count the number of filled cells in several columns

[helen...@gmail.com]

Hi all,

I neet to count the number of filled cells in a .txt file. It has four columns and 7580 rows, and they are separated by tabs. How can I get it? I can get the number of filled cells of one column, but I cannot get the number of filled cells in several columns. This is important because I need to know the number of shared columns per row.

I will appreciate your help,

Thank you very much in advance,