You might be interested in this benchmark. It dosn't do exactly what you want, but it demonstrates the huge speed differences.
#!/usr/bin/perl use Benchmark; use File::ReadBackwards; use strict; my $numlines =10; my $filename = 'talz.dat'; #some big file timethese(1000, { #################################################### filereadbackwards => sub { my @lines; my $line; my $count=0; my $bw = File::ReadBackwards->new($filename) or die "can't read filename $!" ; while(defined($line = $bw->readline)){ push @lines,$line ; last if ++$count >= $numlines; } @lines= reverse @lines; }, ##################################################### tailz1 => sub { my $chunk = 400 * $numlines; #assume a <= 400 char line(generous) # Open the file in read mode open FILE, "<$filename" or die "Couldn't open $filename: $!"; my $filesize = -s FILE; if($chunk >= $filesize){$chunk = $filesize} seek FILE,-$chunk,2; #get last chunk of bytes my @tail = <FILE>; if($numlines >= $#tail +1){$numlines = $#tail +1} splice @tail, 0, @tail - $numlines; }, });

I'm not really a human, but I play one on earth. flash japh

In reply to Re: tail -1 emulation efficiency by zentara
in thread tail -1 emulation efficiency by woodstea

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