# exercise 4.1 by erikt(at)science.uva.nl

SOFTWARE

# read the first phrase
print "Please enter the first phrase: ";
$phrase1 = <STDIN>;
if (not defined $phrase1) { $phrase1 = ""; }
chomp($phrase1);

# repeat until the first phrase is empty
while ($phrase1 ne "") {

   # read the second phrase
   print "Please enter the second phrase: ";
   $phrase2 = <STDIN>;
   if (not defined $phrase2) { $phrase2 = ""; }
   chomp($phrase2);

   # remove white space
   $phrase1 =~ s/\s+//g;
   $phrase2 =~ s/\s+//g;

   # convert upper case to lower case
   $phrase1 =~ tr/A-Z/a-z/;
   $phrase2 =~ tr/A-Z/a-z/;

   # extract characters and put them in the same order by sorting them
   @chars1 = split(//,$phrase1);
   $chars1 = join("",sort(@chars1));
   @chars2 = split(//,$phrase2);
   $chars2 = join("",sort(@chars2));

   # compare phrases
   if ($phrase1 eq $phrase2) { print "These phrases are identical\n"; }
   elsif ($chars1 eq $chars2) { print "These phrases are anagrams\n"; }
   else { print "These phrases are not related\n"; }

   # read the first phrase
   print "Please enter the first phrase: ";
   $phrase1 = <STDIN>;
   if (not defined $phrase1) { $phrase1 = ""; }
   chomp($phrase1);
}

# final message
print "Thank you for using this program!\n";


TEST

erikt@stuwww:~$ perl -w 41.pl
Please enter the first phrase: test
Please enter the second phrase: TEST
These phrases are identical
Please enter the first phrase: d o r m i t o r y
Please enter the second phrase: dirty room
These phrases are anagrams
Please enter the first phrase: caramba
Please enter the second phrase: mascara
These phrases are not related
Please enter the first phrase: 
Thank you for using this program!