Count the number of lines in a file without reading entire file into memory?

Question

I\'m processing huge data files (millions of lines each).

Before I start processing I\'d like to get a count of the number of lines in the file, so I can then indic

Answer 1

You can read the last line only and see its number:

f = File.new('huge-file')
f.readlines[-1]
count = f.lineno