# Edit column/value in CSV-file # append the string '000' to the third column awk 'BEGIN{FS=OFS=","} {$3=$3"000"; print}' file1.csv # add 1000 to the existing value of the third column/value (for numbers, otherwise it will be replaced) awk 'BEGIN{FS=OFS=","} {$3=$3+"1000"; print}' file1.csv # or awk 'BEGIN{FS=OFS=","} {$3+="1000"; print}' file1.csv # if column 1 is the same as column 2, add/edit column 3 and make it read 'These are the same' awk 'BEGIN{FS=OFS=","} {if ($1 == $2); $3="These are the same"; print}' file1.csv