Anyone know where I can get started in C++ programming in unix?
Any good free tutorials or websites to start at?
I am okay in unix scripting but have never done c programming of any sort...
What are the main advantages of using C++ ? (2 Replies)
Recently installed a custom PC with Solaris 10 u4, kernelpatch 127112-10.
I was going to use this box as a NAT router using ipf. ipf however caused the box to panic multiple times. This in turn lead to a couple other issues that I would like some input of.
- None of the panic's i've... (0 Replies)
hi guys,
i have a DEl xps laptop cor 2 duo 2.2
i have vista installed on it
i want to install a dual Boot UNIX on it..
can some one guide me ...cause i m tottaly new to UNIX
i want to install unix on that laptop along with Vista....
thx
any help would be deeply appreciated
(sorry if i... (5 Replies)
Hey Guys,
I am creating a bash script on my freeBSD box, the script should basically ask the user to enter a username and domain. The script will take this information and basically append alot of information to config files so the user can receive email from that domain and create a web site at... (1 Reply)
I need to write a script to test a nsort c program. I have written 8 .txt files with different cases. Also 8 .txt files with expected outcome. The shell I have written always "test pass" for the first case but always "fail" for the rest... Here is a portion of my code (as I still don't know how to... (5 Replies)
Hello, I have a block of code (XML) that I would like to grep for certain information. The basic format of the XML is the following repeated a few hundred times, each time with a unique ID:
<Identifier ID="A" NAME="John Doe" AGE="32 Years" FAMILY="4" SEX="MALE"></Identfier>
I would like to... (6 Replies)
Could anyone explain why I am having trouble surfing the internet with both firefox and konqueror? Chromium seems to be the only browser that will work. I tried to create a new profile with firefox and that didn't work either. I can ping things just fine, I can download stuff with wget, I can ssh... (6 Replies)
I am facing a problem and I would be grateful if you can help me :wall:
I have a list of words like
And I have a datafile like
the box of
the box of tissues out of
of tissues out of
the book, the
the book, the pen and the
the pen and the
I want to find Patterns of “x.*x” where... (2 Replies)
I am experimenting with some scripting as a way to learn more about it. I have a simple script that calls two other scripts. Each script echos some stuff to prove it ran and then sets a simple variable and exports it.
I cannot get one of the variables to display back in the main calling script... (2 Replies)
i have windows 8 host on Dell Laptop
vmware 9
redhat 7.2 iso downloaded through redhat official site
after installation on vm it only boots into text dont show graphics
Please guide:( (1 Reply)
Discussion started by: hananabbas
1 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)