$ perl -le '
$str = q{bit_of_a_pigs_ear};
print
   q{_ear} eq substr( $str, -3 )
   ? q{Match found}
   : q{No match};
print
   q{_ear} eq substr( $str, -4 )
   ? q{Match found}
   : q{No match};'
No match
Match found