convert a buffer with is own charset
var strbuf = require('strbuf');
fs.readFile('/path/to/file', function(error, data){
if(error){
throw error;
}
console.log(strbuf(data));
});
or simply
// "中文abc";
var big5Buffer = new Buffer([0xa4,0xa4,0xa4,0xe5,0x61,0x62,0x63]),
console.log(strbuf(big5Buffer));
==> 中文abc