function safeExec(cmd, cb) {
    try {
      utils._exec(cmd, cb);
    } catch (e) {
      cb(e, null);
    }
  }
function safeExec(cmd, cb) {
    try {
      utils._exec(cmd, cb);
    } catch (e) {
      cb(e, null);
    }
  }
function safeExec ( cmd , cb ) { try { utils . _exec ( cmd , cb ) ; } catch ( e ) { cb ( e , null ) ; } }
Node's built in `exec` function sometimes throws outright,
and sometimes has a callback with an error,
depending on the type of error.

This unifies that interface.
Node s built in exec function sometimes throws outright and sometimes has a callback with an error depending on the type of error .