I know one shouldn't use use a variable variable name, so I decided to put my variable variable names in a hash instead, thus:

#!/usr/bin/perl
use strict;
use warnings;

my %intros = ();
open my $fh, '<', 'big_pipe_delimited_file' or die $!;
while (<$fh>) {
  my ($intro) = /^(.*?)\|/;
  $intros{$intro} = 1;
}

my %introsh = ();
for (keys %intros) {
  open $introsh{$_}, '>', 'big_pipe_delimited_file_' . $_ or die $!;
}

seek($fh, 0, 0) or die $!;
while (my $line = <$fh>) {
  my ($intro) = $line =~ /^(.*?)\|/;
  print $introsh{$intro} $line;
}
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Perl objects to my use of $introsh{$intro} in the print statement: Scalar found where operator expected at foo.pl line baz, near "} $line" (Missing operator before $line?). What can I do instead?