Studying Professor Dalgaard's code a bit, here is a little hack that returns the desired result on Unix-alikes: From>* system2("echo", env = c("VAR='Hello World'"), args = c("$VAR"))*to>* system2("echo", env = c("VAR='Hello World';"), args = c("$VAR"))*Hello World That is, adding the semi-colon effectively transforms pd$ VAR="foo" echo $VAR to pd$ VAR="foo"; echo $VAR Maybe this doesn't apply to more complicated situations,though. luke [[alternative HTML version deleted]]