Function from the package [poppr](https://github.com/poppr/poppr) that serves as a wrapper for `file.choose()`, `file.path()`, and `list.files()`. It will allow the user to grab multiple files for import into R with their gui.

getfile.r

#==============================================================================#
# Usage: 
# x <- getfile() # for a single file.
# x <- getfile(multi = TRUE) # for multiple files
# x <- getfile(multi = TRUE, pattern = "^.+?csv$") # grabs all *.csv files. 
# setwd(x$path)
# read.csv(x$files)
#==============================================================================#

getfile <- function(multi=FALSE, pattern=NULL, combine=TRUE){
  # the default option is to grab a single file in the directory. If multFile is 
  # set to TRUE, it will grab all the files in the directory corresponding to any
  # pattern that is set. If there is no pattern, all files will be grabbed.
  if (multi==TRUE){
    # this sets the path variable that the user can use to set the path
    # to the files with setwd(x$path), where x is the datastructure 
    # this function dumped into.
    pathandfile <- file.path(file.choose())
    path <- dirname(pathandfile)
    if (!is.null(pattern)){
      pat <- pattern
      x <- list.files(path, pattern=pat)
    }
    else {
      x <- list.files(path)
    }
  }
  else {
    # if the user chooses to analyze only one file, a pattern is not needed
    pathandfile <- file.path(file.choose())
    path <- dirname(pathandfile)
    x <- basename(pathandfile)
  }
  if(combine == TRUE){
    x <- paste(path, x, sep="/")
  }
  filepath <- list(files=x, path=path)
  return(filepath)
}