customer

This program loads a three element text file into two hashes and then allows you to look for the keys Phone number or Email address in the hashes to view the customer data orginally in the text file

#! /usr/bin/perl -w

# Program to read a file "customers.txt" with three elements
#  (name, phone, email)and place it into two hashes (%Phone, %Email).
#  Then it ask for a phone number. If a number is entered the customer
#  information will be printed. If no number is entered it will then ask
#  for an email address. If "q" is entered for either the number or the
#  address the program will quit.

# open the file
open (PH, "customers.txt") or die "Cannot open customers.txt: $!\n";
# place data into the two hashes
while (defined ($data = )) {		# While data
  chomp $data;
#		Look for one or more word characters (\s+). Three will
#		be found [0,1,2]. $number will become [1] and $email
#		will become [2].
  ($number, $email) = (split (/\s+/,$data) )[1,2];
#		$number becomes the key for %Phone
  $Phone{$number} = $data;
#		$email becomes the key for %Email
  $Email{$email} = $data;
}
close (PH);					# Close the file

print "Type 'q' to exit\n";
while (1) {					# While true
  print "\nNumber? ";
  $number = ;  chomp($number);		# Get the number key
  $address = "";
  if (! $number) {				# If no number get the email key
    print "E-Mail? ";
    $address = ;   chomp ($address);
  }

  next if (! $number and ! $address);		# If no number or address
  last if ($number eq 'q' or $address eq 'q');	# If either is "q"

  if ($number and exists $Phone{$number} ) {	# If number use %Phone
    print "Customer: $Phone{$number}\n";
    next;
  }

  if ($address and exists $Email{$address} ) {	# If addresse use %Email
    print "Customer: $Email{$address}\n";
    next;
  }
  print "Customer record not found. \n";	# Number or address not found
  next;
}
print "\nAll done.\n";				# "q" was entered