#!/usr/bin/perl

use strict;
use warnings;

my %file1;
my $key;
my $value;


#usage() unless @ARGV == 0;
my $inf1="file2";
open (IN1, "$inf1");



my $output_file = pop @ARGV;

# read first file
while (<IN1>)
{
    chomp;
    ($key,$value) = split /:/, $_, 2
      or warn "Bad data on line $. in file $ARGV, ";
    $file1{$key} = $value 
      or warn "Bad data on line $. in file $ARGV, ";
}
continue
{
    # reset line numbers for warning messages
    # end loop
    if ( eof ) # note special form of eof
    {
        close IN1;
        last;
    }
}
my $inf2="file3";
open (IN2, "$inf2");
my $outf1=">endfile";
open (OUT1,"$outf1");


# read second file
while (<IN2>)
{
    chomp;
    ($key,$value) = split /:/, $_, 2
      or warn "Bad data on line $. in file $ARGV, ";
    if ( exists( $file1{$key} ) )
    {
        $file1{$key} .= ''. $value
          or warn "Bad data on line $. in file $ARGV, ";
    }
    else
    {
        warn "Can\'t find key matching <$key> (line $.) " 
          . "in file <$ARGV>, ";
        $file1{$key} = $value
          or warn "Bad data on line $. in file $ARGV, ";
    }
}        
continue
{
    last if ( eof ) # note special form of eof
}

#open( OUT, ">", $output_file )
  #or die "Error opening $output_file for writing, ";
  
foreach my $k ( sort keys %file1 )
{
    print OUT1 "$k:$file1{$k}\n";
}
close (OUT1);