I think it's easiest in python
Code:
oldform1 = "function getDBBackend()\n{\n ..."
oldform2 = """function getDBBackend()
{
} // getDBBackend"""
filenames = ["file1", "file2", ]
for fname in filenames:
data = file(fname).read()
data = data.replace(oldform1, newform)
data = data.replace(oldform2, newform)
file(fname, "w").write(data)
with appropriate values of filenames, oldform{1,2} and newform.
hth --Jonas