Hi Friends,
Following is an output of a script
OPWQERIUTYKLSADFJHGXZNMCVBWQOPERIUTYKLSADFJHGXZNMCVB
I want to replace above string's 11 to 17 character by ******* (7 stars)
How can it be done?
Please somebody guide me. (6 Replies)
This is the code:
while test 1 -eq 1
do
read a
$a
if test $a = stop
then
break
fi
done
I read a command on every loop an execute it.
I check if the string equals the word stop to end the loop,but it say that I gave too many arguments to test.
For example echo hello.
Now the... (1 Reply)
Hey,
I'm currently getting into some kernel module progamming. As a little exercise I want to read the headers out of an ELF file. My code is very simple, here is the important part:
struct file *fp;
/* ... */
fp = filp_open("some/file/on/my/pc", O_RDONLY, 0);
if(fp == NULL) {
... (15 Replies)
Hello, Unix-forums!
My problem:
read -p "Enter any number, please" number
sleep 1
echo $number | tr -d 0-9
test -z $number && echo "Thank you" || echo "This is not a number"Test always displays "This is not a number". It doesn't matter if I entered a or 1.
But if I order
echo... (2 Replies)
sed -e "s// /g" old.txt > new.txt
While I do know some control characters need to be escaped, can normal characters also be escaped and still work the same way? Basically I do not know all control characters that have a special meaning, for example, ?, ., % have a meaning and have to be escaped... (11 Replies)
I am trying to find a specific set of characters in a long file. I only want to find the characters in column 265 for 4 bytes.
Is there a search for that? I tried cut but couldn't get it to work.
Ex. I want to find '9999' in column 265 for 4 bytes. If it is in there, I want it to print... (12 Replies)
Hi all, I need help.
I have an input text file (input.txt) like this:
21 GTGCAACACCGTCTTGAGAGG 50
21 GACCGAGACAGAATGAAAATC 73
21 CGGGTCTGTAGTAGCAAACGC 108
21 CGAAAAATGAACCCCTTTATC 220
21 CGTGATCCTGTTGAAGGGTCG 259
Now I need to count A/T/G/C numbers at each character location in column... (2 Replies)
Good afternoon,
I am tearing hair out over this. It should be so simple. I have an if statement to evaluate whether or not replication is working. I am testing variables from mysql to see if they are both "Yes". I have put some echo statements in to see how far the code proceeds. It always... (6 Replies)
Hi,
I want to do caseless string comparision using test command
for eg: Ind_f="y"
test "$Ind_f" == "y|Y"
i tried , ** , nothing worked.
any thoughts on how to do case insensitive string comparison using test command without converting to any particular case using typeset or tr? (8 Replies)
Discussion started by: Kulasekar
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)