#!/bin/sh -- # A comment mentioning perl, indented for bash's sake.
eval 'exec perl -S $0 ${1+"$@"}'
        if 0;

chop($Program = `basename $0`);

$join = 0;
$trim = 0;

$Usage = <<"END";

$Program: XXX

Usage: $Program <options>

Options:

Notes:

END

LOOP:	
while (@ARGV) {
    $_ = shift;
    CASE: {
	/^-j$/ && ($join = 1, last CASE);
	/^(-t|-trim)$/ && ($trim = 1, last CASE);
	/^-d$/ && ($Debug = 1, last CASE);
	/^--$/ && (last LOOP);	# -- means end of switches
	/^-(-.*)$/ && (unshift(@ARGV, $1), last CASE);
	/^(-h|-help)$/ && ((print STDERR $Usage), exit 0, last CASE);
	if ( /^-(..+)$/ ) {	# split bundled switches:
		local($y, $x) = ($1, '');
		foreach $x (reverse(split(//, $y))) { unshift(@ARGV,"-$x") };
		last CASE;
	}
	/^-/ && ((print STDERR "Invalid arg: $_\n$Usage"), exit 1, last CASE);
	unshift(@ARGV,$_);
	last LOOP;
    }
}
$cnt = 0;
while(<>) {
	chop;
	push(@Line, $_);

	$beg = $_;
	$beg =~ s/\S.*$//;
	push(@Beg, length($beg) + 1);

	$end = $_;
	$end =~ s/\s*$//;
	push(@End, length($end) - 1);
}

$last_beg = -1;
$last_end = -1;
$| = 1;

for ($i=0; $i < @Line; $i++) {
	$this_beg  = $Beg[$i];
	$this_end  = $End[$i];
	$this_line = $Line[$i];
	if ( $this_line =~ /^\s*$/ ) {
		print "\n";
		next;
	}

	$overlap = 0;
	if ( $last_beg <= $this_beg  &&  $this_beg <= $last_end ) {
		$overlap = 1;
	}
	if ( $last_beg <= $this_end  &&  $this_end <= $last_end ) {
		$overlap = 1;
	}

	if ( $overlap || $this_beg < $last_beg ) {
		if ( $join && $overlap ) {
			$tmp = $Line[$i];
			$tmp =~ s/^\s*/ /;
			$tmp =~ s/^\s*// if $trim;
			print $tmp;
		} else {
			print "\n";
			$tmp = $Line[$i];
			$tmp =~ s/^\s*// if $trim;
			print $tmp;
		}
	} else {
		$tmp = substr($Line[$i], $last_end + 1);
		$tmp =~ s/^\s*// if $trim;
		print $tmp;
	}
	$last_beg = $this_beg;
	$last_end = $this_end;
}
print "\n";

exit 0;
sub trim {
	local($x) = @_;
	$x =~ s/^\s*//;
	$x =~ s/\s*$//;

	return $x;
}