readdir is not my friend. If you use File::Find, you don't have to mess with relative vs. absolute pathnames. You can use $File::Find::name, which is a complete pathname. You don't have to worry about '..' and '.'. Etc. etc. Quite untested:

use File::Find;

find(\&wanted, '/temp_gif');

sub wanted {
   return unless /^\d+\.gif$/i;

   (my $new_name = $File::Find::name) 
      =~ s/(\d+)\.gif$/($1+398) . 'GIF'/ei;  

   rename($File::Find::name, $new_name) or die $!;
}

[download]

In reply to Re: rename files by chester
in thread rename 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.