title: create executing a command with a sequence of files as the input, comma separated
body: <p>Forgive me, this may be a simple operation, but I am coming from object oriented programming languages, and this is not very intuitive to do in unix/bash/terminal.</p>
  
  <p>Say I want to execute a command a list of files, <code>file1,file2,file3</code> so the command would read</p>
  
  <pre><code>cmd -i file1,file2,file3
  </code></pre>
  
  <p>Now, say I have 1000 files like this. I'd like to just run it through all of the files. However. If I merely enter</p>
  
  <pre><code>cmd -i file{1..1000}
  </code></pre>
  
  <p>I receive an error. This is because <code>file{1..1000}</code> returns a list that looks like</p>
  
  <pre><code>file1 file2 file3 file4....
  </code></pre>
  
  <p>And I need it to return
      file1,file2,file3,file4,....</p>