Just for something kind of different, you can play fun games with the input record seperator and end up with something like 
sub IRS_chunky {
    my($buf, $leftover, @lines);
    local $/ = \10240;
    open(FILE, "totalfoo");
    while( $buf = <FILE> ) {
       $buf = $leftover.$buf;
       @lines = split(/\n/, $buf);
       $leftover = ($buf !~ /\n$/) ? pop @lines : "";
       foreach (@lines) { }
    }
    
    close(FILE);
}

[download]
which is comparable, on my machine, to chunky.

My real question, though, is what kind of machines are you running this on? My benchmark results are completely different than yours. Having run this three times on a Sun Ultra 5 on a file that is approx 500,000 lines and 24Mb in size from my local IDE drive, my results were pretty consistently like this 

perl test_read.pl
Benchmark: timing 10 iterations of Chunky IRS, chunk, linebyline...
Chunky IRS: 41 wallclock secs (31.31 usr +  3.71 sys = 35.02 CPU)
     chunk: 40 wallclock secs (31.00 usr +  3.81 sys = 34.81 CPU)
linebyline: 27 wallclock secs (17.67 usr +  2.47 sys = 20.14 CPU)

[download]
The code I used was identical to the earlier post, with the subroutine I wrote added. Using perl-5.6 generated the same basic results, plus or minus 1 for each stat. I am now somewhat confused. Is this a difference in the way Solaris uses its buffers? What platform/OS were the original tests run on?

mikfire

In reply to RE: Re: read X number of lines? by mikfire
in thread read X number of lines? by eduardo

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