XenServer 6.x script to set VM auto poweron

xenserver_poweron.pl

#!/usr/bin/perl
use strict;
use Term::ANSIColor;

&print_usage && exit if $ARGV[0] =~ /^-{1,2}h(elp)?/;

if ($ARGV[0]) {

	&print_usage && die "error: poweron must be true or false\n" if $ARGV[1] !~ /^(false|true)$/;
	
	my ($name, $poweron) = @ARGV;
	my $uuid = `xe vm-list name-label=\"$name\" | grep uuid`;
	if ($uuid =~ s/.*: ([\w-]+)\n$/$1/) {
		my $return = `xe vm-param-set uuid=$uuid other-config:auto_poweron=$poweron`;
		print $return;
	} else {
		&print_usage && die "error: failed to get VM uuid\n";
	}
	
} else {

	my @uuid = `xe vm-list | grep uuid`;
	@uuid = map {s/.*: ([\w-]+)\n$/$1/; $_} @uuid;

	for (@uuid) {
		my $name = `xe vm-param-get uuid=$_ param-name=name-label`; 
		my $param = `xe vm-param-get uuid=$_ param-name=other-config`;
		
		print "Server: $name";
		if ($param =~ /auto_poweron: true/) {
			print 'auto_poweron: ', color('green'), "true\n\n";
		} else {
			print 'auto_poweron: ', color('red'), "false\n\n";
		}
		print color 'reset';
		
	}

}

sub print_usage {
	warn "\nUSAGE:\n============\n";
	warn "List poweron setting for all VMs:\n\$ $0 \n\n"; 
	warn "Set VM to power on during boot:\n\$ $0 <vmname> <true|false>\n\n";
	warn "Don't forget to configure your XenServer pool to auto start VMs: http://support.citrix.com/article/CTX133910\n\n";
}

at line 12 You can simply get the uuid of the vm without the extra grep, and processing of the output with:
xe vm-list params=uuid name-label=\"$name\" is-control-domain=false --minimal

at line 22 To filter out the xenserver host itself, and to get the uuid-s in one step you could use following command:
xe vm-list params=uuid is-control-domain=false --minimal
this would present you a comma-delimited listing of the uuid-s which would be lot more easy to map the list.