Get package versions (by default use all attached packages)

package_versions.R

package_versions <- function(packages=NULL, base=FALSE, sort=FALSE) {
    #' Determine package versions.
    #' 
    #' @param packages Packages to query; if not specified (or \code{NULL}),
    #' all currently attached packages are queried.
    #' @param base If \code{TRUE}, include the base package (R version).
    #' @param sort If \code{TRUE}, sort package names alphabetically. 
    #' @return Data frame with package names and corresponding versions.
    if (is.null(packages))
        packages <- names(sessionInfo()$otherPkgs)
    if (base)
        packages <- c("base", packages)
    if (sort)
        packages <- sort(packages)
    if (!is.null(packages)) {
        tmp <- data.frame(sapply(sapply(packages, packageVersion, simplify=FALSE), as.character))
        colnames(tmp) <- "version"
        data.frame(package=rownames(tmp), version=tmp[1], row.names=NULL)
    }
}