#! perl -slw
use strict;

my %fhs;
my $d = '|';
while(<>) {
    my ($first, $rest) = m[(^.*?)\Q${d}\E(.*$)];
    open $fhs{$first}, '>>', $first
        or die "Couldn't open $first:$!"
        unless $fhs{$first};

    print { $fhs{$first} } $rest;
}

##</code><code>##

#! perl -slw
use strict;

my %fhs;
my $d = '|';
while(<>) {
    my ($first, $rest) = m[(^.*?)\Q${d}\E(.*$)];
    my $fh = $fhs{$first} ||= do {
        IO::File->new('>>', $first) || die "Couldn't open $first:$!"
    };

    $fh->print($rest);
}