#!/usr/bin/perl -w
# turn on strict forcing definition of variables and subs/functions
  use strict;
#
# Declare Function/Sub Routines
sub Searchme; #returns -1 if substring not found
# used with @Search_Array defined later.
sub Removechar; #returns original line with character removed.
# Two parameters are passed, the line and the character to remove.
# We are using this to remove doublequotes from the input line.
sub Checknotspacesonly; #returns emptystring from input line, if line
# is only spaces. The only parameter passed is the input line.
# Declare Variables
  my @Search_Array = ("email", "website");
  # This is what will be searched for. A line
  # that matches any of the substrings contained in the 
  # Search_Array will be filetered out.
  my $infile =  ""  ;  # input file
  my $outfile =  "" ;  # output file
  my $line = ""    ;  # line of input file
  my $len = 0;        # Used for getting length of a string.
  my $getresult = -1; # -1 will denote not found after searching for
#                        a substring within a string.
#Sub Routine / Function Section
sub Searchme # Returns  -1 if Substring not found in input line
             # Otherwise it returns a number of zero or greater.
 {
  my $j = 0;  #iteration loop scalar counter
  my $result = -1;     # used for checking for substring
                       # A "-1" denotes not found.
# Given an input line search for elements in the Search_array.  
  my ($inline, @Search2_array) = @_;
  my $knum = 0; #Set and define default number of Substrings to search.
  $knum = scalar@Search2_array; #Get number of elements (substrings)
                               # to search line for.
  # Note we must subtract -1 from $knum so we do not go past the 
  # end of the search array. 
     for ( $j = 0; $j <= ($knum -1 ); $j++)
     {
     $result =  index($inline, $Search2_array[$j]);
     # A value of -1 is returned for not found.
     if ($result >= 0)
      {return $result; next;} # Exit prematurely found a substring 
                              # that matches. 
     }
     return $result; # if we get here no matching substrings.
}  # End sub Searchme
sub Removechar # Returns the line with the character removed.
#  The input line and the character to remove is passed in as a 
#  character string.
  {
   my ($inline, $chartoremove) = @_; 
   $inline  =~ s/$chartoremove//g; 
   return $inline;
  }
#end sub Removechar
sub Checknotspacesonly # A line is passed in and its length is checked.
# A string equal to spaces only of this length is created. If the
# strings matched, the line is returned as null string to be ignored,
# that is treated later as blank.
 {
   my ($inline) = @_; 
   my $len = 0;        # assume blank string of zero length.
   my $spacestr = "";  # assume blank string
   my $j =0; # iteration loop scalar counter.
   $len = length($inline);
   # Use concatenation operator to create string of desired length
   # containing only spaces.
   for ($j =0; $j <= ($len -1);$j++)
   {
      $spacestr = $spacestr. " ";
   }
   if ($inline eq  $spacestr)
     {
      $inline = ""; # set line returned to null string for all spaces
     }
   return $inline;
 }
# End sub Checknotspacesonly
# End Subroutine Function Section
#
# Begin Main Program Section ###################################
#
# Usage:   perlparselabel input_filename output_filename
#              input_file_name  will be the name of the input file 
#              to process. output_file_name will be the output file.
#              
# This program will take an input file and eliminate the lines that 
# contain blanks, the word "email" or the word "website". This is so
# that a mailing list can be generated for US Postal mail. This is a
# simplified version of a program used in real life. The output 
# file name will be whatever you chose to call it. 
# i.e.   ./perlparselabel infile.txt outfile.txt

	$infile = shift(@ARGV);
# Shift arguement call array to left to getinput file
	open(INFILE,$infile) || die "Couldn't open input file $! \n";
	$outfile = shift(@ARGV);
# Shift arguement call array to left to get output file
open (OUTFILE, ">$outfile") or die "$! error trying to overwrite";	
       
       while(<INFILE>)  # Keep Reading file to end
{        
 # Good practice to store $_ value because
 # subsequent operations may change it.
              $line = $_; # get input line from reading file.
 # Good practice to always strip the trailing
 # newline from the line.
              chomp($line);
              $getresult = Searchme($line, @Search_Array);
              if ($getresult >= 0 )
                {next;} # leave while loop do not write this line.
              # Remove the doublequote using function created.
              $line = Removechar ($line, '"' );
              $line = Checknotspacesonly ($line);
              $len = length($line);
              if  ($len > 0) { # check not blank line
                         print    OUTFILE " $line  \n";  
              }                        
#end of while loop block
}
close(INFILE);
close(OUTFILE);
# End Main Section **************************
exit;