Hi,

May I know, if a pipe separated File is large, what is the best method to calculate the unique row count of 3rd column and get a list of unique value of the 3rdcolum?

Thanks in advance!

read the file line by line and use a hash to get the unique values of the 3rd column.

Could you kindly explain with one simple example.

Maybe realy simple:

cat $file|awk -F\| '{print $3}'|sort -u

(I think some awk guru can do it with less commands)...

I saw to late you meant perl.. sorry

I can handle with cut, sort -u, and wc commands.

But looking for perl methods!

read the file
split the record
use the third field
populate in a hash => this would maintain uniqueness
when displaying use sort keys %hash