10 More Discussions You Might Find Interesting
1. UNIX for Beginners Questions & Answers
Hi All,
I want to write a bash script in which a function needs to be called based on its first character in a supplied string. eg function "j" should be called when "jab" or "jgh" or "j" .... etc is hit. I have used complete -F in below script, however here function is invoked... (1 Reply)
Discussion started by: temp.sha
1 Replies
2. Shell Programming and Scripting
In unix systems I can call `file` to return me the file type.
file cel.vik
$ cel.vik: ASCII text
How can I append additional information when I create a file such that when I call `file` it returns me that additional information. (2 Replies)
Discussion started by: kristinu
2 Replies
3. Shell Programming and Scripting
Hello
Is it possible to redirect standard input into a file in an interactive script like we do for standard out and input using &2 and &1.
Enter source :
hi
Enter destination :
bye
In the log i can see like this when I am using script.sh 2>&1 | tee file
Enter source :
Enter... (3 Replies)
Discussion started by: ningy
3 Replies
4. Shell Programming and Scripting
I have a log file which has records with hung thread information/error
I need to find out hung thread from log file greater than timestamp supplied.
00000026 ThreadMonitor W WSVR0605W: Thread "WebContainer : 1" (00000027) has been active for 701879 milliseconds and may be hung. There is/are... (6 Replies)
Discussion started by: megh
6 Replies
5. Programming
I have written this C++ program and I am using getopt_long and want to chech when the user supplies the arguments so that I can put a default or otherwise.
Currently I am using hasargv or Pc.get_string("key",s), Pc.get_real("key",s), etc
to detect whether the user supplied a value.
For... (3 Replies)
Discussion started by: kristinu
3 Replies
6. Programming
I have written this C++ program and I am using getopt_long (2 Replies)
Discussion started by: kristinu
2 Replies
7. UNIX for Dummies Questions & Answers
Hi,
I have a file that contains >4000 inode numbers. Each inode number is on separate row. I'd like to delete all this files. Any idea how could I do it?
Thank you.
Andrej (3 Replies)
Discussion started by: andrejm
3 Replies
8. Shell Programming and Scripting
I shoe here the start of a csh script I have written. I am trying to write some code to check the arguments and if the arguments don't match the tags, I will abort and display an error.
For example using
./script.csh -r=10/20.30/40 -xyz=2/3/4
will give an error as the -xyz tag doea not... (24 Replies)
Discussion started by: kristinu
24 Replies
9. Homework & Coursework Questions
Use and complete the template provided. The entire template must be completed. If you don't, your post may be deleted!
1. The problem statement, all variables and given/known data:
Your script must check for the correct number of arguments (one argument). If somebody tries to invoke the... (1 Reply)
Discussion started by: brooksie91
1 Replies
10. Shell Programming and Scripting
I have a program to scan the log files and I want to pipe the output to 'less'.
I want to create an alias such that following are equivalent
scanlog chunky.lst = /udd/n2man/utils/scanlog chunky.lst|less
where chunky is user supplied file which can change.
Is this possible as an alias or... (1 Reply)
Discussion started by: ospreyeagle
1 Replies
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)
