or is identical to the operator || except that with ||, function calls need parentheses, while with or they don't.

there are other differences than that. consider:

tina@lux:~> perl -wle'
@a = qw(a b c);
@b = @a or die;
@c = @a || die;
print "(@b) (@c)"'
(a b c) (3)
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