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Perl plugin for Eclipse: 

Get it from here        http://e-p-i-c.sourceforge.net

Removing a file which is more that x days old: 

foreach (glob("*")) {
       $temp=$_;

       if (( -d $temp) and ($temp =~ m/[0-9]{6}\.(.*)/))
     {
       $age = -M ;
       if ($age > 7) {
               print "Removing the file  $temp as it more than 7 days old\n";
               system("rm -rf $temp");
       } else {
               print "Keeping the file $temp as it is just",int($age)," days old\n";
       }
     }
}
Perl to get HTTP authentication: 

  use LWP::UserAgent;
  $ua = LWP::UserAgent->new;
  $ua->credentials('site:80', 'realm', username' => 'password'); //site is just machine name eg.hostA.domain.com
  my $req = HTTP::Request->new(GET => 'http://test_Authntication/url/html'); //pass the comple URL here
  $ua->request($req);   print  $ua->content;

Perl to get all the contents of a file into a string:

open(HND,"<file_to_open.txt") or die "$1 can't be opened";
$whole_string=do{ local $/; <HND> };

close HND;

Perl to automate FTP :

 open(SHELL,">get_remote_file.sh");
print SHELL "#!/bin/csh\n";
print SHELL "ftp -i -n \<\< END_FTP\n";
print SHELL "open host-a.domain.com\n";
print SHELL "user user password\n";
print SHELL "cd \/tmp\n";
print SHELL "lcd  \/tmp\n";
print SHELL "mget \*\.zip\n";
print SHELL "bye\n";
print SHELL "END_FTP\n";
close SHELL;
chmod 0777,"get_remote_file.sh";
system("\.\/get_remote_file.sh > get_remote_file.log"); 

Perl to covert IP address -> hostname and  vice-versa:
=====================================
Usage: perl  filename.pl   <IP address or a hostname>
=====================================
use Socket;
use strict;
my $host_name = hostname($ARGV[0]);
print "$ARGV[0] resolves to $host_name\n";
sub hostname
{
  my (@bytes, @octets,$packedaddr,$raw_addr,$host_name,$ip);
  if($_[0] =~ /[a-zA-Z]/g)
    {
     $raw_addr = (gethostbyname($_[0]))[4];
     @octets = unpack("C4", $raw_addr);
     $host_name = join(".", @octets);
   }
  else
    {
     @bytes = split(/\./, $_[0]);
     $packedaddr = pack("C4",@bytes);
     $host_name = (gethostbyaddr($packedaddr, 2))[0];
    }
 return($host_name);
} 

Perl to do simple HTTP post:

use HTTP::Request::Common qw(POST);
use LWP::UserAgent;
$ua = LWP::UserAgent->new;
my $req = POST 'http://localhost:80/hello.jsp',[ newName => 'xyz', errors => 0 ];
print $ua->request($req)->as_string;
 

Client/Server Socket programming in Perl:

server.pl: 

 use strict;
 use Socket;
 # use port 7890 as default
 my $port = shift || 7890;
 my $proto = getprotobyname('tcp');
 # create a socket, make it reusable
 socket(SERVER, PF_INET, SOCK_STREAM, $proto) or die "socket: $!";
 setsockopt(SERVER, SOL_SOCKET, SO_REUSEADDR, 1) or die "setsock: $!";
 # grab a port on this machine
 my $paddr = sockaddr_in($port, INADDR_ANY);
 # bind to a port, then listen
 bind(SERVER, $paddr) or die "bind: $!";
 listen(SERVER, SOMAXCONN) or die "listen: $!";
 print "SERVER started on port $port ";
 # accepting a connection
 my $client_addr;
 while ($client_addr = accept(CLIENT, SERVER))
 {
 # find out who connected
 my ($client_port, $client_ip) = sockaddr_in($client_addr);
 my $client_ipnum = inet_ntoa($client_ip);
 my $client_host = gethostbyaddr($client_ip, AF_INET);
 # print who has connected
 print "got a connection from: $client_host","[$client_ipnum] ";
 # send them a message, close connection
 print CLIENT "Smile from the server";
 close CLIENT;
 } 

client.pl:

#----------------
use strict;
use Socket;
# initialize host and port
my $host = shift || 'server-host.us.oracle.com';
my $port = shift || 7890;
my $proto = getprotobyname('tcp');
# get the port address
my $iaddr = inet_aton($host);
my $paddr = sockaddr_in($port, $iaddr);
#create the socket, connect to the port
socket(SOCKET, PF_INET, SOCK_STREAM, $proto) or die "socket: $!
connect(SOCKET, $paddr) or die "connect: $!";
my $line;
while ($line=<SOCKET>)
{
print $line;
}
close SOCKET or die "close:$!"; 

 Perform the following steps:-

 Now ,start the server in ur server machine where you have written server.pl

server-host> perl server.pl

Now u can run client.pl from any machine  in ur network,

client-host>perl  client.pl

 Smile from the server

Recursive search for a particular file , given a top level directory:

 #!/bin/perl
 use File::Find;
 @ARGV = ('C:/topleveldir') unless @ARGV;
 find(\&callup,@ARGV );
sub callup {

  if($_ =~ /^I_m_looking_for_this_file.txt$/)
  {
        print  $File::Find::name;
  }
}

In Place file modification:

This module makes a file look like a Perl array, each array element corresponds to a line of the file

 #!/usr/bin/perl
 
use Tie::File;
 
#-- modify all ocurrences of 'HowTo' to 'how to'
tie @lines, 'Tie::File', "readme.txt" or die "Can't read file: $!\n";
foreach ( @lines )
{
  s/HowTo/how to/g;
}
untie @lines;

Converting Perl programs to exe 's:

http://www.indigostar.com/perl2exe.htm tool can serve the purpose. Exe's can be built from Perl programs and run across anywhere, without having perl interpreter