[R] How to execute multiple R scripts sequentially in unix background

[Yong Wang]

Dear list

I need to 1) run several R scripts sequentially due to results waiting
and 2) run them in unix background since my ssh frequently timeout for
some reason.
if paste following codes to unix

R --vanilla script1 &
R --vanilla script2 &
R --vanilla script3 &

will result in simultaneous instead of sequential execution of the
three scripts.

source() might be an alternative, however, I am not clear how to run
it in the background.

Thanks

yong