I think your best bet is to give GrandFather enough information to do something clever, elegant, and efficient. Pending that, here's my contributuion to getting the last line from each of the three files in a fairly basic way. 
my $last_line;
for my $fname ( 'tax.pl', 'accno.pl', 'ptax.pl' ) {
  open INFILE, $fname;
  while (<INFILE>) {
    chomp;
    $last_line = $_;
  }
  close INFILE;
  print "$fname:$last_line\n";
  $last_line = '';   # in case 2nd or 3rd file is empty
}

[download]
This will work with huge files, where you don't want to store the whole file in memory, although, by the extensions, I'm guessing your files are fairly short. Also, for huge files, you almost certainly want File::ReadBackwards as davorg has already suggested.

In reply to Re: how can i read only the last line of a files by rodion
in thread how can i read only the last line of a files by Anonymous Monk

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post, it's "PerlMonks-approved HTML":


  • 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! —
  • 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:
    & &amp;
    < &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.