From: Tim Hunter <cyclists@...>
Date: 2005-08-04T07:21:05+09:00
Subject: Re: RMagick problem

Joe Van Dyk wrote:

> The following Rails/Ruby code gives me this error: "Zero-length blob
> not permitted".
> 
> @magick_image = Magick::Image.from_blob(@file.read).first
> 
> Where @file is a StringIO object or a File object, depending on the
> size of the uploaded file.
> 
> @file.read.size returns the expected file size (in bytes).
> 
> Any ideas?

Well, it works for me. Here's my attempt to reproduce the problem.

require 'RMagick'
require 'stringio'

file = File.open('Flower_Hat.jpg')
img = Magick::Image.from_blob(file.read).first
p img

blob = IO.read('Flower_Hat.jpg')
sio = StringIO.new(blob)
img = Magick::Image.from_blob(sio.read).first
p img


The output is:
tim: ~> ruby  test.rb
 JPEG 200x250 DirectClass 8-bit 9kb
 JPEG 200x250 DirectClass 8-bit 9kb


-- 
Tim Hunter