How to compare and sort 2 csv's to show difference

Question

Hi I have 2 csv\'s in the following format, (basically a list of email and the number of times we have been emailed by that sender):

file1.csv

Email,Val         


        

Answer 1

if you want to keep the order

awk to the rescue!

$ awk  'BEGIN   {FS=OFS=","}
        NR==FNR {a[$1]=$2; next} 
        FNR==1  {print $1,$2"1",a[$1]"2"; next} 
                {print $1,$2,a[$1]}' file2 file1

Email,Value1,Value2
email1@email.com,2,3
email2@email.com,4,6
email3@email.com,1,8
email4@email.com,6,2

note the order of files...