please send the logic or program to find the matching characters between two strings
for ex string1 :abc
string2 :adc
no .of matching characters is 2(a,c) (9 Replies)
how do i check if the first character is a parenthese in pattern matching?
if ] obviously doesnt work. How do I use it to compare so it doesnt try to use it to group. (5 Replies)
Hi there,
I have a file with lines like these:
0105:ffff0000:001b:01f4:25:434
0299:ffff0000:0009:01f4:2:319
02d2:ffff0000:000e:01f4:2:507
The above values are split up using ":" characters.
I would like capture each value, no matter what length.
Take for example the first line... (8 Replies)
Dear all,
I'm stuck on a certain problem regarding counting the number of characters in one line and then adjusting the number of characters of another line to this number.
This was my original input data:
@HWI-ST471_57:1:1:1231:2079/2... (4 Replies)
hi
i am writing a hangman script and am having trouble checking the correct letters against the word
i need the script to compare the word against the letters guessed that are correct so once all the letters within the word have been guessed it will alow me to create a wining senario
eg
... (3 Replies)
hi
i am writing a hangman script and am having trouble checking the correct letters against the word
i need the script to compare the word against the letters guessed that are correct so once all the letters within the word have been guessed it will alow me to create a wining senario
this must... (1 Reply)
I want to check where our programmers are using "delete" instead of "delete" in their C++ code:
grep -r delete *cpp | grep -v
However, this statement and variations thereof (escaping with backslash (\), single quotes ('), double quotes ("), accolades ({)) always lead to the following message:... (2 Replies)
I need to write an Unix script to report the number of SQL files in my home directory, ending with .sql . The script should, also, be checking whether there is a file with an underscore in its name. If that is the case, the underscore should be converted to a dash (‐); for example... (1 Reply)
hii all
i have a file a which contains some thing like this
strand smthg position
+ yyx 3020
- yyw 10,000
now i have another file (file2) which contains the data starting from 1 to n positions
i want to refer first file if + ... (4 Replies)
hi to all,
i am writing a simple file program in C which has to take a string of length n as input and match that input string with first n character of the line in file. if it does not match it has to compare with first n characters of next line. i am finding it difficult to know how exactly to... (2 Replies)
Discussion started by: ntrikoti
2 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)