Is there a command that sets a variable length?
I have a input of a variable length field but my output for that field needs to be set to 32 char.
Is there such a command?
I am on a sun box running ksh
Thanks (2 Replies)
Hi
How to sort a fixed length file on a given char range and just display the duplicates.
I did search for man sort to find any option but could find any.,something similar to cut -c 1-5,25-35.
I have alternate way of doing this by using combination of cut,awk. but this
creates extra temp... (6 Replies)
Hi Unix Champs,
I want to awk on a fixed length file.
Instead if the file was a delimited file, then I could have used -F and then could have easily done manipulation on the fields.
How do i do the same in case of fixed length file?
Thanks in Advance.
Regards. (7 Replies)
Hi,
Can we join two fixed length files in Unix using JOIN command? Is there any other command to accomplish the same?
Thanks,
G.Harikrishnan (6 Replies)
OK I am somewhat new to UNIX programming please see what you can do to help.
I have a flat file that is a fixed length file containing different records based on the 1st character of each line. The 1st number at the beginning of the line is the record number, in this case it's record #1.
I... (3 Replies)
Very, very new to unix scripting and have a unique situation. I have a file of records that contain 3 records types:
(H)eader Records
(D)etail Records
(T)railer Records
The Detail records are 82 bytes in length which is perfect. The Header and Trailer records sometimes are 82 bytes in... (3 Replies)
Hi,
Can anyone help with a effective solution ?
I need to change a variable length text field (between 1 - 18 characters) to a fixed length text of 18 characters with the unused portion, at the end, filled with spaces.
The text field is actually field 10 of a .csv file however I could cut... (7 Replies)
How do I extract values in a few columns in a row of a fixed length file?
If there are 8 columns and I need to extract values of 2nd,4th and 6 th columns, how do i do that? I used cut command, this I used only for one column. How do I do it more than one column?
The below command will give... (1 Reply)
Hi,
I have a text file with sample records as
CASE ID: 20170218881083
Original presentment record for ARN not found
for Re-presentment
I want to extract the 23 digit number from this file. I thought of using grep but initially couldn't extract the required number. However, after... (16 Replies)
Discussion started by: dsid
16 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)