Hi, In my upcoming application we are uploading the pdf files. After uploading the pdf file I have to extract the text from pdf and display it to user. can anyone tell me how to extract text from pdf file? Is there any plugin or gem present for this? Thanks, Tushar
I did this using Paperclip and defining a processor for Paperclip as follows:
#lib/paperclip_processors/text.rb module Paperclip # Handles extracting plain text from PDF file attachments class Text < Processor
attr_accessor :whiny
# Creates a Text extract from PDF def make src = @file dst = Tempfile.new([@basename, 'txt'].compact.join(".")) command = <<-end_command "#{ File.expand_path(src.path) }" "#{ File.expand_path(dst.path) }" end_command
begin success = Paperclip.run("/usr/bin/pdftotext -nopgbrk", command.gsub(/\s+/, " ")) Rails.logger.info "Processing #{src.path} to #{dst.path} in the text processor." rescue PaperclipCommandLineError raise PaperclipError, "There was an error processing the text for #{@basename}" if @whiny end dst end end end
#app/models/document.rb has_attached_file :pdf,:styles => { :text => { :fake => 'variable' } }, :processors => [:text] after_post_process :extract_text
private def extract_text file = File.open("#{pdf.queued_for_write[:text].path}","r") plain_text = "" while (line = file.gets) plain_text << Iconv.conv('ASCII//IGNORE', 'UTF8', line) end self.plain_text = plain_text #text column to hold the extracted text for searching end
I had to find and install the creaky-old pdftotext library on my server (happily, there was an apt-get bundle for it) and configure the path correctly. When Paperclip accepts a PDF upload, it creates a text extraction of that file and saves it in system/pdfs/:id/text/filename.pdf. Note that while it has a .pdf extension, the file itself is actually just the plain text extracted from the original pdf. After quite a lot of googling and begging my local Ruby group, I got the recipe for ripping open that text file and reading it into a variable to store on the record. The text you get out of pdftotext will vary wildly in quality and comprehensiveness, but since all I needed was a way to get a simple search system fed, it works fine for my needs. I never show this text to anyone, just use it as the "keywords" for search. You may want/need to present an editing field for the administrator to clean up these extracted texts.
Walter
pdftk, pdfbox (java), pdfkit
Garrett Lancaster
I wrote a plugin that requires attachment_fu and some unixy utilities behind the scenes for this several years back:
https://github.com/kete/convert_attachment_to
It works reliably in Rails 2.x apps. I haven’t tried it with Rails 3 yet. You could fork it and update (make it work with PaperClip or Rails 3) it you like or just have a gander for example code.
Cheers,
Walter
I don't see how these relate to the question -- they are apparently designed to generate PDFs rather than to extract text from existing PDF documents. Can you point to an example where these libraries can be used in that fashion? I'd love to use something more professionally developed than my own system.
Walter
PDFBox is the library I’m using on a current project: There is a link to “Extract Text” under Command Line Utilities. There is also a section called “Text Extraction” under Tutorials. There is a ruby command line utility that wraps PDFBox called Docsplit: that might be worth looking into. For pdftk: Hope this helps, Garrett Lancaster
