Answers.Body: <p>I'm surprised nobody has responded in six months, sorry I haven't been here :-(</p>
  
  <p>I do this all the time.  </p>
  
  <p>You want to convert everything that has <code>formats:"=PDF"</code> and doesn't have <code>formats:"=MOBI"</code>.  You can just put those conditions in the search box, or in the tag browser:</p>
  
  <ul>
  <li>Select the PDF format (which will place a big <strong>+</strong> beside it), then</li>
  <li>ctrl-select the MOBI format <strong>twice</strong>, instead of a <strong>+</strong> there'll be a <strong>-</strong></li>
  </ul>
  
  <p>You'll see the following selection string in the search box: <code>not formats:"=MOBI" or formats:"=PDF"</code>. Now you have all the books that are <em>either</em> not MOBI or <em>are</em> PDF.  That's not nearly what you want, but now just change the <code>or</code> to <code>and</code> (or delete it—no conjunction is the same as using <code>and</code>) in the search box and you have all of the PDFs that <em>don't</em> also have a MOBI.</p>
  
Answers.ContentLicense: CC BY-SA 3.0
Answers.CreationDate: 2017-01-14T16:36:37.193Z
Answers.LastActivityDate: 2017-01-14T16:36:37.193Z
Answers.UserDisplayName: Auspex
Body: <p>I'm using calibre to convert my books from pdf to mobi. My issue is that I have hundreds of books that are already in the mobi format and I'm looking only to convert the books that aren't already in the mobi format. </p>
  
  <p>When I try to convert all of my books it converts the pdf books into mobi even if they are already in mobi. To convert my book collection is going to take many hours, and I'm wondering if there is a way to mass convert books that aren't already in the output format.</p>
  
  <p>Thank you. Will accept any work around that accomplishes this. </p>
  
Comments.ContentLicense: CC BY-SA 3.0
Comments.CreationDate: 2016-07-17T19:23:43.450Z
Comments.Text: Will calibre give me a list of books not in a specific format?
Comments.UserDisplayName: Ravenous
Comments.ContentLicense: CC BY-SA 3.0
Comments.CreationDate: 2016-07-18T04:00:15.723Z
Comments.Text: What operating system are you running calibre on, and how comfortable are you with the command line?  :-)  I might not understand the question correctly, but if you want to convert some of your books (and not all), you might try (1) finding that subset of books in format FOO and then (2) sending the list of those books in FOO format to the calibre command line.  Link to Calibre command line https://manual.calibre-ebook.com/generated/en/cli-index.html  Could you expand your question with a sample of what you want to convert and what you do not want to convert?  Thank you.
Comments.UserDisplayName: StandardEyre
Tags: <calibre>
Title: How to sort on books that aren't in a specific format in calibre
UserDisplayName: Ravenous
ThreadText: # How to sort on books that aren't in a specific format in calibre
  
  (Asked by: username_0 on 2016-07-17)
  
  I'm using calibre to convert my books from pdf to mobi. My issue is that I have hundreds of books that are already in the mobi format and I'm looking only to convert the books that aren't already in the mobi format.
  
  When I try to convert all of my books it converts the pdf books into mobi even if they are already in mobi. To convert my book collection is going to take many hours, and I'm wondering if there is a way to mass convert books that aren't already in the output format.
  
  Thank you. Will accept any work around that accomplishes this.
  
  **Tags:** calibre
  
  > **Comments:**
  > **username_0**: Will calibre give me a list of books not in a specific format?  
  > **username_1**: What operating system are you running calibre on, and how comfortable are you with the command line?  :-)  I might not understand the question correctly, but if you want to convert some of your books (and not all), you might try (1) finding that subset of books in format FOO and then (2) sending the list of those books in FOO format to the calibre command line.  Link to Calibre command line https://manual.calibre-ebook.com/generated/en/cli-index.html  Could you expand your question with a sample of what you want to convert and what you do not want to convert?  Thank you.  
  
  ---
  
  ## 1 answers
  
  ### Answer by username_2 on 2017-01-14. Score: 5
  
  I'm surprised nobody has responded in six months, sorry I haven't been here :-(
  
  I do this all the time.
  
  You want to convert everything that has `formats:"=PDF"` and doesn't have `formats:"=MOBI"`. You can just put those conditions in the search box, or in the tag browser:
  
  * Select the PDF format (which will place a big **+** beside it), then
  * ctrl-select the MOBI format **twice**, instead of a **+** there'll be a **-**
  
  You'll see the following selection string in the search box: `not formats:"=MOBI" or formats:"=PDF"`. Now you have all the books that are *either* not MOBI or *are* PDF. That's not nearly what you want, but now just change the `or` to `and` (or delete it—no conjunction is the same as using `and`) in the search box and you have all of the PDFs that *don't* also have a MOBI.
  
  
  ---
  
  