Get package name when installing from source

Question

I know you can install a .tar.gz or .zip from source using the following.

install.packages(SOURCE_FILE, repos = NULL, type="source")

I want to be able to determine the name of the package that's being installed. So for instance we could download this amazing package: https://github.com/Dasonk/findPackage/tarball/master?download .

This would give us a .tar.gz called Dasonk-findPackage-61907b1.tar.gz . We could actually rename it to beep.tar.gz and still install as:

 install.packages("beep.tar.gz", repos=NULL, type="source")

How can I get the actual package's name that was installed. I thought I could use capture.output but that does not seem to work either. So after using install.packages I'd like to know "findPackage" was just installed.

Answer 1

I hate this but it's all I could come up with:

package_name <- function(package) {
    temp <- tempdir()
    untar(package, exdir = temp)
    out <- c(read.dcf(list.files(temp, pattern="DESCRIPTION", 
        recursive=TRUE, full.names=TRUE), "Package"))
    unlink(temp, recursive = TRUE, force = FALSE)
    out
}

package_name("beep.tar.gz")

Answer 2

If you're willing to install the package, then I think the easiest way seems like just getting the list of installed packages before and after:

# Grab previously installed packages
start.packages <- installed.packages()[,1]

# Install your new package
install.packages("beep.tar.gz", repos=NULL, type="source")

# Find all new packages
setdiff(installed.packages()[,1], start.packages)

Obvious downsides are that you need to install the new package, and that you'll also get all the newly installed dependencies.