title: Bash - substring extraction
body: <p>I have a variable <code>"$var"</code> of type: <code>"YYYYMMDD_charcharchar...charchar.ext"</code>
  After the first "_" there can be other one (1 or more) or none.</p>
  
  <p>I have to truncate the first part <code>"YYYYMMDD_"</code> and leave in a <code>$new_var</code> <code>"charcharchar...charchar.ext"</code>.</p>
  
  <p>I can't use "bash expansions" like
  <code>${string:position}</code>
  because I'm into emulated environment (Cygwin)</p>
  
  <p>thanks.</p>