#delimiter for Metacharacters ^ $ ( ) \ | @ [ { ? . + * 
$_ = "c:/mywork/hangman";
if (m/c:\/mywork\/hangman/) 
{ 
    print "Found the hangman game!\n\n" 
}  

# + causes the preceding character to match at least once
$content = "hotdog";
if ($content =~ m/do+g/) 
{ 
    print "found do+g : $content\n\n"; 
}

$content = "hotdooooooooooooog";
if ($content =~ m/do+g/) 
{ 
    print "found do+g : $content\n"; 
	print "pattern that match: $&\n\n";  #$& stores pattern matched
}

#* metacharacter is similar to the + metacharacter, but it causes the preceding character to be matched zero or more times.
$content = "hotdg";
if ($content =~ m/do*g/) 
{ 
    print "found do*g : $content\n\n"; 
}

$content = "hotdoooooooooooooog";
if ($content =~ m/do*g/) 
{ 
    print "found do*g : $content\n\n"; 
}

#exact match, {n,m} n is the minimum number of matches, m is the maximum number of matches
$content = "xxxwing";
if ($content =~ m/x{2,4}/) 
{ 
    print "found x{2,4} : $content\n\n"; 
} else {
	print "not found x{2,4} : $content\n\n";
}

#[] "any of these characters."
$content = "xxxwing";
if ($content =~ m/[a-e]{2,4}/) 
{ 
    print "found [a-e]{2,4} : $content\n\n"; 
} else {
	print "not found [a-e]{2,4} : $content\n\n";
}

$content = "xxxwing";
if ($content =~ m/[x-z]{2,4}/) 
{ 
    print "found [x-z]{2,4} : $content\n\n"; 
} else {
	print "not found [x-z]{2,4} : $content\n\n";
}

#if a caret (^) occurs as the first character of a character class, the character class is negated.
#[^A-Z] Matches non-uppercase-alphabetic characters.
$content = "xxxwing";
if ($content =~ m/[^A-Z]{2,4}/)   
{ 
    print "found [^A-Z]{2,4} : $content\n\n"; 
} else {
	print "not found [^A-Z]{2,4} : $content\n\n";
}

#\w A word character; same as [a-zA-Z0-9_]
$content = "x1X2x3wing";
if ($content =~ m/\w{2,10}/) 
{ 
    print "found \w{2,10} : $content\n\n"; 
} else {
	print "not found \w{2,10} : $content\n\n";
}