Hello
would appreciate if somebody can post a bash script that checks if the first character of the given string is equal to, say, "a"
thnx in advance (2 Replies)
can anyone tell me why this doesn't work? I've been trying to play with character classes and I seem to be missing something here..!
echo "./comparecdna.summary" | awk '/^compare+]summary$/' # returns nothing
echo "./compare_cdna.summary" | awk '/^compare_+]summary$/' # returns nothing
echo... (5 Replies)
Hi!
If I want to extract a character from a specific position of a string, I can use ${string:1:1} (if I want character at the position 1). How can I do the same thing, when the number of position is contained in the variable? ${string:$var:1}doesn't work, unfortunately.
Thanks in advance. (2 Replies)
In bash, how can one remove the last character of a string? In perl, the chop function would remove the last character. However, I do not know how to do the same job in bash.
Many thanks in advance. (12 Replies)
Hi I need a bash script that can search through a text file and when it finds 'FSS1206' I need to put a Letter F 100 spaces after the second instance of FSS1206
The format is the same throughout the file I need to repeat this on every time it finds the second 'FSS1206' in the file
I have... (0 Replies)
Hi, I want to check out a word in the text file and generate a clear report for me to see...
The text file content:
Content:
............
20120608:
20120608:
............
20120608:
..........
2012031201: , hime]
End of the file
My expected output is:
Full TXT:
manatsu
TXT:... (3 Replies)
I am writing a bash script that will find all references to the “Well_List” in the “Comp_File”.
I am filtering a Well_List that contains the following:
TEST_WELL_01
TEST_WELL_02
TEST_WELL_11
TEST_WELL_22
GOV_WELL_1
GOV_WELL_201
PUB_WELL_57
PUB_WELL_82
.
.
Comparison... (5 Replies)
Hello.
I have a string variable named L_TEMP to test a very simple filter.
L_TEMP="50AwL.|KWp9jk"
I want to insert a non printable character between K and W.
I have try this :
linux-g65k:~ # a='50AwL.|K'
linux-g65k:~ # b='Wp9jk'
linux-g65k:~ # L_TEMP="$a$'\x07'$b"
linux-g65k:~ # echo... (6 Replies)
Hi,
I am new in bash scripting. In my work, I provide support to several users and when I connect to their computers I use the same admin and password, so I am trying to create a script that will only ask me for the IP address and then connect to the computer without having me to type the user... (5 Replies)
Anybody have an explanation for why \s doesn't match ' ' in a character class? Here are 3 examples with the final example showing that \s in a character class (demonstrated by using egrep -o) fails:
\s works outside of class..
# echo " FOO " | egrep -o '\s+\s'
FOO
Here is a... (6 Replies)
Discussion started by: blackrageous
6 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)