hi,
i was trying to club to test condition with if.
if -o ; then
it is giving me error message, i wanted to ask how can we check two condtions with one if. (1 Reply)
1. echo "abc 123 abc" | sed 's/*/X/'
yields -
X 123 abc
Does this mean the "*" operator matches ONLY the first and
the entire token - "abc" and replaces with "X" ?
2. echo "123 abc" | sed 's/*/X/'
yields -
X123 abc
What does this indicate about the "*" operator ?? (7 Replies)
Hi
I want to group
like this but syntactic is not right ...
Thanks
if
Like this below does not work properly ..
if
then
:
else
usage
exit 1
fi (5 Replies)
Hi,
Please clear the 2 questions,
2 Questions,
1) Why the new as a operator? Is there any special reason why it can't be a function like malloc?
2) How are we considering sizeof(),new are as a opearartors? I know + - * / -> , . etc.. are operators, which criteria satisfied by sizeof()... (4 Replies)
All,
THe below is my script , when i use this i am getting nothing . could any one help me to know what is the use of the << operator below
su - $8 << supo
echo "exportsph $2 $1 $3 $4"
exportsph $2 $1 $3 $4
supo
i also tried as individual command su - userid << supo , when i do... (3 Replies)
Hi,
I have the below script executed
arg="dir"
if "$arg" = "dir"
then
echo "true"
else
echo "false"
fi
Please let me know what happens in the if command.
My output is:
dir: dir: No such file or directory
false
which is not the desired output.
When i used test command... (1 Reply)
I wrote a little students management program using structs, and when I try to compile it, an error appears:
luke@luke-desktop:~/Desktop/ProgII$ g++ recStudents.cc
recStudents.cc: In function ‘void add(TList&, Tstudent)':
recStudents.cc:114: error: no match for ‘operator' in ‘Slist'Here... (2 Replies)
im new to bash scripting and im just using online tutorials and trial and error. i wanted to write a script to read numbers from a file and find their sum:
#!/bin/bash
theSum=0
for line in $(cat numbers.txt)
do
let "theSum = theSum + $line"
echo "$line"
done
echo "The sum is... (3 Replies)
hi,
I got a requirement to change existing script like below to search additional pattern "DB select". i tried using \| opearator but it is not working :(. Below is the existing code
echo $(cat ${1} |sed -n '/Error in/ {
N
N
N
/Too many/ {
p
... (5 Replies)
Discussion started by: shyamxtasy
5 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)