Hi,
I'm trying to write a command that backs up certain files into my current directory and adds a prefix to the backed up file name. I realise this can be done in a script by specifying each individual file but would like to know if it can be done on one line and made an alias.
I have the... (5 Replies)
I have many files that have "inputstring" somewhere in their filename (without the quotes), and I want to rename them all so that "inputstring" is replaced with "newstring". And I also want to specify arbitrary text for "inputstring" and "newstring" so that I can call the scripts that does this... (6 Replies)
I have a large list of filenames from an Excel sheet, which I then translate into a simple text file. I'd like to use this list, which contains various file extensions , to archive these files and then remove them recursively through multiple directories and subdirectories. So far, it looks like... (5 Replies)
Hello,
I am trying to write a bash shell script that does the following:
1.Finds all *.txt files within my directory of interest
2. reads each of the files (25 files) one by one (tab-delimited format and have the same data format)
3. skips the first 10 rows of the file
4. extracts and... (4 Replies)
Howdy,
I am trying to search for a string within a directory, and then return the filename only, without the directory itself.
I am using korn shell and the command
x=$(find /XXXXX/XXXXX/XXXXX/I2 -exec grep -c "$line" {} /dev/null \;)
which returns the directory and the filename:
... (4 Replies)
Hi there,
I am having trouble with a script I have written, which is designed to search through a directory for a header and payload file, retrieve a string from both filenames, compare this string and if it matches make a backup of the two files then move them to a different directory for... (1 Reply)
Hi,
I have a file containing list of strings like
i:
Pink
Yellow
Green
and I have file having list of file names in a directory
j :
a
b
c
d
Where j contains of a ,b,c,d are as follows
a:
Pink (3 Replies)
Hi,
Is there any way to do a cat * where it shows the name of each file in the process? Similar to what more does below?
$ more ?.sql
::::::::::::::
1.sql
::::::::::::::
set linesize 200
select db_unique_name,
cast(
from_tz(
cast(... (5 Replies)
Hello,
I tried different solutions given in various linux portals but no luck..
The directory consists of files with no-extension.
Each file has only one line. I need to add each filename to the top of each file so eventually each file will have two rows.
Filenames have spaces between words... (6 Replies)
Discussion started by: baris35
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)