my %merge=(%hash1, %hash2); # ?
# how 'bout key clashes?
my %merge2=(%hash2, %hash1);
# will be different => MORE DETAILS - MORE DETAILS!!
[download]

PS: letting apart the fact that the question -if I understood it correctly- is extremely trivial and -still if I understood it correctly- I'd recommend reading some introductory perl document or tutorial before proceeding, I find that your "code" didn't help - to understand correctly your question. If you have some real (pseudo-)code that is suitable to illustrate a problem, then show it, else do not contribute to line noise: help people to help you!