Host_Alias HA_FOO_GROUP = abc123, eigh456, \
                          foo987, bar654
#comment line
Runas_Alias RA_FOO_SVCACCT = www-data, ceph, \
                             sshd, memcache, \
                             xab123



#comment line
User_Alias CA_FOO_CSVACCT = www-foo, ceph, \
                             sshd, memcache, \
                             xab456

##</code><code>##

C:\monks>perl parse.pl input.txt
Alias type : Host_Alias
Alias name : HA_FOO_GROUP
Values     : abc123 eigh456 foo987 bar654
 ****
Alias type : Runas_Alias
Alias name : RA_FOO_SVCACCT
Values     : www-data ceph sshd memcache xab123
 ****
Alias type : User_Alias
Alias name : CA_FOO_CSVACCT
Values     : www-foo ceph sshd memcache xab456
 ****

C:\monks>

##</code><code>##

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

die "Error. Usage \'perl parse.pl inputfile.txt\'\n $!" unless $#ARGV == 0;

my $in_filename  = shift @ARGV;

my $complete_line = "";

open(my $IN,"<",$in_filename)    || die "Cannot find input '$in_filename'\n $!";
	while(<$IN>)
	{
		chomp;
		next if ($_ eq "");
		next if (m/^\#/);

		if ($_ =~ m/\\$/)
		{
			$_ =~ s/\\$//;
			$complete_line .= $_;
			next
		}

		$complete_line .= $_;

		# get alias type and name
	
			my $index_pos = index($complete_line,'=');
			my @alias_type_and_name =  split(/ /, substr($complete_line,0,$index_pos-1) );
			
		# get alias values

			my @alias_values = split(/\,/, substr($complete_line,$index_pos+1) );

			foreach my $v (@alias_values)
			{
				$v =~ s/^\s+//;
				$v =~ s/\s+$//;
			}

		# print values

			print "Alias type : $alias_type_and_name[0]\n";
			print "Alias name : $alias_type_and_name[1]\n";
			print "Values     : @alias_values\n ****\n";

		$complete_line = "";
	}
close($IN);