$ perl -MText::ParseWords=quotewords -nle 'print join " ", map { $_ eq ";" ? "&&" : $_ } quotewords qr/\s+/, 1, $_'
cd / ; /path/to/R/R_latest --vanilla --args "fName='rGSDPlan';jobCode=682718;jobId=6827181;" < job682718.R > job_6827181.txt
cd / && /path/to/R/R_latest --vanilla --args "fName='rGSDPlan';jobCode=682718;jobId=6827181;" < job682718.R > job_6827181.txt