$_ = "KL5-8590";

# for now, we'll match against the default $_ variable
if (/KL5-[0-9]{4}/) {
  print "I think this is a fake number\n";
}
elsif (m<KLM>) {
  print "Is there an airline involved?\n";
}

# -----

if (/kl5-[0-9]{4}/i) {
  print "I think this is a fake number\n";
}

# -----

$_ = "My favorite cop is Ponch\n\nBut some crazy people like John.";

if (/Ponch.*John/s) {
  print "Ponch is mentioned somewhere on this page before John\n";
}

# -----

$_ = "The number on the wall was 867-5309, Tommy said";

if (/\b[0-9]{3}-[0-9]{4}\b/) {
  print "This looks like a telephone number\n";
}

# OR:
if (/
  \b       # word boundary
  [0-9]{3} # first 3 digits
  -        # customary hyphen
  [0-9]{4} # next 4 digits
  \b       # word boundary
/x) {
  print "This looks like a telephone number\n";
}

# -----

$_ = "My favorite cop is Ponch\n\nBut some crazy people like John.";

if (/
   ponch
   .*
   john
/six) {
  print "Ponch is mentioned somewhere on this page before John\n";
}

# -----

my $tv_show = "The Brady Bunch";
if ($tv_show =~ /brady/i) {
  print "Who's your favorite Brady?\n";
}

# reading through a piped-in file
while (<>) {

  if (/\b(\w+)\s+(\w+)\b/) {
    print "word 1 was $1 and word 2 was $2\n";
  }

}