If you want to read and write to a file have you tried Tie::File? Sample of code using IO::All module which includes the methods of Tie::File.

Hi, have you tried using Tie::File to edit a >2GB file ? Tie::File is slow, to write a 1mb file 137.506 seconds, versus 0.197 seconds without it

That would make a 2GB file take 3+days Tie::File is super slow, to print the 20/40 millionth lines in a 3GB file takes more than 30-40 minutes , versus 12 seconds without it