O enlightened ones: I have many 12 bit ints which I want to output to a file. I have a way which works but is misserable in its ugliness. Who has a beautiful way to mix two 12 bit ints into three chars and then to read them back? Here's my ugly-bags-of-mostly-water code: 
sub c_out {
 my $_=shift;
 my $final=shift;
 if(defined($c_out_store)) {
  print F2 pack('H*',sprintf('%03x%03x',$_,$c_out_store));
  undef $c_out_store;
 } elsif($final) {
  print F2 pack('H*',sprintf('%03x%03x',0,$_));
 } else {
  $c_out_store=$_;
 }
}

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and then to read: 
 while($usedouble || !eof($file_in)) {
  if($usedouble) {
   $new_code=$double; $usedouble=0;
  } else {
   $r=read($file_in, $double, 3); ($double)=unpack(N,"\000$double");
   $new_code=$double & 0xfff; $double >>= 12; $usedouble=1;
  }
  # etc
 }

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In reply to 12 bit ints pairs into 3 bytes by jhanna

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