#! perl

use strict ;
use warnings ;
$|++ ;

my %myhash = () ;
while ( <DATA> )
{
    my ( $key, $value ) = split ;
    push( @{ $myhash{ $key } }, $value ) ;
}

for my $key ( qw/ ni perch shrubbery / )
{
    if ( $myhash{ $key } )
    {
        print "Found $key on pass 1.\n" ;
    }
}

for my $key (  qw/ ni perch shrubbery / )
{
    if ( $myhash{ $key } )
    {
        print "Found $key on pass 2.\n" ;
    }
}

__DATA__
foo 1
bar 2
zoot 3
perl 4