Hi,
I was trying to use this particular option of grep
grep -r 'Search_pattern' *
This command should ideally search all the occurrences of Search_pattern recursively within a directory & print it on shell prompt. But this command is not doing what is expected. It just displays nothin!
... (8 Replies)
I am trying to cat a file and then grep that file for a number. I can do it fine on other files but this particular file will not do anything. I tried running it on an older file from the same device but it is just not working. The file is nothing more than a flat file on a unix box. Here is just a... (3 Replies)
This condition is not able to grep , can any one tell what's wrong with this part.
I am able to see from unix command but not with host script.
echo "Checking for Loader Status " >> $REPFILE
if test $? = 0
then
echo "Successful termination of SQL*Loader "$LOADER1 >>... (5 Replies)
Hi,
I've prob in doing grep. I want to grep line staring with number 531250 in the 1st column from a file (example in picture attached below)
using command
grep -w "531250" file
my ideal result should be
531250 1 21 42.1 100 1e-05 ... (8 Replies)
Hello, I'm going crazy about this. I'm using grep to filter some values as in pas -ef | grep asterisk. When I use the same with -f somefile something weird happens, if somefile is created with vi it'll work, if somefile is created with vi but values are pasted from an Excell file it will not work.... (2 Replies)
Hi all,
Am writing a ksh script where I am looking for processes that has gone defunct and all of which has the same PPID
PID is the variable that I need to match as this is the process ID of the processes that has gone defunct
Am just curious how come the following DOES NOT work?
ps... (6 Replies)
Hi, I am currently working on a Bash shell script that
- Downloads a webpage, in this case youtube.com
- Extracts Number of views, Extracts Title of video, Extracts User who made it, and lastly Duration. Then I have to Out put this into columns.
To me this sounds like crazyness. I'm very new... (6 Replies)
Hi,
If I hard code a value in the grep it works fine from script, when I use variable it doesn't work. On a seperate note, some lines (during testing) works fine from command line but not from scirpt.
#!/bin/bash
# Will fetch the (oldest - as ls will sort by name by default)Date in the... (7 Replies)
Hi all,
I got a new mac and can't get grep, awk etc to work.
I tried the following command:
grep DICER test.txt
output:
AGOER
text.txt looks like this:
DICER
DICER
AGOWhat is wrong?
Please use code tags (23 Replies)
I have made a program that reads a text file and checks for palindromic words and then outputs them. They each appear on a new line with a count of the number of occurences beside each of the words.
Requirements for being classed as palindrome are that the word must have at least 3 letters and... (7 Replies)
Discussion started by: greenhouse91
7 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)