[[Perl]]
 
 	@txt = `ls *txt`;
 	foreach $file (@txt){
 		#mecab でわかち書き
 	        @mecab = `mecab -O wakati $file`;
 		#DF用に初期化
 	        undef %TmpWords;
 		#単語の出現頻度を求める。
 	        foreach(@mecab){
 	                chomp;
 	                @tmp = split(/\s/,$_);
 	                foreach(@tmp){
 	                        $Words{$_}++;
 	                        $TmpWords{$_}++;
 	                }
 	        }
 	        @TmpWords = sort{$TmpWords{$b}<=>$TmpWords{$a}} keys %TmpWords;
 	        foreach(@TmpWords){ $DF{$_}++;}
 	}
 	@Words = sort{$Words{$b}<=>$Words{$a}} keys %Words;
 	@DF = sort{$DF{$b}<=>$DF{$a}} keys %DF;
 	#出現頻度の書き込み
 	open(OUT,">result.txt");
 	foreach(@Words){ print OUT "$_\t$Words{$_}\n";}
 	close(OUT);
 	#DFの書き込み
 	open(OUT,">DFresult.txt");
 	foreach(@DF){print OUT "$_\t$DF{$_}\n";}
 	close(OUT);