Function to convert an existing R-forge svn repository to git.

rforge2git.R

#' Convert the trunk of an R-forge SVN repository to git
#' 
#' This function to reorganizes an existing svn repository from R-forge to a git repository. One 
#' or both of the repository paths can be specified. Assumes that git-svn has been installed, and 
#' that git can be called through the command line/terminal. Windows users may have to 
#' add the git binary location to their ENVIRONMENTAL VARIABLES. 
#' 
#' @param svn.repo a string pointing to the R-forge svn repository. Generally of the form 
#' \code{svn://svn.r-forge.r-project.org/svnroot/package/} or 
#' \code{svn+ssh://developername@@svn.r-forge.r-project.org/svnroot/package/}. This will reorganize 
#' the format into something more suitable for github or gitorioius
#' @param git.repo a remote location to push the git repository to
#' @param rev_num specific revision number. Use to make a specific cloning point from the svn
#' repo. Default is to clone the entire repo
#' @param clean logical; remove extra material in the svn repo?
#' 
#' @examples
#' \dontrun{
#' 
#' # convert R-forge tableplot to git
#' svn.repo <- 'svn://svn.r-forge.r-project.org/svnroot/tableplot/'
#' rforge2git(svn.repo=svn.repo)
#' 
#' # publish to an empty git remote location 
#' # (Note: this will not work on your computer since you must be an admin for the git repo) 
#' git.repo <- 'https://github.com/philchalmers/svntableplot.git'
#' rforge2git(git.repo=git.repo)
#' 
#' #run both steps at once
#' rforge2git(svn.repo=svn.repo, git.repo=git.repo)
#' 
#' }
rforge2git <- function(svn.repo = NULL, git.repo = NULL, rev_num = NULL, clean = TRUE){
    
    if(is.null(svn.repo) && is.null(git.repo))
        stop('One or both of svn.repo or git.repo must be specified.')
    if(!is.null(svn.repo)){
        dir <- dir()
        if(is.numeric(rev_num)){
            gc <- sprintf('git svn clone -r %i:HEAD', rev_num)
        } else gc <- 'git svn clone '
        system(paste0(gc, svn.repo))
        reponame <- setdiff(dir(), dir)
        setwd(reponame)
        if(clean) system(paste0(c('rm -f -r', setdiff(dir(), 'pkg')), collapse=" "))
    	is_win <- Sys.info()['sysname'] == 'Windows'
    	if(is_win){
    	    wd <- getwd()
    	    wd <- gsub('/', '\\\\', wd)
    	    system(paste0('xcopy pkg ', paste0(wd, ' /s /e /h')))
    	    system('rm -f -r pkg')
    	} else {
    	    system('git mv pkg/* pkg/.[a-zA-Z]* .')
    	    system('rmdir pkg/')
        }
        system('touch README.md')
        system('git add --all')
        system('git commit -m "fixup initial migration from svn"')
    }
    
    # option to publish git repo
    if(!is.null(git.repo)){
        system(paste0('git remote add origin ', git.repo))
        system('git push -u origin master')
    }
    return(invisible(NULL))
}