#!/usr/bin/perl

if ($#ARGV == -1)
{
print("Please enter filename: ");
$filename = <STDIN>;
chomp ($filename);
}
else
{
 $filename = $ARGV[0];
}

if ($filename -r && $filename=~m/^[_a-zA-Z]/) #if filename is readable AND matches.....
{
open (READFILE, $filename)|| die "Failed to open $filename: $!";
}

if ($filename !~ m/\.txt$/i) #if filename does not end with .txt then add to filename
{
$filename .= ".TXT";
}

my $filecontents;
{
    local undef $/;
    $filecontents = <READFILE>;
}
close <READFILE>;  #slurps the whole file into a variable


$sentences = 0;
my @characters = $filecontents =~ m/./g;   # puts a copy of each match into @characters
my($ch);
my $CharCount = scalar @characters;        # this counts the number of elements in @characters
my @words = $filecontents =~m/[a-zA-Z]\s/g;# matches a char followed by a white space character globally

while ($ch = getc(READFILE))
{
 # count sentences:
 if ($ch eq "?" || $ch eq "!" || $ch eq ".")
 # if character is one of the three end of sentence markers
 {
  $sentences++;
 }
}

while ($ch = getc(READFILE))
{
	$CharCount
		{ $ch }++;
}



for (@characters)
 {
    print "There are $_ \n characters";
 }										   
    print "There are $sentences sentences";										   



# output data
# open(OUT, ">data1.txt") || die "data1.txt not open: $!";
# close(OUT);