Don't forget cut, sort and uniq. If you have a big csv file, you could strip out all duplicate values in the fourth fields: cut -d , -f 4 [file] | sort | uniq

Don't forget cut, sort and uniq. If you have a big csv file, you could strip out all duplicate values in the fourth fields: cut -d , -f 4 [file] | sort | uniq > values.txt You could then grep out the records with the particular values of interest. If a file is too big for an editor, you can still see the record structure with head.