You want to use eq for checking the equality of strings.

perlop says:

Binary ``=='' returns true if the left argument is numerically equal to the right argument.
Binary ``eq'' returns true if the left argument is stringwise equal to the right argument.

Update! The docs for Posix say this:

strcmp() is C-specific, use eq or cmp instead, see the perlop manpage.

2nd update diotalevi has a better answer since I didn't take into account that you only want to compare the first 36 characters.