in reply to Single line insert to the start of a file

Assuming a *nix system, and the existence of a real-world problem to be solved rather than a homework problem in a particular language:

head -1 file1 >/tmp/file.$$; cat file2 >>/tmp/file.$$; mv /tmp/file.$$ file2

Aaron B.
Available for small or large Perl jobs; see my home node.