02-23-2010
8 More Discussions You Might Find Interesting
1. UNIX for Dummies Questions & Answers
Ok, another fun hiccup in my UNIX learning curve. I am trying to count the number of occurrences of an IP address across multiple files named example.hits. I can extract the number of occurrences from the files individually but when you use grep -c with multiple files you get the output similar to... (5 Replies)
Discussion started by: MrAd
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2. Shell Programming and Scripting
Hello all,
Below is what I am trying to accomplish:
I have a file that looks like this
/* ----------------- xxxx.y_abcd_00000050 ----------------- */
jdghjghkla
sadgsdags
asdgsdgasd
asdgsagasdg
/* ----------------- xxxx.y_abcd_00000055 ----------------- */
sdgsdg
sdgxcvzxcbv... (8 Replies)
Discussion started by: alfredo123
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3. Shell Programming and Scripting
Good afternoon! Im new at scripting and Im trying to write a script to
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4. Shell Programming and Scripting
I have a file like the one below. Each record is separated with >
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5. UNIX for Dummies Questions & Answers
I'm Unix. I'm looking at "df" on Unix now and below is an example. It's lists the filesystems out in 512-blocks, I need this in 4k blocks. Is there a way to do this in Unix or do I manually convert and how?
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6. Shell Programming and Scripting
Hello,
I have a file like this:
FILE.TXT:
(define argc :: int)
(assert ( > argc 1))
(assert ( = argc 1))
<check>
#
(define c :: float)
(assert ( > c 0))
(assert ( = c 0))
<check>
#
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Discussion started by: paramad
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7. Shell Programming and Scripting
Hello,
Searched for a while and found some "line-to-column" script. My case is similar but with multiple fields each row:
S02 Length Per
S02 7043 3.864
S02 54477 29.89
S02 104841 57.52
S03 Length Per
S03 1150 0.835
S03 1321 0.96
S03 ... (9 Replies)
Discussion started by: yifangt
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8. Shell Programming and Scripting
please help, I have a huge file with blocks of data which I need to convert to a tabular format.
Input
sample
id: GO:0000017
name: alpha-glucoside transport
namespace: biological_process
def: "The directed movement of alpha-glucosides into, out of or within a cell, or between... (3 Replies)
Discussion started by: ritakadm
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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)