I have a CSV file with a variable number of fields per record. How do I print lines of a certain number of fields only? Several permutations of the following (including the use of escape characters) have failed to retrieve the line I'm after (1,2,3,4)...
$ cat myfile
1,2,3,4
1,2,3
$ # Print... (1 Reply)
Hi,
I'm trying to create an XML sitemap of our dynamic ecommerce sites SEO Friendly URLs and am trying to create the initial page listing.
I have a CSV file that looks like the following and need duplicate the lines based on a value which needs calculating.
... (2 Replies)
Hi,
I have an issue to combine multiple lines of a file. I have records as below.
Fields are delimited by TAB. Each lines are ending with a new line char (\n)
Input
--------
ABC 123456 abcde 987
890456 7890 xyz
ght gtuv
ABC 5tyin 1234 789
ghty kuio
ABC ghty jind 1234
678 ght
... (8 Replies)
I want to use awk to split fields and put them into a file
but I don't know the number of fields
for example, in the following line
Ports: 22/filtered/tcp//ssh///, 53/open/tcp//tcpwrapped///, 111/filtered/tcp//rpcbind///, 543/filtered/tcp//klogin///, 544/filtered/tcp//kshell///,... (3 Replies)
I can't decide if I should use AWK or PERL after pouring over these forums for hours today I decided I'd post something and see if I couldn't get some advice.
I've got a text file full of hundreds of events in this format:
Record Number : 1
Records in Seq : ... (3 Replies)
Hi
I have a file as below
<field1> <field2> <field3> ... <field_num1> <field_num2>
Trying to sort based on difference of <field_num1> and <field_num2> in desceding order and print all fields.
I tried this and it doesn't sort on the difference field .. Appreciate your help.
cat... (9 Replies)
Hi Folks,
I have a file with fields as follows which has last field in multiple lines. I would like to combine a line which has three fields with single field line for as shown in expected output. Please help.
INPUT
hname01 windows appnamec1eda_p1, ... (5 Replies)
In the awk below, what I am attempting to do is check each line in the tab-delimeted input, which has ~20 lines in it, for a keyword
SVTYPE=Fusion. If the keyword is found I am splitting $3 using the . (dot) and reading the portion before and after the dot in an array a.
If it does have that... (12 Replies)
In the awk below I am trying to print the entire line, along with the header row, if $2 is SNV or MNV or INDEL. If that condition is met or is true, and $3 is less than or equal to 0.05, then in $7 the sub pattern :GMAF= is found and the value after the = sign is checked. If that value is less than... (0 Replies)
Discussion started by: cmccabe
0 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)