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awk compare column n replace with in one file

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# 1  
Old 11-10-2012
Linux awk compare column n replace with in one file
hi Friends
need to compare columns in one file where the data looks like below
Code:
laptop,IBM
phone,samsung
car,rental
user1,laptop
user2,laptop
user3,phone

want to get output as
Code:
laptop,IBM
phone,samsung
car,rental
user1,IBM
user2,IBM
user3,samsung

need to seach $2 in array of $1 and if found print the $2 of the found...
if not print as it is
Last edited by Scott; 11-10-2012 at 09:20 AM.. Reason: Code tags
# 2  
Old 11-10-2012
With assumptions:
Code:
awk -F, '$2 in a{$2=a[$2]}{a[$1]=$2}1' OFS=, file

This User Gave Thanks to elixir_sinari For This Post:
arun1401
# 3  
Old 11-10-2012
Hi

Code:
awk -F, 'NR==FNR{a[$1]=$2;next}{$2=a[$2]?a[$2]:$2}1' OFS=,  file file

Guru.
This User Gave Thanks to guruprasadpr For This Post:
arun1401
# 4  
Old 11-10-2012
Quote:
Originally Posted by elixir_sinari
With assumptions:
Code:
awk -F, '$2 in a{$2=a[$2]}{a[$1]=$2}1' OFS=, file

thanks for that,i tried all this while to understand the idea. still coudnt
# 5  
Old 11-10-2012
awkishly speaking:
Code:
awk -F, '                # set "," as field separator
$2 in a{$2=a[$2]}        # if field 2 is an array a key set field 2 to array a value for field 2 key
{a[$1]=$2}1              # store field 2 in array a value for field 1 key and print line
' OFS=, file             # use "," as output field separator, use file as input

This User Gave Thanks to rdrtx1 For This Post:
arun1401
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