Ruby auto deleting temp file?

Question

I'm confused. Here's my code:

require 'csv'                                                               
require 'tempfile'                                                          

f = Tempfile.new('csv','/tmp')                                                 
f.write 'just wanna test'                                                       
f.close                                                                        

p f.path 

If I open the output path, it is empty.

I think this is because that the TempFile got automatically removed from the file system each time the ruby session exits. However, how do I know exactly when the file got deleted? Because I'm thinking to use it to create temp file within my rails app, I'm afraid if the file got deleted before it is used.

Answer 1

I've seen Tempfile being garbage collected in the same process when I created many temp files to be zipped. In the code below, if I didn't store the Tempfile handles in the handles array I would get runtime error (Errno::ENOENT: No such file or directory @ rb_sysopen) when the Zip::File.open block closes:

handles = []
Zip::File.open(zip_file.path, Zip::File::CREATE) do |zip|
  # there are hundreds of @foos to iterate over
  @foos.each do |foo|
    cit_filename = generate_some_unique_filename
    cit_file = Tempfile.new(cit_filename)
    handles << cit_file
    cit_file.puts('some text')
    cit_file.close
    zip.add(cit_filename, cit_file.path)
  end
end # <- runtime error would have thrown at this point
handles = nil