#!/usr/bin/perl  -w

use strict;

my $process_id ; 
my @processes ;
my $index; 

##################################################
# Was this program called with an arguement
# Arguements can be a process id or program name
##################################################
if ( (@ARGV == "1") && ($ARGV[0]) =~ m/^\d+$/ )
{
  #
  # we received a process id.  
  #
  chomp ( $process_id=$ARGV[0] );
  print "Analyzing PID: $process_id\n";
} elsif ( (@ARGV == "1" ) && ($ARGV[0] =~ m/^\w.*$/) )
{
  print "received program name\n";
  #
  # find process id
  #
  chomp $ARGV[0];
  print "Checking for $ARGV[0]\n";
  open( PROCESSES, "pidof $ARGV[0] |" ) || die "No proces found: $!\n";
  @processes=split(" ",<PROCESSES>);
  #
  # Check if more than one process matches
  #
  if ( scalar (@processes) > 1 )
  {
    print "Matches processes: @processes\n";
    print "Which process is the one to watch?\t";
    #
    # Check if they entered one process ID
    #
    if ( scalar ( split(" ",<PROCESSES>) ) > 1 )
    {
      print scalar (<STDIN>);
      print "You aren't getting it.\n**ONE process can be watched**\nExiting\n";      
      exit;
    } else {
      chomp ( $process_id=<STDIN> );
      print "Analyzing PID: $process_id\n";
    }
  } else {
     chomp ( $process_id=$processes[0] );
     print "Analyzing PID: $process_id\n";
  }
}
else 
{
   print "usage: smaps_top.pl [PID|program]\n";
   exit;
}
##################################################
# Check for process
##################################################
if ( -e "/proc/$process_id" )
{
  print "Found: /proc/$process_id\n";
} else {
  print "Not Found: /proc/$process_id\n";
  exit;
}



my %mem_location={};
my $mem_address;
while ( 1 )
{
  ##################################################
  # parse each entery
  # load into hash of hashs
  ##################################################
  # Example
  # %mem_location = {
  #    "bfb52000-bfb55000 rw-p bfb52000 00:00 0" => {
  #	   Size 	 => "12B",
  #	   Rss  	 => "4",
  #	   Shared_Clean  => "0",
  #	   Shared_Dirty  => "0",
  #	   Private_Clean => "0",
  #	   Private_Dirty => "4",
  #	   Referenced	 => "4"
  #	}
  # }
  # Dereference:
  # $mem_location->"bfb52000-bfb55000 rw-p bfb52000 00:00 0" -> Size;
  #


  open ( SMAPS, "cat /proc/$process_id/smaps |" )|| die;
  while (<SMAPS>){
    if ( /^([a-f]|\d+)/ ... /^Referenced.*/){
      #if ( /^([a-z]|\d)?.*/)
      #{
      #   chomp ($mem_address="$_");
      #   print "$mem_address\n";
      # }
      if( /^([a-f]|\d+)/ ){
  	chomp ( $index="$_" );
      }
      elsif ( /^Size:\W+(\d+)\W+kB/ )
      {
  	 $mem_location{$index}{Size}="$1";
      }
      elsif ( /^Rss:\W+(\d+)\W+kB/ )
      {
  	 $mem_location{$index}{Rss}="$1";
      }
      elsif ( /^Shared_Clean:\W+(\d+)\W+kB/ )
      {
  	 $mem_location{$index}{Shared_Clean}="$1";
      }
      elsif ( /^Shared_Dirty:\W+(\d+)\W+kB/ )
      {
  	 $mem_location{$index}{Shared_Dirty}="$1";
      }
      elsif ( /^Private_Clean:\W+(\d+)\W+kB/ )
      {
  	 $mem_location{$index}{Private_Clean}="$1";
      }
      elsif ( /^Private_Dirty:\W+(\d+)\W+kB/ )
      {
  	 $mem_location{$index}{Private_Dirty}="$1";

      }
      elsif ( /^Referenced:\W+(\d+)\W+kB/ )
      {
  	 $mem_location{$index}{Referenced}="$1";
      }
    }
    #print "$index\t$mem_location{$index}{Size}\t$mem_location{$index}{Rss}\t$mem_location{$index}{Shared_Clean}\t$mem_location{$index}{Shared_Dirty}\t$mem_location{$index}{Private_Clean}\t$mem_location{$index}{Private_Dirty}\t$mem_location{$index}{Referenced}\n";
  }
  close(SMAPS) || die;

  print "Memory_Segment    Perm    Size   Rss  Shar_C Share_D Priv_C  Priv_D Referenced\n";

  foreach my $key (sort hashValueAscendingNum ( keys %mem_location) )
  {
      printf "%.22s %7d %5d %7d %7d %6d %7d %7d\n",
  	      $key,
  	      $mem_location{$key}{Size},
  	      $mem_location{$index}{Rss},
  	      $mem_location{$key}{Shared_Clean},
  	      $mem_location{$index}{Shared_Dirty},
  	      $mem_location{$key}{Private_Clean},
  	      $mem_location{$key}{Private_Dirty},
  	      $mem_location{$key}{Referenced};
  }
  
  sleep 1; 
  print " " x 80*25;  # clear screen
}

sub hashValueAscendingNum {
   $mem_location{$b}{Size} <=> $mem_location{$a}{Size};
}