I currently use this construction to check whether a certain program is installed:
Is this method recommended? Is this an effective method, ie sufficiently robust for other examples, such as gcc, php, perl etc? Are there any caveats to this? The snippet is run as part of a script as root.
Hi,
How can I know the perl interpreter is installed in the system?
When I type 'find / -name perl -print 2>/dev/null', there is 6 lines listing:
/usr/local/bin/perl
/usr/bin/perl
/usr/lib/perl-5.8.0/bin/perl
/usr/opt/IAFW310/PERL/perl
/usr/opt/IAFW310/PERL/t/perl... (3 Replies)
I want to check which databases are installed on my FreeBSD installation. This is what I did: pkg_info | grep mysql
How do I check all in one go whether also sqlite, postgresql, firebird is installed?
Thanks in advance (3 Replies)
I develop a unix program in HPUX
I want to package my program
to install on HPUX in some dierctory folder
like /user/local/sbin/xxx
and preinstall some software before install my program
package like xxx.depot
how can i do it, have any tools like use setupfactory tools in windows
... (4 Replies)
Hi all,
I'm running a simulator and I'm noticing an slow increase in memory for long simulations such that the simulation has to end because of a lack of memory. A colleague of mine ran Valgrind memcheck and reported that nothing of interest was reported other than known mem leaks. My advisor... (2 Replies)
Hi,
I am new to linux, and i want to know which mysql dbd is installed on linux,
what is the command to check this.
bash-2.05$ uname -a
Linux SURINT01 2.4.7-10 #1 Thu Sep 6 17:27:27 EDT 2001 i686 unknown
Thanks
Prakash GR (6 Replies)
Hi,
For the below problem, awk script is needed..
input file :
jill
jack
jill
jill
jack
jill
jack
jill
Required:
here,
i need to check from first line.
reference is jack. jill need to verified with next line jack. if found print
jill & jack combination hill1
jack & jill &... (0 Replies)
Hi
I would like to ask in ubuntu or linux on how to list all my package or software the i installed via source code( compile installed in dir default is /usr/local) just like i solaris in which if you installed a package in ur choosing default root installation dir you can just issue a command... (2 Replies)
Hi Guys,
Good morning! I have a file which looks something like this:
Command was launched from partition 0.
------------------------------------------------
Executing command in server server3
Thu Jan 12 11:10:39 EET 2012
------------------------------------------------... (3 Replies)
Hi,
I have a requirement where I need to combine two lines in a file based on first character of each line in a file.
Please find the sample content of the file below:
_______________________
5, jaya, male, 4-5-90, single
smart
6, prakash, male, 5-4-84, married
fair
7, raghavi, female,... (12 Replies)
Hello Forum,
I'm issuing a one line bash command to look for the version of an installed application and saving the result to a variable like so:
APP=application --version
But if the application is not installed I want to return to my variable that the Application is not installed. So I'm... (2 Replies)
Discussion started by: greavette
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)