use strict;
use warnings;

print <<BLOCK1;
1    2    -    perlmonks1    sdweq23
3    4    -    javaforums2    sd341
5    6    -    deamtech3    fr4frf34
7    8    +    dreamtech3    dcvdf3443
9    10    +    sunforum4    sdcds3443
11    12    -    sunforum4    ddfvdv333

BLOCK1

print <<BLOCK2;
1    2    -    perlmonks1    sdweq23    one
3    4    -    javaforums2    sd341    one
5    6    -    deamtech3    fr4frf34    start
7    8    +    dreamtech3    dcvdf3443    end
9    10    +    sunforum4    sdcds3443    start
11    12    -    sunforum4    ddfvdv333    end
BLOCK2
[download]

or was there more you wanted to tell us about your problem?

Lol :)
Good reply grandfather :)
However, I think i means he wants to find out some kind of session end/beginning for the users
Well that's an "assumption" only :)
TIMTOWTDI

Put in a hash or AoA, check for duplicity, flag it.
Print out the hash/aoa
[download]

Raghu

I want to find out the smallest and largest value in field 1 and then print it as start / end and if there is only 1 key value pair then print it as one.

Not sure what you consider to be the key/value pair

This code should get you started.

use strict;
use warnings;

my @list = split /\n/, <<BLOCK1;
1    2    -    perlmonks1    sdweq23
3    4    -    javaforums2    sd341
5    6    -    dreamtech3    fr4frf34
6.5  6.6    -    dreamtech3    fr4frf34
7    8    +    dreamtech3    dcvdf3443
9    10    +    sunforum4    sdcds3443
11    12    -    sunforum4    ddfvdv333

BLOCK1

my ($oldname1,$oldname2) =("") x 2;
my ($buf, $occurrances)=(0,0);
my ($max,$min);

for (@list,""){
  my ($num1,$num2,$sign,$name1, $name2) = split;
  if ($name1 && $name1 eq $oldname1){
      $occurrances++ ==1 and $buf .= " start";
  }else{
      if ($occurrances > 1){
           $buf .= " end";
      }elsif ($occurrances ==1){
           $buf .= " one";
      }
      $occurrances = 1;
  }
  (! defined $max) || ($num1 &&  $num1 > $max )  and $max = $num1;
  (! defined $min) || ($num1 &&  $num1 < $min)  and $min=$num1 ;
  print "$buf\n" if $buf;      
  $buf = $_;
  $oldname1=$name1;
}

print "Min=$min;  Max=$max\n";
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     Potentia vobiscum ! (Si hoc legere scis nimium eruditionis habes)

#!/usr/bin/perl

use strict;

my $data_pos = tell DATA;
my %record_of;

while (my $line = <DATA>) {
    chomp( $line );
    my ($key, $val) = (split /\s+/, $line)[3,4];
    $record_of{$key}++;
}

seek DATA, $data_pos, 0;

while (my $line = <DATA>) {
    chomp( $line );
    my ($key, $val) = (split /\s+/, $line)[3,4];

    print "$line  one\n" if ( $record_of{$key} == 1 );
    print "$line  end\n" if ( $record_of{$key} == 0 );

    if ( $record_of{$key} == 2 ) {
        $record_of{$key} = 0;
        print "$line start\n";
        next;
    }
}

__DATA__
1    2    -    perlmonks1    sdweq23
3    4    -    javaforums2    sd341
5    6    -    dreamtech3    fr4frf34
7    8    +    dreamtech3    dcvdf3443
9    10    +    sunforum4    sdcds3443
11    12    -    sunforum4    ddfvdv333
[download]