unshift - prepend more elements to the beginning of a list
Does the opposite of a shift. Or the opposite of a push, depending on how you look at it. Prepends list to the front of the array,
and returns the new number of elements in the array.
unshift(ARGV, '-e') unless $ARGV =~ /^-/;
LIST is prepended whole, not one element at a time, so
the prepended elements stay in the same order. Use reverse to do the