# Best Way of Extracting Key Value from File **URL:** \ **Category:** Rails\ **Created:** [June 18, 2008, 3:14pm UTC](https://www.ruby-forum.com/t/best-way-of-extracting-key-value-from-file/140786 "2008-06-18T15:14:43Z")\ **Posts on this page:** 4\ **Page:** 1
**Author:** ![ror\_arch](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/r/e19adc/32.png) [@ror\_arch](https://www.ruby-forum.com/u/ror_arch)\ **Post date:** [June 18, 2008, 3:14pm UTC](https://www.ruby-forum.com/t/best-way-of-extracting-key-value-from-file/140786/1 "2008-06-18T15:14:43Z")
What is the best way of extracting a key value pair from a file. For example I have an email text file which goes like so : – Return-Path: [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) Delivered-To: removed\_email\_address@domain.invalid Date: Sat, 3 May 2008 18:25:13 -0400 From: “Athar Shiraz Siddiqui” [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) To: removed\_email\_address@domain.invalid Subject: Testing your email checking capabilities MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Content-Disposition: inline ## testing … Now I would like to extract the usual From: and To: values from this text file. YAML seems ideal for this but the only problem is that YAML gives the following error : ArgumentError (syntax error on line 23, col -1: `To: removed\_email\_address@domain.invalid Subject: Testing your email checking capabilities MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Content-Disposition: inline testing … ‘): c:/ruby/lib/ruby/1.8/yaml.rb:133:in `load' c:/ruby/lib/ruby/1.8/yaml.rb:133:in `load’ /app/controllers/messages\_controller.rb:66:in `parseMessage’; So this is definitely a problem and I can’t use YAML. I tried regexps but I am new to them and I can only extract the entire line like so : result = /^From:.\*$/.match(@emailcontent) # where @email content is the text of the email Regexp result matchdata object gets the entire From : “…” \<\> line including the from. I would like the value of “From:” (NOT including From: meaning I would like the email address that is after the colon). What do I use here ? In java we could do string.indexof and substring etc. Is there something comparable? I am going through the api right now and thinking of a way of removing the “from:” key from the returned line ; delete won’t work because it deletes all characters in intersection! so that wont extract the value of “From:” . I am trying gsub(“From:”, “”) as a work around for now. but any less clunking solutions would be sweet. ---
**Author:** ![ror\_arch](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/r/e19adc/32.png) [@ror\_arch](https://www.ruby-forum.com/u/ror_arch)\ **Post date:** [June 18, 2008, 3:17pm UTC](https://www.ruby-forum.com/t/best-way-of-extracting-key-value-from-file/140786/2 "2008-06-18T15:17:30Z")
If you just need to read e-mails, you can do that without bothering with saving them to a file. The to/from fields will be easily accessible then. I ended up using an ActionMailer and the plugin linked to here: [http://siannopollo.blogspot.com/2008/02/mail-fetcher-fetch-email-from-ruby-and.html](http://siannopollo.blogspot.com/2008/02/mail-fetcher-fetch-email-from-ruby-and.html) You’ll need to modify that plugin a bit, however. If its what you’re looking for, let me know when you get stuck with it, and I’ll try and help out. ---
**Author:** ![ror\_arch](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/r/e19adc/32.png) [@ror\_arch](https://www.ruby-forum.com/u/ror_arch)\ **Post date:** [June 18, 2008, 3:24pm UTC](https://www.ruby-forum.com/t/best-way-of-extracting-key-value-from-file/140786/3 "2008-06-18T15:24:17Z")
Dan \_\_ wrote: > If you just need to read e-mails, you can do that without bothering with > saving them to a file. The to/from fields will be easily accessible > then. > > I ended up using an ActionMailer and the plugin linked to here: > [http://siannopollo.blogspot.com/2008/02/mail-fetcher-fetch-email-from-ruby-and.html](http://siannopollo.blogspot.com/2008/02/mail-fetcher-fetch-email-from-ruby-and.html) > > You’ll need to modify that plugin a bit, however. If its what you’re > looking for, let me know when you get stuck with it, and I’ll try and > help out. Precisely I just need to read emails from the inboxes folder/directory of the James Mail server. ([http://james.apache.org](http://james.apache.org)) This however looks promising. It is an SMTP server though (not pop) ---
**Author:** ![ror\_arch](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/r/e19adc/32.png) [@ror\_arch](https://www.ruby-forum.com/u/ror_arch)\ **Post date:** [June 18, 2008, 3:30pm UTC](https://www.ruby-forum.com/t/best-way-of-extracting-key-value-from-file/140786/4 "2008-06-18T15:30:07Z")
Unfortunately, I don’t know how to read emails from an SMTP server ☹ The plugin I sent only works with POP and IMAP. I faced this problem a little while ago (although I was using a POP server), and I still have bookmarks from when I was searching. Perhaps one of them will help you? [http://wiki.rubyonrails.org/rails/pages/HowToReceiveEmailsWithActionMailer](http://wiki.rubyonrails.org/rails/pages/HowToReceiveEmailsWithActionMailer) [http://blog.craigambrose.com/past/2008/2/9/respond\_toemail\_or\_how\_to\_handle/](http://blog.craigambrose.com/past/2008/2/9/respond_toemail_or_how_to_handle/) [http://offtheline.net/2008/2/14/receiving-email-with-rails](http://offtheline.net/2008/2/14/receiving-email-with-rails) Most of the examples use SMTP, but not the James Mail server you’re using. So I think you could use the basic idea, but you’d have to figure out the specific configurations yourself.