fs/close

54.js

var fs = require('fs');

function openAndWriteToSystemLog(writeBuffer, callback) {
  fs.open('/var/log/system.log', 'a', function opened(err, fd) {
    if (err) { return callback(err); }
    function notifyError(err) {
      fs.close(fd, function() {
        callback(err);
      });
    }
    var bufferOffset = 0,
        bufferLength = writeBuffer.length, filePosition = null;
    fs.write( fd, writeBuffer, bufferOffset, bufferLength, filePosition, function wrote(err, written) {
      if (err) { return notifyError(err); }
      fs.close(fd, function() {
        callback(err);
      });
    });
  });

openAndWriteToSystemLog(
new Buffer('writing this string'),
function done(err) {
if (err) {
console.log("error while opening and writing:", err.message);
return;
}
console.log('All done with no errors');
}
);