correction to the "fixed" routines in the demonstration code - it did not handle the "good" EOL case correctly because the "tr" removed the EOL and the original code thought the (good) EOL was missing as a result (I guess I learn something every day). this fix may not be perfect - I think it will return 1 for an empty file (untested) but I am sure there is a fix for that if someone really wants to do it.

I will not be offended if someone finds yet another problem (besides the empty file problem) and comes up with a solution. that is what this site is for - to help people do a better job writing Perl code and to teach people little things about Perl that they may not have known or thought much about. 

sub test_fixed_block_read($)
{
    my $block_size=$_[0];
    open TIN,"<$test_file";
    binmode TIN;
    my ($data, $n);
    my $newlinecount=0;
    my $block_ends_with_eol=0;
    while ((read TIN, $data, $_[0]) != 0)
    {
        $block_ends_with_eol=1 if (substr $data,-1,1) eq "\n";
        $newlinecount+=($data =~ tr/\012//);
    }
    close(TIN);
    $newlinecount++ if (!$block_ends_with_eol);
    print ">>>test_fixed_block_read: $newlinecount\n";
}

sub test_fixed_block_sysread($)
{
    my $block_size=$_[0];
    open TIN,"<$test_file";
    my ($data, $n);
    my $newlinecount=0;
    my $block_ends_with_eol=0;
    while ((sysread TIN, $data, $_[0]) != 0)
    {
        $block_ends_with_eol=1 if (substr $data,-1,1) eq "\n";
        $newlinecount+=($data =~ tr/\012//);
    }
    close(TIN);
    $newlinecount++ if (!$block_ends_with_eol);
    print ">>>test_fixed_block_sysread: $newlinecount\n";
}

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In reply to Re^2: Count number of lines in a text file by Anonymous Monk
in thread Count number of lines in a text file by Scott7477

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