title: Change csv file delimiter in unix
body: <p>I have a number of .csv files with tab delimiter and now I want to change the delimiter. 
  When I use the below script it does not change the file. Please help me with the script.</p>
  
  <pre><code>file_mask=$1
  from_delim=$2
  to_delim=$3
  for i in `ls $file_mask*`
  do
  sed -i 's|$from_delim|$to_delim|g' $i
  done
  </code></pre>