getting the difference in the number lines

[Natalie30]

I need help seeing the difference in the number lines, in this script i writing back the previous number of lines. I need a subtraction statement. thanks, N


$data_file = "/root/bin/load.data2";
open(FILE,&quot;<$data_file&quot or die &quot;Cant open $data_file2: $!\n&quot;;
@log = <FILE>;
$last_element='&quot;0&quot;';
foreach(@log){
chomp;
s/\015//;
my@list = split',';
print&quot;$_,$last_element\n&quot;;
$last_element = $list[$#list];
}
close (FILE);


<output>
&quot;Mon Feb 10 11:28:00 2003&quot;,&quot;17.42&quot;,&quot;134&quot;,&quot;1443&quot;,&quot;69978&quot;,&quot;69041&quot;
&quot;Mon Feb 10 11:29:00 2003&quot;,&quot;19.98&quot;,&quot;118&quot;,&quot;1288&quot;,&quot;70729&quot;,&quot;69978&quot;
&quot;Mon Feb 10 11:30:00 2003&quot;,&quot;20.26&quot;,&quot;195&quot;,&quot;1328&quot;,&quot;71443&quot;,&quot;70729&quot;

 

[svar]

Natalie30,
do you really want your script to give you

&quot;Mon Feb 10 11:28:00 2003&quot;,&quot;17.42&quot;,&quot;134&quot;,&quot;1443&quot;,&quot;69978&quot;,&quot;69041&quot;, &quot;937&quot;(the difference between 69978 and 69041) and so on?
Perhaps it will be clearer if you list a small
portion of the input file and be a bit clearer in what you
want the scipt to do

svar