Tricky part is that commas may be present within the field (that's why the quotes)
Yoda's solution will not work for files that have more than 6 columns, or files that have commas in the last two fields. E.g. file
I would suggest the following approach:
1. protect the comma within quotes by substituting it with some character
2. get rid of the 4th field
3. substitute the protect character with comma to get back the original
Try this solution:
Code:
sed 's/"\([^,]*\),\([^,]*\)"/"\1\x1C\2"/g' file | awk -F, '{$4 = ""}1' OFS=, | sed 's/,,/,/g ; s/\x1C/,/g'
Explanation:
Code:
sed 's/"\([^,]*\),\([^,]*\)"/"\1\x1C\2"/g' file # replace commas within quotes with \x1C (non-ascii character unlikely to be in your file)
awk -F, '{$4 = ""}1' OFS=, # strip the fourth field -- now it is safe to split them by commas
sed 's/,,/,/g ; s/\x1C/,/g' # get rid of double commas and replace \x1C back to comma for quoted commas
Hi
Can anyone what I am doing wrong while using cut command.
for f in *.log
do
logfilename=$f
Log "Log file Name: $logfilename"
logfile1=`basename $logfilename .log`
flength=${#logfile1}
Log "file length $flength"
from_length=$(($flength - 15))
Log "from... (2 Replies)
Hi,
I need a help with cut/awk command. I need to get certain values from a string provided. For example: i have a config file with below mentioned details
oracle="user=name"/"pass/word"@databasename.
I have used a command var1=`grep -w oracle sample.cfg | cut -d"=" -f2 | cut -d"/" -f1`.
... (10 Replies)
Hi Friends,
I have a file1
i want to retrieve only the fields which have DEP,CITY,TRANS as headers in other file.
Output:
I want to give the input as DEP,CITY,TRANS column names to get the output.
i used cut command .. but if i have 300 fileds it is more difficult to... (4 Replies)
Hi,
I have to display the value 16 present in "lcpu=16" which is the output of a command
# vmstat
System configuration: lcpu=16 mem=4096MB
I used as
# hdtype=`vmstat | grep "lcpu" | awk -F "=" '{print $2}'`
# echo $hdtype
16 mem
But I need to display only 16..
Am doing... (3 Replies)
hay
i am trying to get JUST the PID from the ps command.
my command line is:
ps -ef | grep "mintty" | cut -d' ' -f2
but i get an empty line. i assume that the delimiter is not just one space character, but can't figure out what should i do in order to do that.
i know i can use awk or cut... (8 Replies)
Hi,
My aim is to get the md5 hash of a file and store it in a variable.
var1="md5sum file1"
$var1
The above outputs fine but also contains the filename, so somthing like this 243ASsf25 file1
i just need to get the first part and put it into a variable.
var1="md5sum file1"... (5 Replies)
I'm a complete beginner in UNIX (and not a computer science student either), just undergoing a tutoring course. Trying to replicate the instructions on my own I directed output of the ls listing command (lists all files of my home directory ) to My_dir.tsv file (see the screenshot) to make use of... (9 Replies)
Hi Everyone,
I have a very simple problem and i am stuck in that from last 8 days. I tried many attempts, googled my query but all in vain.
I have a text file named "test.txt"
In that suppose i have contents like:
Java:
1 Object oriented programming language
2 Concepts of Abstraction... (5 Replies)
Hi,
I would like use the output of my cut command as a variable in my following awk command. Here's what I've written.
cut -f1 info.txt | awk -v i=xargs -F'' '{if($6 == $i) print $20}' summary.txt
Where obviously the 'xargs' doesn't do what I want. How can I pass my cut result to my awk... (3 Replies)
Discussion started by: heyooo
3 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)