Question

I would like to capture the complete output of the install.packages command in a variable. However, the messages that are printed during the installation are a result of calling system() with intern=FALSE. As a result they are not really messages/warnings/print. Is there any way to capture this information into a variable? E.g.

> sink(tempfile())
> bla <- suppressMessages(suppressWarnings(capture.output(system('whoami'))));
jeroen

Or:

> sink(tempfile())
> bla <- suppressMessages(suppressWarnings(capture.output(install.packages("XML"))));

Still prints everything to screen…

Answer 1

You can launch a separate R process:

system( "Rscript -e 'install.packages(\"XML\")'", intern=TRUE )