[R] getting package version inside .First.lib

[Roger D. Peng]

This is what I use for all my packages, which I believe handles multiple 
versions of the same package being installed:

.First.lib <- function(lib, pkg) {
     ver <- read.dcf(file.path(lib, pkg, "DESCRIPTION"), "Version")
     ver <- as.character(ver)
     ...
}

-roger

Adrian Baddeley wrote:
> Greetings - 
> 
> Is it possible, inside .First.lib,
> to find out the version number of the package that is being loaded?
> 
> If only one version of the package has been installed,
> we could scan the DESCRIPTION file, something like
> 
> .First.lib <- function(lib, pkg) {
>     library.dynam("spatstat", pkg, lib)
>     dfile <- system.file("DESCRIPTION", package="spatstat")
>     ttt <- scan(dfile, what="", sep="^M", quiet=TRUE)[2]
>     vvv <- strsplit(ttt," ")[[1]][2]
>     cat("spatstat version number",vvv,"\n")
> }
> 
> but even this does not seem very safe (it makes assumptions about the
> format of the DESCRIPTION file).
> 
> Is there a better way?
> 
> thanks
> Adrian Baddeley
> 
> ______________________________________________
> R-help at stat.math.ethz.ch mailing list
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html
> 

-- 
Roger D. Peng
http://www.biostat.jhsph.edu/~rpeng/