I had my bad time copying your code and reformatting it. Please check the Writeup Formatting Tips and fix your layout to be at least readable.

Your code seems to works fine, readdir returns correct data (neither null?? or undef) and push all the files which ends with '.lip' in the @names array.

Oha

Ps: for other monks, i've put the OP code below 

opendir( DIR, $directory ) or die "open dir error";
my $number = 0;
while(defined($name = readdir (DIR)))
{
        $number++;
        if($name eq "")
        {
                print "Value -$name* is null string."
        }
        print "Loop $number-->$name**\n";
        next if $name eq "." || $name eq "..";
        next unless $name =~ /(.*)\.lip$/;
        push @names, $name;
}

[download]

In reply to Re: readdir return nul string by oha
in thread readdir return nul string by marscld

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.