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Delete unique rows - optimize script

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# 1  
Old 09-16-2012
Delete unique rows - optimize script
Hi all,

I have the following input - the unique row key is 1st column

Code:
cat file.txt
 
[4] A response
[1] C request
[1] C response
[3] D request
[2] C request
[2] C response
[5] E request

The desired output should be

Code:
[1] C request
[1] C response
[2] C request
[2] C response

Now i have implemented the below loop which does work but when the input file is bigger than 300 mb in size the whole process of removing the non-pairs rows takes ages since it needs to scan the whole file in a loop.

Code:
#/bin/bash
req=$(mktemp)
res=$(mktemp)
new=$(mktemp)
tmp=$(mktemp)
grep request  $1 > $req
grep response $1 > $res
for id in `cat $req | awk '{ print $1}'` 
do    
    id=$(echo $id | tr -d "[]")
    grep "$id" $res > $tmp 
    if [[ -s $tmp ]]
    then
 grep "$id" $req >> $new
 cat $tmp >> $new 
    fi
done
mv $new $2
rm $req $res $tmp

Any idea how i can optimize/ do it differently to remove the unique rows as per above example in order to speed up the process?
# 2  
Old 09-16-2012
Code:
[4] A response
[1] C request
[1] C response
[3] D request
[2] C request
[2] C response
[5] E request

I think you want all the response items as per your request?????

Code:
#/bin/bash
req=$(mktemp)
res=$(mktemp)
new=$(mktemp)
tmp=$(mktemp)
grep request  $1 | sort | uniq > $req   #to get unique request items.
grep response $1 > $res
for id in "$(cat $req | awk '{ print $1,$2}')" # Get whole part as - [1] C,[2] C -- Makes it more unique
do    
    #id=$(echo $id | tr -d "[]")   # I think its better to search with [1] C to get more unique results.. that's why commented this.
    grep "$id" $res > $tmp 
    if [[ -s $tmp ]]
    then
 grep "$id" $req >> $new
 cat $tmp >> $new 
    fi
done
mv $new $2
rm $req $res $tmp

Last edited by pamu; 09-16-2012 at 04:58 AM..
# 3  
Old 09-16-2012
Thanks for quick reply.

I want only request/response pairs. IF there is only request or response without any associated pair then it should be removed.

Cheers.
# 4  
Old 09-16-2012
Quote:
Originally Posted by varu0612
I want only request/response pairs. IF there is only request or response without any associated pair then it should be removed.
Have you tried my suggestions..?
# 5  
Old 09-16-2012
Yes i did - but there is no difference since is the same logic, for each row it needs to scan the whole file in a loop.

I think i'll gain more if i find a way to scan the file once and delete the unique rows/ lines, something like this....

check for key "[1] request" or "[1] response" and if you don't find the pair delete it..
# 6  
Old 09-16-2012
Quote:
Originally Posted by varu0612
check for key "[1] request" or "[1] response" and if you don't find the pair delete it..
Try this..

Code:
sort file | awk '/request/ {s=$0;p=$1;getline} {if ($0 ~ /response/ && $1 == p) { print s"\n"$0 }}'

This User Gave Thanks to pamu For This Post:
varu0612
# 7  
Old 09-16-2012
One way :
Code:
~/unix.com$ awk 'NR==FNR{A[$1]++;next}A[$1]==2' file.txt file.txt

This User Gave Thanks to tukuyomi For This Post:
varu0612
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