I heard this from the mail clerk at my barracks in Korea in 1971. I forget his name but he was a very cool guy. he would sing this when he came with the mail call. however the lyrics were a little different -
how have you been my darlin children
while I've been away so long it seems
you all are strangers though it seems like I know you
from the way that you treat me
and offer to feed me
and ask me to sit and stay for awhile
... something like that.

it was a beautiful reprieve from a rather awful experience in the Army that ended up saving me from a life wasted in drugs. I'll always remember him for this song.