#!/usr/local/bin/perl
$self = $0;
$self =~ s!^.*/!!;
#
$[ = 1; # = number of first index into arrays and strings
#
$FIELD_SEPARATOR = '\t';
$FIELD_NUMBER_LIST =('38','82');
$field_separator = $FIELD_SEPARATOR;
$field_number_list = $FIELD_NUMBER_LIST;
#
while (@ARGV)
{
    $_ = shift;
    if    (/^-F$/)    { $field_separator = shift; }
    elsif (/^-L$/)    { $field_number_list = shift; }
    elsif (/^-F.+$/)  { $field_separator = substr($_,$[+2); }
    elsif (/^-L.+$/)  { $field_number_list = substr($_,$[+2); }
    #else              { push(@filename, $_); }
}
#
$file_a = 'file1';
$file_b = 'file2';
#
unless (($file_a ne "") && (-f $file_a))
{
    die "Error: Can't find file '$file_a'!\n";
}
unless (($file_b ne "") && (-f $file_b))
{
    die "Error: Can't find file '$file_b'!\n";
}
#
@index_list = split(/,/, $field_number_list);
#
# Scan first file, Pass 1:
open(FILE_A, "<$file_a") || die "Can't open '$file_a': $!\n";
#
while (<FILE_A>)
{
    chop if /\n$/;
    undef $key;
    undef @field;
    @field = split(/$field_separator/o);
    foreach $index (@index_list)
    {
        if (defined $key)
        {
            $key .= "\n" . $field[$index];
        }
        else
        {
            $key = $field[$index];
        }
    }
     $intersection{$key} = 1;
}
#
close(FILE_A);
# Scan second file, Pass 1:
#
$empty_intersection = 1;
#
open(FILE_B, "<$file_b") || die "Can't open '$file_b': $!\n";
#
while (<FILE_B>)
{
    chop if /\n$/;
    undef $key;
    undef @field;
    @field = split(/$field_separator/o);
    foreach $index (@index_list)
    {
        if (defined $key)
        {
            $key .= "\n" . $field[$index];
        }
        else
        {
            $key = $field[$index];
        }
    }
 $code = $intersection{$key};
if ($code == 1)
    {
        $intersection{$key} = 3;
        $empty_intersection = 0;
    }
    else
    {
        if ($code != 3) { $intersection{$key} = 2; }
    }
}
#
close(FILE_B);
#
# Prepare output file names:
$file_a_1 = $file_a . '.1';
#
# Scan first file, Pass 2:
#
open(FILE_A, "<$file_a")     || die "Can't open '$file_a': $!\n";
open(FILE_A_1, ">$file_a_1") || die "Can't write '$file_a_1': $!\n";
#
while (<FILE_A>)
{
    chop if /\n$/;
    undef $key;
    undef @field;
    @field = split(/$field_separator/o);
    foreach $index (@index_list)
    {
        if (defined $key)
        {
            $key .= "\n" . $field[$index];
        }
else
        {
            $key = $field[$index];
        }
    }
    if ($intersection{$key} == 3)
    {
       # 
    }
    else
    {
        print FILE_A_1 $_, "\n";
    }
}
#
close(FILE_A);
close(FILE_A_1);
#
# Scan second file, Pass 2:
#
open(FILE_B, "<$file_b")     || die "Can't open '$file_b': $!\n";
open(FILE_A_1, ">>$file_a_1") || die "Can't write '$file_a_1': $!\n";
#
while (<FILE_B>)
{
    chop if /\n$/;
    undef $key;
    undef @field;
    @field = split(/$field_separator/o);
    foreach $index (@index_list)
    {
        if (defined $key)
        {
            $key .= "\n" . $field[$index];
        }
        else
        {
            $key = $field[$index];
        }
    }
    if ($intersection{$key} == 3)
    {
      #      }
    else
    {
        print FILE_A_1 $_, "\n";
    }
}
#
close(FILE_B);
close(FILE_A_1);
#
# Display results:
#
printf("The Diff file created '%s'\n\n", $file_a_1);
#