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

my $output = '';

LINE: while ( my $line = <DATA>)  {

	chomp $line;

	# if line ended with a '\', remove '\' and save line for later output
	if ( $line =~ s/\\$// ) {
		# clean indentation
		$line =~ s/^\s+/ /;
		# save line
		$output .= $line;
		next LINE;
	}
	# we have previous line(s) to consider?
	elsif ( length $output ) {
		# clean indentation
		$line =~ s/^\s+/ /;

		$line = $output . $line;
		$output = '';
	}

	print $line, $/;
}


__DATA__
{FILE}
sourcetag1
{NUMBER}
00000
11111
{SOURCE}
source1
{KEYWORD}
{AUTHOR}
author1 staff1
{HEADLINE}
DISPOSABLE DECOR: THE CUTTING EDGE DULLS FAST\
			   STYLE AT A SPEED USUALLY ASSOCIATED WITH WARDROBE ITEMS.
{FILE}
sourcetag2
{NUMBER}
00002
{SOURCE}
sourcenam2
{KEYWORD}
{AUTHOR}
author2 staff2
a\
	b\
	c