Dear All,
I am new to Unix and need your help. I am trying to write b-shell script which will return substr of some variable like this
d="asdfg"
return Substr(d,1,5).
Please help (5 Replies)
What is the more efficient way to do this (awk only and default FS) ?
$ echo "jefe@alm"|awk '{pos = index($0, "@");printf ("USER: %s\n",substr ($0,1,pos-1))}'
USER: jefe
Thx in advance (2 Replies)
Hi,
My input file is
41;2;xxxx;yyyyy....
41;2;xxxx;yyyyy....
41;2;xxxx;yyyyy....
..
..
I need to change the second field value from 2 to 1. i.e.,
41;1;xxxx;yyyyy....
41;1;xxxx;yyyyy....
41;1;xxxx;yyyyy....
..
..
Thanks in advance. (9 Replies)
Hi,
I have a long string like,
aabab|bcbcbcbbc|defgh|paswd123 dedededede|efef|ghijklmn|paswd234 ghghghghgh|ijijii|klllkkk|paswd345 lmlmlmmm|nononononn|opopopopp|paswd456
This string is devided into one space between substrings. This substrings are,
aabab|bcbcbcbbc|defgh|paswd123... (6 Replies)
Hi I am trying to run this command in ksh ...its not working
$line="123356572867116w1671716"
actual_length = 16
cut_line=`awk 'BEGIN{print substr(ARGV,1,actual_length)}' "$line"`
the substr is not giving me an output
how can i make it done
can anyone hwlp me on this
cut_line=`awk... (2 Replies)
I have the following to find lines matching "COMPLETE" and extract parts of it using substr.
sed -n "/COMPLETE/p" 1.txt | awk 'BEGIN { FS = "\" } {printf"%s %s:%s \n", substr($3,17,3),substr($6,4,1), substr($7,4,1)}' | sort | uniq > temp.txt
Worked fine until the numbers in 2nd & 3rd substr... (5 Replies)
I have a command like this:
listdb ID923 -l |gawk '{if (substr($0,37,1)==1 && NR == 3)print "YES" else if (substr ($0,37,1)==0 && NR == 3) print "NO"}'
This syntax doesn't work. But I was able to get this to work:
listdb ID923 -l |gawk '{if (substr($0,37,1)==1 && NR == 3)print "YES"}'
... (4 Replies)
Hi,
I am trying to print last few characters of a string but unable to get the correct output through awk substr.
The length of the string and the number of characters to be printed varies day to day.
For example,To print 1234 from abcdef1234, i will be given 2 strings,string1(for example... (4 Replies)
awk '/^>/{id=$0;next}length>=7 { print id, "\n"$0}' Test.txt
Can I use substr to achieve the same task?
Thanks! (8 Replies)
Discussion started by: Xterra
8 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)