ruby - How to write an image to filesystem in rails 3.1.1? -

i feel should close, can't work quite right.

i'm sending image using filetransfer phonegap app rails app (3.1.1 ruby 1.8.7 btw).

i want write file filesystem.

this params hash:

parameters: {"file"=>#<actiondispatch::http::uploadedfile:0x7f1e2baa94e8 @tempfile=#<file:/tmp/rackmultipart20120607-5707-owzii5-0>,  @headers="content-disposition: form-data; name=\"file\"; filename=\"image.jpg\"\r\ncontent-type: image/jpeg\r\n",  @content_type="image/jpeg", @original_filename="image.jpg">} 

basically, can access file through params[:file]. need write image on filesystem. don't have model image correspond to, don't need paperclip. right now, best come this:

open(params[:file]) |image|   file.open("theiamge.jpg","wb"){|file| file.puts image.read } end 

this error get:

typeerror (can't convert actiondispatch::http::uploadedfile string): 

edit:

so, rather odd. can these commands working in irb:

 file.open('newimage.jpg', 'wb') |f|    f.write file.open('oldimage.jpg').read  end 

however, doesn't work:

 file.open("ihatedetails.jpg",'wb') |f|    f.write file.open(params[:file]).read  end 

i error: typeerror (can't convert actiondispatch::http::uploadedfile string):

i'm using ruby 1.9.3 in irb, these commands should same...

so i'm stumped right now.

the code should be:

file.open("ihatedetails.jpg",'wb') |f|   f.write params[:file].read end 

or file.open("ihatedetails.jpg",'wb') { |f| f.write params[:file].read } in 1 line.