#!/usr/bin/perl -w

use strict;
use IO::File;


print "Testing...\n";

my $t1 = '1';
my $t2 = '2';
my $t3 = '3';


my $fh = IO::File->new_tmpfile() or die $!;
$fh->format_name("TEST");

select($fh);
write();
seek($fh, 0, 0); # Rewind the file
my $str = do {local $/; <$fh>};

select(STDOUT);
print $str;


format TEST=
@||| @||| @|||
$t1,$t2,$t3
@||| @||| @|||
$t3,$t2,$t1
.

__END__
Output:

Testing...
 1    2    3
 3    2    1