#!/usr/bin/env perl
  # Copyright 2010-2011 Microsoft Corporation
  
  # Licensed under the Apache License, Version 2.0 (the "License");
  # you may not use this file except in compliance with the License.
  # You may obtain a copy of the License at
  #
  #  http://www.apache.org/licenses/LICENSE-2.0
  #
  # THIS CODE IS PROVIDED *AS IS* BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
  # KIND, EITHER EXPRESS OR IMPLIED, INCLUDING WITHOUT LIMITATION ANY IMPLIED
  # WARRANTIES OR CONDITIONS OF TITLE, FITNESS FOR A PARTICULAR PURPOSE,
  # MERCHANTABLITY OR NON-INFRINGEMENT.
  # See the Apache 2 License for the specific language governing permissions and
  # limitations under the License.
  
  # converts an utt2spk file to a spk2utt file.
  # Takes input from the stdin or from a file argument;
  # output goes to the standard out.
  
  if ( @ARGV > 1 ) {
      die "Usage: utt2spk_to_spk2utt.pl [ utt2spk ] > spk2utt";
  }
  
  while(<>){ 
      @A = split(" ", $_);
      @A == 2 || die "Invalid line in utt2spk file: $_";
      ($u,$s) = @A;
      if(!$seen_spk{$s}) {
          $seen_spk{$s} = 1;
          push @spklist, $s;
      }
      $uttlist{$s} = $uttlist{$s} . "$u ";
  }
  foreach $s (@spklist) {
      $l = $uttlist{$s};
      $l =~ s: $::; # remove trailing space.
      print "$s $l
  ";
  }