use strict;
use warnings;

my $IP_file = << 'END';
1.0.129.197
1.0.131.49
1.0.131.74
1.0.138.143
1.0.138.154
1.0.139.72
END

my $Port_file = << 'END';
3		PORT	state	protocol
3		80/tcp   closed http
3		443/tcp  closed https
3		8080/tcp open   http-proxy
5		80/tcp   open     http
5		443/tcp  filtered https
5		8080/tcp filtered http-proxy
END

my $output_file;

open my $IP,   "<", \$IP_file      or die "unable to open IP file for reading $!"; 
open my $PORT, "<", \$Port_file    or die "unable to open port file for reading $!"; 
open my $OUT,  ">", \$output_file  or die "unable to open output file for writing $!";

<$PORT>;  # throw away first line ion port file

while (defined (my $ip_line =<$IP>) and defined (my $port_line = <$PORT>))
{
   chomp $ip_line;
   $port_line =~ s/^\d+\s+/$ip_line /;
   print "$port_line";
}

__END__
Prints:
1.0.129.197 80/tcp   closed http
1.0.131.49 443/tcp  closed https
1.0.131.74 8080/tcp open   http-proxy
1.0.138.143 80/tcp   open     http
1.0.138.154 443/tcp  filtered https
1.0.139.72 8080/tcp filtered http-proxy