Advanced Perl Programming

Typeglobs

1. Typeglobs assignment aliases identifiers. In the following example, all identifiers named a (scalar, array, hash, subroutine, filehandle, format) are also available as b:

   *a = *b ;     # Alias
   $b = 10;      # Same as modifying $a
   b();          # Same as calling a()

2. Selective aliasing:

   *a = \$b ;    # Only $a aliased to $b

3. Constants:

   *a = \10;     # Alias a typeglob to a reference to a constant
   $a = 20;      # Run-time error - "Attempt to modify read-only variable"