I am trying to using pipe (|) with ! (not) operator to list all the other files except the latest two and I am using the following command.
$ ls -ltr *.lst|!(tail -2)
ksh: 20050211180252.lst: cannot execute
but it is trying to execute the file returned by tail -2. I am able to do that in 4... (8 Replies)
Hi ,
I have found a interesting thing about tail command:
when I tried to use 'tail -1 *' to look at every file with the current derectory, I only got one line of result of one file.
But if I use 'head -1 *', I would get multiple lines.
Is there a way to do get multiple lines with 'tail -1 *'... (3 Replies)
I was wondering how can I do this
I have file myfile.txt
wc -l is: 5 000 000
I have to remove first 1 000 000 lines from header..
I tryed with tail -4000000 myfile.txt>newfile.txt
but it does not work...
any help?? (2 Replies)
HI i have to copy the last 5000 lines form a log file and copy the same in the same file .overwriting the same log file.
ex: tail -5000 testfile1 > testfile2
cat testfile2
mv tesftfile2 testfile1
will produce the correct result.but i want to have this done in one line???? (4 Replies)
Hi All,
My query seems to be silly but Iam unable to find where the exact problem lies.
I have a script to unzip set of files
here is the script
#!/bin/ksh
Count=`cat /home/gaddamja/Tempfile | wc -l`
while
do
Filename=`cat /home/gaddamja/Tempfile |tail -$Count | head -1`
cd... (7 Replies)
Please help with the following command
tail -f /appdata/logs/alert_audit517.txt | grep "Sep 02"
The problem I have is with the file name "alert_audit517.txt". The 3 digit number at the end of the file name changes, so I need the file name to use a wildcard. Ive tried alert_audit***.txt, but... (5 Replies)
Hi does anyone know how to create a file using the tail command? My book has this file I need to create and it says to use the tail command and that it is possible but I have no idea. Thanks. (4 Replies)
Hello,
I wrote a script and part of the script, I have a validation to check if the file has <EOF> on the last line of the
file. If it does not have a <EOF>, then a message has to be written to a log file.
the code snippet shown below works fine, but it writes the below message if the... (1 Reply)
Use and complete the template provided. The entire template must be completed. If you don't, your post may be deleted!
1. The problem statement, all variables and given/known data:
Devise a chain of filters using some or all of the following programs pr, cut, cat, tail to
display a numbered... (8 Replies)
Hi Team,
Can anyone help me here:
I have to access server logs via putty and these logs file is a trailing file (continously updating) with ERROR and WARNINGS... I need to know if I can pull this trailing file to a local drive so that I can do some higlighting on some keywords through Notepad... (13 Replies)
Discussion started by: jitensetia
13 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)