title: ShellCommandActivity in AWS Data Pipeline
body: <p>I am transferring Dynamo DB data to S3 using Data Pipeline. In the S3 bucket I get the backup but it is split into multiple files. To get the data in a single file I used a Shell Command Activity which runs the following command:</p>
  
  <pre class="lang-none prettyprint-override"><code>aws s3 cat #{myOutputS3Loc}/#{format(@scheduledStartTime,'YYYY-MM-dd')}/* &gt; #{myRenamedFile}
  </code></pre>
  
  <p>This should concatenate all the files present in the S3 folder to a single file named <code>#{myRenamedFile}</code>. But I get the following error in data pipeline:</p>
  
  <pre class="lang-none prettyprint-override"><code>usage: aws [options] &lt;command&gt; &lt;subcommand&gt; [&lt;subcommand&gt; ...] [parameters] To see help text, you can run: aws help aws &lt;command&gt; help aws &lt;command&gt; &lt;subcommand&gt; help aws: error: argument subcommand: Invalid choice, valid choices are: ls | website cp | mv rm | sync mb | rb
  </code></pre>
  
  <p>Does this mean <code>cat</code> is not supported in Shell Command Activity or is there something wrong here? Is there any other method to combine the different files to a single file in S3 itself?</p>