code: function parseInstallerLog(filepath, searchstring, encoding, callback) {
          var line = "";
          var searchFn = function searchFn(str) {
              var arr = str.split('\n'),
                  lineNum,
                  pos;
              for (lineNum = arr.length - 1; lineNum >= 0; lineNum--) {
                  var searchStrNum;
                  for (searchStrNum = 0; searchStrNum < searchstring.length; searchStrNum++) {
                      pos = arr[lineNum].search(searchstring[searchStrNum]);
                      if (pos !== -1) {
                          line = arr[lineNum];
                          break;
                      }
                  }
                  if (pos !== -1) {
                      break;
                  }
              }
              callback(line);
          };
  
          fs.readFile(filepath, {"encoding": encoding})
              .then(function (str) {
                  return searchFn(str);
              }).catch(function () {
                  callback("");
              });
      }
docs: Parse the Installer log and search for a error strings
  one it finds the line which has any of error String
  it return that line and exit