i've reworked some code from an earlier post, and it isn't working as expected
i've simplified it to try and find the problem. i spent hours trying to figure out what is wrong, eventually thinking there was a bug in perl or a problem with my computer. but, i've tried it on 3 machines with the... (5 Replies)
Hi All,
I have a file that I need to be able to find a pattern match on a line, search that line for a text pattern, and replace that text.
An example of 4 lines in my file is:
1. MatchText_randomNumberOfText moreData ReplaceMe moreData
2. MatchText_randomNumberOfText moreData moreData... (4 Replies)
Hi i am trying to write a perl program where i have to open a
1)directory "unit"
2) rename the files in the dir say file1.txt;file2.txt...file5.txt
to file1_a.txt;file2_a.txt,....file5_a.txt ;file1_x.txt ;file2_x.txt
3) open these renamed files and replace the words
lets say file1_a.txt... (7 Replies)
Hi,
I have thousands of files in a directory that have the following 2 formats:
289620178.aln
289620179.aln
289620180.aln
289620183.aln
289620184.aln
289620185.aln
289620186.aln
289620187.aln
289620188.aln
289620189.aln
289620190.aln
289620192.aln....
and:
alnCDS_1.fasta (1 Reply)
in one of my script..I have some thing like
john:christina : one::
and i want to make it like
john:chritina:two:(date command):jackey:
basically change 'one' to 'two' and run date :command and add other name: (30 Replies)
Hi, could anyone help me with this, tried several times but still not getting it right or having enough grounding to do it outside of javascript: Using awk or sed or bash: need to go through a text file using a for next loop, replacing substrings in the file that consist of a potentially multi... (3 Replies)
Learning, stumbling! My progress in shell scripting is slow. Now I have this doubt:
I have the following file (users.txt):
AU0909,on
AU0309,off
AU0209,on
AU0109,off
And this file (userson.txt)
AU0909
AU0209
AU0109
AU0309
I just want to set those users on userson.txt to "off" in... (14 Replies)
Hello,
I am using sed in a for loop to replace text in a 100MB file. I have about 55,000 entries to convert in a csv file with two entries per line. The following script works to search file.txt for the first field from conversion.csv and then replace it with the second field. While it works fine,... (15 Replies)
HEllo!!
I need a script in perl that see inside a file(file.txt) that has only one row.
The row contains only this text:
logs_yearly = 20120628113345
I want that the script does this:
"Search in the file, if the date 20120628 is actual date"
Thank you!!
---------- Post... (4 Replies)
Experts - Any advice on how to get a hash value in a foreach loop?
Values print correctly on standalone print statements, but I can't access value
in foreach loop.
See sample code below and thanks in advance.
foreach my $z (sort keys %hash) {
for $y (@{$hash{$z}}) {
print "$z... (6 Replies)
Discussion started by: timj123
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)