple script like below:
for n in 10 20 30
do
for a in 30 40 50 60 70 80
do
for r in 2 3 4 5 6 7
do
m=$((r*a))
count=1
while
do
echo "a = " $a ", m = " $m ", n = " $n
... (2 Replies)
Hello;
Trying to figure out how to keep just the contents between the two search lines:
awk '/regexp_1/ ,/regexp_2/'
I do not want lines containing regexp_1 and regexp_2 in the output.
Thank you for any ideas
Video tutorial on how to use code tags in The UNIX and Linux Forums. (5 Replies)
Hello;
I need to print two previous lines after searching for a reg exp:
awk '/haywood/'
should produce the following
===================
p9J46THe020804 89922 Tue Oct 18 21:06 MAILER-DAEMON
(host map: lookup (haywood.com): deferred)
... (1 Reply)
Hi there, Im sure there is a simple explanation for this but I have a file like this with no balnk lines
peter
paul
john
I run the command
# var=`grep paul file.txt`
# echo $var
paul
# echo $var | wc -l
1
but when I grep for a value that isnt in the file, i still... (4 Replies)
Hello;
we have :
awk '/reg_exp/,0/
prints every line after the first occurrence of "reg_exp"
But if I want to print rest of the lines AFTER the last occurrence of "reg_exp",
how would I do it ??
Tried :
awk ' ! (/reg_exp/,0)'
But it errored...
Thank you for any... (5 Replies)
Discussion started by: delphys
5 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)