Estimate the number of rows in an Excel file quickly

Question

I've got a Ruby + Merb webapp that needs to quickly estimate (or count exactly) how many row a spreadsheet has. It accepts every format that the roo library supports, including .xls, .xlsx, .ods, and text-based formats like CSV and TSV.

CSV/TSV is easy and fast:

`cat #{filepath} | dos2unix | wc -l`.to_i

However, using the roo library can be very slow for large files:

e = Excel.new(filepath)
e.last_row

My experience with Excel file formats is nil, so I'm appealing to the S.O. Masses: how might I try to estimate the number of rows an XLS, XLSX, or ODS file contains using only Ruby and/or standard UNIX programs? My goal is to be able to handle 5mb files in under 1.5 seconds (give or take on various hardware).

Answer 1

Is this helpful? http://www.weheartcode.com/2007/10/05/reading-an-excel-file-with-ruby/

Answer 2

I'm working with spreadsheet gem, give it a shot.