Interesting timing... I was just working this out too....found the answer on google. :-) Anyways, just for kicks, here is the way I used it.... I had a few dictionary files, which I wanted to split and merge into "alphabetical files" , like a, b, c, etc so I could search for a word faster. So I need to open filehandle variables pointing to a..z.

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

my $file = shift;
open(FH, "< $file") or die $!;

my %fh;

foreach my $let('a'..'z'){
   open( $fh{$let}," >> letters/$let");
}
                              
while(<FH>){                  
my $count = 0;                
my $word = $_;                
chomp $word;                  
$word = lc $word;
$word =~ s/[[:^print:]\s+]+//g; #only printable characters 
                
#skip words with apostrophe, dashes, spaces, or a .w ending 
my $word1 = $word;
$count = $word1 =~ tr/\'-_ &,.0-9//;
if($count > 0){next}

 my $let = substr($word, 0, 1);
   if (!defined $fh{$let}){print $word;next}
       else{
   print { $fh{$let} } "$word\n";}
}
__END__
[download]

and then to "uniqify the files

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

foreach my $file('a'..'z'){
   system("sort -u letters/$file > letters/$file.txt");
}
__END__
[download]