split big csv into multiple smaller files

split_csv.rb

   tmp_dir       = "#{RAILS_ROOT}/tmp/"
   original_file = "file.csv"
   #create temporary dir
   sh "mkdir #{tmp_dir}"

   # create a temporary file containing the header without
   # the content:
   sh "head -n 1 #{original_file} > #{tmp_dir}/header.csv"

   # create a temporary file containing the content without
   # the header:
   sh "tail +2 #{original_file} > #{tmp_dir}/content.csv"

   # split the content file into multiple files of 10000 lines each:
   sh "split -l 10000 #{tmp_dir}/content.csv #{tmp_dir}/prefix_"

   # loop through the new split files, adding the header
   # and a '.csv' extension:
   sh "for f in #{tmp_dir}/prefix_*; do cat #{tmp_dir}/header.csv $f > $f.csv; rm $f; done;"