/usr/share/xastir/scripts/split_gnis.pl is in xastir 2.1.0-1.
This file is owned by root:root, with mode 0o755.
The actual contents of the file can be viewed below.
| 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 | #!/usr/bin/perl -w
#
#
# split_gnis.pl -- 2004 Mar 15 -- jmt@twilley.org
# This script is designed to break large GNIS datapoint files
# into smaller chunks and will dispose of extra whitespace properly.
# It is based on a bash script written by kc9asi@arrl.net.
# The filenames used as input should be put on the command line.
while (<>) {
  next unless /[A-Z][a-z]/;
  s/\s+$//;
  my $line = $_;
  my @fields = split /\|/, $line;
#  print "Fields is @fields\n";
  # key is "state county"
  my $key = $fields[1] . " " . $fields[4];
  $key =~ s/ /_/g;
  push @{$county{$key}}, $line;
}
foreach $elem (keys %county) {
  my $name = $elem . ".gnis";
  open(OUT,">$name");
  foreach $line (@{$county{$elem}}) {
    print OUT $line, "\n";
  }
  close(OUT);
}
 |