the sysread problem can be corrected with a fairly simple change - just check for the last buffer for the end of line. sample program showing some of the variations:

#
# demonstrate the sysread (and read) problem and correction.  we reall
+y only need a small
# file to demonstrate the problem....
#

use strict;

my $test_file="sysread_test_file.txt";       # change name to test siz
+e/length differences

#
# create the test file
#
sub create_test_file
{
    return if -e $test_file;               # we do not want to create 
+if it already exists....
    open TOUT,">$test_file";
    #
    # write a small file with an extra line missing the EOL.
    #
    for (my $line=0;$line<1000;$line++)
    {
        print TOUT "qwertyuiopasdfghjklzxcvbnm1234567890qwertyuiopasdf
+ghjklzxcvbnm1234567890qwertyuiopasdfghjklzxcvbnm1234567890\n";
    }
    print TOUT "qwertyuiopasdfghjklzxcvbnm1234567890qwertyuiopasdfghjk
+lzxcvbnm1234567890qwertyuiopasdfghjklzxcvbnm1234567890";      # no EO
+L!
    close TOUT;
}

sub test_while_variable
{
    my $linecount=0;
    open TIN,"<$test_file";
    while (<TIN>)
    {
        $linecount++;
    }
    close TIN;
    print "test_while_variable: $linecount\n";
}

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

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

sub test_block_sysread($)
{
    my $block_size=$_[0];
    open TIN,"<$test_file";
    my ($data, $n);
    my $newlinecount=0;
    while ((sysread TIN, $data, $_[0]) != 0)
    {
        $newlinecount+=($data =~ tr/\012//);
    }
    close(TIN);
    print "test_block_sysread: $newlinecount\n";
}

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

#
# do the test
#

create_test_file;         # create the test file if not already presen
+t
test_while_variable;
test_block_read 4096;
test_fixed_block_read 4096;
test_block_sysread 4096;
test_fixed_block_sysread 4096;
exit 0;
[download]

---

---

Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!

Titles consisting of a single word are discouraged, and in most cases are disallowed outright.

Read Where should I post X? if you're not absolutely sure you're posting in the right place.

Please read these before you post! —

• How do I compose an effective node title?
• How do I post a question effectively?
• Markup in the Monastery

Posts may use any of the Perl Monks Approved HTML tags:

a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr

You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)

	For:		Use:
	&		&
	<		&lt;
	>		&gt;
	[		&#91;
	]		&#93;

Link using PerlMonks shortcuts! What shortcuts can I use for linking?

See Writeup Formatting Tips and other pages linked from there for more info.