if (require(hapmapsnp5)){
  path <- system.file("celFiles", package="hapmapsnp5")
  ## only the filenames
  list.celfiles(path)
  ## the filenames with full path...
  ## very useful when genotyping samples not in the working directory
  list.celfiles(path, full.names=TRUE)
}else{
  ## this won't return anything
  ## if in the working directory there isn't any CEL
  list.celfiles(getwd())
}Run the code above in your browser using DataLab