[R] Fast way to determine number of lines in a file

hadley wickham h.wickham at gmail.com
Tue Feb 9 15:47:03 CET 2010


> I was looking for a fast line counter as well a while ago and ended up
> writing a small function in R:
>
>  countLines() in the R.utils package
>
> At least at the time, it was faster than readLines() [for unknown
> reasons].  It is also more memory efficient.  It supports connections.
>  I don't think it beats a system call to 'wc', though.  When there
> will be a faster solution available, it'll be calling that instead.
> It does not avoid reading the file twice.

Perfect - exactly what I was looking for.

Thanks!

Hadley

-- 
http://had.co.nz/



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