#!/usr/bin/perl

# our needed packages
use strict "vars";
use Getopt::Std;

# Global Variables
my $VERBOSE = 0;
my $DEBUG = 0;

my $OUTPUT;

# commandline options

my $opt_string = "vdhc:i:o";
getopts( "$opt_string", \my %opt ) or usage() and exit(1);

$VERBOSE = 1 if $opt{'v'};
$DEBUG = 1 if $opt{'d'};
$OUTPUT = 1 if $opt{'o'};

if ( $opt{'h'} ) {
    usage();
    exit 0;
}

my $COMMAND = $opt{'c'};
my $INTERVAL = $opt{'i'};

( usage() and die "You have to specify a command!! \n") unless $COMMAND;

if ( not $INTERVAL )
{ 
    $INTERVAL = 3;
}
my $USER = qx("whoami");
chomp $USER;


####################################################
# Main part

my $PID;

my $PSTATUS;
my $MINORPF;
my $MAJORPF;
my $CPUTIME;
my $THREADS;

my $VMSIZE;


system("$COMMAND&");

open(PSAUX,"ps aux |") or die  "Error creating PSAUX file  $!\n";
  
    while ( my $targetline = <PSAUX> ) {
	        if ($targetline =~ /^$USER\s+(\d+)\s.*\d:\d\d\s$COMMAND$/) {
		   # print "PS AUX RELATED LINE IS: $targetline\n ";
		    $PID = $1;
		    print "\n";
		    print "Process ID is: $PID , Refresh Interval is: $INTERVAL \n";
		    print "-------------------------------------------------------------------------\n"
          }
    }

close (PSAUX);

if ($OUTPUT) {
    open (OUTFILE, ">$PID") or die "Error creating OUTPUT file $!\n";
    print "Writing the results to the file $PID Please wait...\n";
}
  

while (stat ("/proc/$PID") ) {
    my $TIME = time;	
    if ($PID) {
	open(STAT, "/proc/$PID/stat") or die  "Error creating STAT file  $!\n";
	my $line = <STAT>; 
	close(STAT); 
	my @statarray = split /\s+/,$line;
	
	# print @statarray[1];
	$PSTATUS = @statarray[2];
	$MINORPF = @statarray[9];
	$MAJORPF = @statarray[11];
	$CPUTIME = @statarray[15];
	$THREADS = @statarray[19];

	
	open(STATUS,"/proc/$PID/status") or die  "Error creating STATUS file  $!\n";
	
	while ( my $targetline = <STATUS> ) {
	    if ($targetline =~ /^VmSize:\s+(\d+)\s+kB $/) {
		$VMSIZE = $1;
	    }
	}
	
	close (STATUS);
	
    

if ($OUTPUT) {
    print OUTFILE "TIMESTAMP:$TIME,PSTATUS:$PSTATUS,MINORPF:$MINORPF,MAJORPF:$MAJORPF,CPUTIME:$CPUTIME,TREADS:$THREADS \n\n";    
}
    else {
      print "TIMESTAMP:$TIME,PSTATUS:$PSTATUS,MINORPF:$MINORPF,MAJORPF:$MAJORPF,CPUTIME:$CPUTIME,TREADS:$THREADS \n\n";
    }

    sleep $INTERVAL;
    }
}

close(OUTFILE);

# system ("kill -9 $PID");
exit 0;


#####################################################
# subroutines


sub usage {
    
    print "Usage:\n";
    print "-h for help\n";
    print "-v for verbose (more output ) \n";
    print "-d for debug (even more output)\n";
    print "-c <command> The linux command to run and track it \n";
    print "-i <Time Interval> Time Interval for tracking \n";
}


sub verbose {
    print "VERBOSE: " . $_[0] if ( $VERBOSE or $DEBUG );
}


sub debug {
    print "DEBUG: " . $_[0] if ( $DEBUG );
}