C:\test>dir 500MB.csv 31/07/2012 20:22 536,870,913 500MB.csv C:\test>wc -l 500MB.csv 8388608 500MB.csv [23:19:43.35] C:\test>perl -nle"$.==3 || $.==8e6 and next; print" 500MB.csv >nul [23:19:53.65] C:\test>