title: Replace Line Feed with a Space in unix shell script
body: <p>I have a text file containing some records. Each record is splitted in 4 rows (not always 4), like the example:</p>
  
  <pre><code>----
  row1
  row2
  row3
  row4
  ----
  row1
  etc...
  </code></pre>
  
  <p>Each row is ended with the Line Feed character (LF).
  Ok, I need to obtain the record in only one line, replacing the LF character with a Space, like in example:</p>
  
  <pre><code>---- row1 row2 row3 row4
  ---- row1 row2 ...etcetera
  </code></pre>
  
  <p>Any help or suggestion for the solution?
  Thanks in advance.</p>