root@swill ~/PerlMonks
$ cat mergefile.1
15      20      foo
22      30      bar
30      33      baz
14      22      fubar

root@swill ~/PerlMonks
$ cat mergefile.2
alpha   baz     17.30
gamma   foobar  22.35
gamma   bar     19.01
delta   fromish 33.03
sigma   bear    14.56

root@swill ~/PerlMonks
$ ./file_merge.pl

root@swill ~/PerlMonks
$ cat mergefile.out
bar     22      30      gamma   19.01
baz     30      33      alpha   17.30
bear    null    null    sigma   14.56
foo     15      20      null    null
foobar  null    null    gamma   22.35
fromish null    null    delta   33.03
fubar   14      22      null    null

root@swill ~/PerlMonks
$