anhui

fs.createReadStream('readable.txt')
    .pipe(anhui(function(chunk){
        return chunk.toString().toUpperCase();
    }))
    .pipe(fs.createWriteStream('writable.txt'));

var myanhui = anhui(function(chunk){
    if (typeof chunk == "string"){
        return chunk.toString().toUpperCase();
    } else if (typeof chunk == "object"){
        var obj = chunk;
        if (obj.hasOwnProperty("zhc")) {
            obj.zhc = "321"
        } 
        return obj;
    }
},{objectMode:true});
 
// try it out
myanhui.on("data",function(chunk){
    console.log(chunk);
});
 
myanhui.write({zhc:"123"}); // input line 1
myanhui.write('another line\n');  // input line 2
myanhui.end();  // finish