title: grep with a string variable and a regular expression
body: <p>I am trying to match a regular expression whose string part is contained in a variable as in :  </p>
  
  <pre><code>matches=`grep "^"$*"[ ][0-9]\{1,\}" --count phonelist.txt`
  </code></pre>
  
  <p>where the regex would mean "any line in  phonelist.txt which starts with the command line arguments followed by a space and a number with arbitrary many digits". Have tried many things but can't seem to get it.
  Help</p>