#!/usr/bin/perl
use strict;
use warnings;

package Commands;
use vars qw(@ISA @EXPORT @EXPORT_OK %EXPORT_TAGS $VERSION);
use Exporter;
our $VERSION=1.0;
our @ISA = qw(Exporter);
our @EXPORT = qw(%cmd_tmpl eval_cmd);
our @EXPORT_OK = qw();

our sub eval_cmd ($);

####################################################################
####################################################################

## Command Hash template
our %cmd_tmpl = 
(
	'backup' => 'token token > token',
	'list'   => 'token -le token'
);

## Evaluate command , accepts Command , Client, and Arguments
our sub eval_cmd ($)
{
	my $array_ref = shift;
	
	my $cmd = @{$array_ref}[0];
	my $client = @{$array_ref}[1];	
	my @args;
	
	if ( defined @{$array_ref}[2] )	
	{
		@args = split(/ /,@{$array_ref}[2]);
	}

	die "No such command: $cmd!" unless exists $cmd_tmpl{lc($cmd)}; ## convert command to lc internally

	my $cmd_value = $cmd_tmpl{$cmd};
	
	## update command , replaces first 'token' encountered.
	$cmd_value =~ s/token/$cmd/;
	
	## update client , replaces first 'token' encountered.
	$cmd_value =~ s/token/$client/;
	
	## update arguments , replaces first 'token' encountered.
	for(my $i = 0; $i <=$#args; $i++)
	{	
		$cmd_value =~ s/token/$args[$i]/;
	}	
	
	if ($cmd_value =~ m/token/)
	{
		die "Not enough aruments on [@{$array_ref}]";
	}
	return $cmd_value;
}

####################################################################
####################################################################

1;

##</code><code>##

#/usr/bin/perl
use strict;
use warnings;

use Commands 1.0;

sub Get_Client();
my @clients;

die "Error. Usage \'perl Command_parser.pl -Noclient | [-Command Client1 Arguments  -Command Client2 Arguments...] \'\n $!" unless $#ARGV >= 0;

####################################################################
####################################################################

## If a client was not provided at the command line, get one
if (lc($ARGV[0]) eq "-noclient")
{
	Get_Client();
}
else
{
	my @current_command;
	
	for(my $i = 0; $i <=$#ARGV; $i++)
	{
		if ( $ARGV[$i] =~ m/^\-/ && $i != 0)
		{
			# eval current command , then wipe it and keep processing
			
			my $command_value = eval_cmd(\@current_command);			
			print "Command is :$command_value\n";
			
			##system($command_value);
			
			@current_command = ();
			push @current_command , $ARGV[$i];
			$current_command[0] =~ s/\-//g;
		}
		elsif ( $i == $#ARGV )
		{
			# eval last command
			
			push @current_command , $ARGV[$i];
			my $command_value = eval_cmd(\@current_command);
			print "Command is :$command_value\n";
			
			##system($command_value);
		}
		else
		{
			push @current_command , $ARGV[$i];
			if ($i == 0)
			{
				$current_command[0] =~ s/\-//g;
			}
		}	
	}
}

####################################################################
####################################################################

## No client was provided at the command line, fill one in
sub Get_Client()
{
	my @current_command = ('backup','mars','file1.txt');
		
	my $cmd_value = eval_cmd(\@current_command); # here magic happens!

	##security_check($cmd);
	##system("$cmd");
}


##</code><code>##


C:\monks\command_template>perl Command_parser.pl -backup client1 myfile1.txt -backup client2 myfile2.txt -list client3
Command is :backup client1 > myfile1.txt
Command is :backup client2 > myfile2.txt
Command is :list -le client3