How can I make R read my environmental variables?

Question

I am running R on EC2 spot instances and I need R to terminate the instance and cancel the spot request once the script has run.

For that I have set the \"Request ID

Answer 1

You want Sys.getenv() as in Sys.getenv("PATH"), say.

Or for your example, try

SIR <- Sys.getenv("SIR")   
system(paste("ec2-cancel-spot-instance-requests",  SIR))

As for setting variables at startup, see help(Startup) to learn about ~/.Renvironment etc