in reply to
Re^2: Annoying 'Use of uninitialized value in concatenation' warning
in thread Annoying 'Use of uninitialized value in concatenation' warning
If you use diagnostics perl will tell you which category the warning belongs to. For example, printing an uninitialised variable yields (the category is in bold):
Use of uninitialized value $x in print at
/home/bri/foo.pl line 14 (#1)
(W uninitialized) An undefined value was used as if it were already
defined. It was interpreted as a "" or a 0, but maybe it was a mistake.
To suppress this warning assign a defined value to your variables.
lists all of perl's warning and error messages.