If you want to insert a line
at the top (or anywhere for that
matter) of a file within a shell
script, use the ed editor.
EXAMPLE:
string="hello"
ed << EOF
e any_file
1i
${string}
NOTE: All tips provided are USE AT YOUR OWN RISK. Tips are submitted
by various unix admins around the globe. UGU suggest you read and
test each tip in a non-volitile environment before placing into
production.