nick 20/5/1950 one 
john 18/2/1980 two
nick 19/6/1978 three
nick 20/5/1950 four
nick 12/9/2000 five
john 15/6/1997 six
nick 20/5/1950 seven

##</code><code>##

nick 20/5/1950 one four seven
john 18/2/1980 two
nick 19/6/1978 three
nick 12/9/2000 five
john 15/6/1997 six

##</code><code>##

use strict;
use warnings;

my %res;
while (<>) 
{
    my ( $name, $rest ) = split /\t/;
    push @{ $res{$name} }, $rest;
}
for ( sort keys %res ) {
    print "$_ ", join( "|", @{ $res{$_} } ), "\n";
}