Shell Programming and Scripting

 
file=file1.csv
        if test -s "$file"
        then
                cat $file|while read line
                do
                        a=`cat $line | awk '{print $1}' `
                        b=`cat $line | awk '{print $2}' `
                        rate=`grep -i "$b" file2.csv`
                        echo "$a, \"$rate\"" >> output.csv
                done
        else
                echo "no need of correction."
        exit 0
        fi

a=`cat $line | awk '{print $1}' `
b=`cat $line | awk '{print $2}' `

a=`cat $line | awk -F"," '{print $1}' `
b=`cat $line | awk -F"," '{print $2}' `

file=file1.csv
        if test -s "$file"
        then
                while read line
                do
                        a=$(echo $line | awk -F"," '{print $1}' )
                        b=$(echo $line | awk -F"," '{print $2}' )
                        rate=$(grep -i "$b" file2.csv)
                        echo "$a, \"$rate\"" >> output.csv
                done < $file
        else
                echo "no need of correction."
        exit 0
        fi

awk '
BEGIN { FS = OFS = "," }
FNR == NR {
        # Set up translation table indexed by string converted to lower case.
        t[tolower($1)] = $1
        next
}
{       if((l = tolower($2)) in t)
                # We found a case insensitive match, make the translation.
                $2 = t[l]
        print   # Print the original or updated record.
}' file2.csv file1.csv . output.csv