How can I set the file-read buffer size in Perl to optimize it for large files?

Question

I understand that both Java and Perl try quite hard to find a one-size-fits all default buffer size when reading in files, but I find their choices to be increasingly antiqu

Answer 1

I'm necroposting since this came up on this perlmonks thread

It's not possible to use setvbuf on perls using PerlIO, which the default since version 5.8.0. However, there is the PerlIO::buffersize module on CPAN that allows you to set the buffer size when opening a file:

    open my $fh, '<:buffersize(65536)', $filename;

IIRC, you could also set the default for any new files by using this at the beginning of your script:

    use open ':buffersize(65536)';