title: Split option to have the variable at the beginning instead on the end?
body: <p>I have a file of 47 million lines, I want to split this into files of 2 million lines, but the end of the filename has to be the same.</p>
  
  <pre><code>split -l 2000000 test_F5.csfasta splitted_test_F5.csfasta
  </code></pre>
  
  <p>This split command gives me these files:
  test_F5.csfstaaa, 
  test_F5.csfstaab, etc</p>
  
  <p>And I want these files:
  aatest_F5.csfasta, 
  abtest_F5.csfasta, etc</p>
  
  <p>Is there mayba a function in split to do this, or another way to fix this problem?</p>