高分求救：如何实现搜索目录查找需要的文件。

[GC80]

以下是我的程序：有问题
就是不能完全实现搜索。
有没有什么好的方法可用？或帮我把下面的bug搞定也不甚感激。

#!/usr/bin/perl -w

use strict;

my $directory = "/tmp/";

OpenSub("$directory");

#recursion open the sub directory
sub OpenSub{

my($dir);
my($file);

my(@lines);
my(@replacelines);

$dir = $_[0];
print "\nCall Opensub($dir)\n";

opendir(DH, $dir) || die "Cannot open $dir: $!";

while ($file = readdir DH){ #read the file name one line
print "\n$dir/$file\n";

if (-f "$dir/$file")
{
print " $file is a File!!\n";
$_ = $file;

if (/.txt$/){
print "$dir/$file is a txt file\n";
if ( open(F, "$dir/$file") ){
@lines = <F>;
print @lines;
close(F);
}
}
else
{
print "$dir/$file is not a txt file\n";
}
}
else
{
$_ = $file;
if (/^\.\.?$/){
print "$dir/$file is a NOT Really Directory!!\n";
}
else
{
print "$dir/$file is a Really Directory!!\n";
OpenSub("$dir/$file");
}

}

}
closedir(DH);
}