Nodejs readline giving some error - node.js

Question

I want to read a file line by line and based on the data in each line i have to categorise the data.
var rd = readline.createInterface({
input: fs.createReadStream('/home/user/Desktop/text.txt'),
output: process.stdout,
console: false
});
When this line is executed the file is read and printed in the terminal.
But when I try to read the file line by line using readline I am getting error.
rd.on('line', (input) => {
console.log(input);
});
I am getting the following error.
`Interface {
_sawReturnAt: 0,
isCompletionEnabled: true,
_sawKeyPress: false,
_previousKey:
{ sequence: '\n',
name: 'enter',
ctrl: false,
meta: false,
shift: false },
domain:
Domain {
domain: null,
_events: { error: [Function: debugDomainError] },
_eventsCount: 1,
_maxListeners: undefined,
members: [] },
_events: { line: [ [Function], [Function], [Function] ] },
_eventsCount: 1,
_maxListeners: undefined,
output:
WriteStream {
connecting: false,
_hadError: false,
_handle:
TTY {
bytesRead: 0,
_externalStream: {},
fd: 9,
writeQueueSize: 0,
owner: [Circular],
onread: [Function: onread] },
_parent: null,
_host: null,
_readableState:
ReadableState {
objectMode: false,
highWaterMark: 16384,
buffer: [Object],
length: 0,
pipes: null,
pipesCount: 0,
flowing: null,
ended: false,
endEmitted: false,
reading: false,
sync: true,
needReadable: false,
emittedReadable: false,
readableListening: false,
resumeScheduled: false,
defaultEncoding: 'utf8',
ranOut: false,
awaitDrain: 0,
readingMore: false,
decoder: null,
encoding: null },
readable: false,
domain: null,
_events:
{ end: [Object],
finish: [Function: onSocketFinish],
_socketEnd: [Function: onSocketEnd],
resize: [Object] },
_eventsCount: 4,
_maxListeners: undefined,
_writableState:
WritableState {
objectMode: false,
highWaterMark: 16384,
needDrain: false,
ending: false,
ended: false,
finished: false,
decodeStrings: false,
defaultEncoding: 'utf8',
length: 0,
writing: false,
corked: 0,
sync: false,
bufferProcessing: false,
onwrite: [Function: bound onwrite],
writecb: null,
writelen: 0,
bufferedRequest: null,
lastBufferedRequest: null,
pendingcb: 1,
prefinished: false,
errorEmitted: false,
bufferedRequestCount: 0,
corkedRequestsFree: [Object] },
writable: true,
allowHalfOpen: false,
destroyed: false,
_bytesDispatched: 22151,
_sockname: null,
_writev: null,
_pendingData: null,
_pendingEncoding: '',
server: null,
_server: null,
columns: 80,
rows: 24,
_type: 'tty',
fd: 1,
_isStdio: true,
destroySoon: [Function],
destroy: [Function] },
input:
ReadStream {
_readableState:
ReadableState {
objectMode: false,
highWaterMark: 65536,
buffer: [Object],
length: 0,
pipes: null,
pipesCount: 0,
flowing: false,
ended: true,
endEmitted: true,
reading: false,
sync: false,
needReadable: false,
emittedReadable: false,
readableListening: false,
resumeScheduled: false,
defaultEncoding: 'utf8',
ranOut: false,
awaitDrain: 0,
readingMore: false,
decoder: null,
encoding: null },
readable: false,
domain:
Domain {
domain: null,
_events: [Object],
_eventsCount: 1,
_maxListeners: undefined,
members: [] },
_events: { end: [Object], data: [Function: onData] },
_eventsCount: 2,
_maxListeners: undefined,
path: '/home/user/Desktop/text.txt',
fd: null,
flags: 'r',
mode: 438,
start: undefined,
end: undefined,
autoClose: true,
pos: undefined,
bytesRead: 31,
destroyed: true,
closed: true },
historySize: 30,
crlfDelay: 100,
_prompt: '> ',
terminal: true,
line: '',
cursor: 0,
history: [ '1,2,3', '4,8,4,8', '2,2,2,2', '1,2,3,4' ],
historyIndex: -1,
prevRows: 0,
paused: true,
closed: true }`
Please help I am new to this.

Answer 1

Your code looks fine but you are using the Node.js REPL rather than running the code from a file, which is why you're seeing this behaviour.
The Node.js REPL (what you get when you type node in terminal) will store variables. However, when only an identifier is used the value is also returned. What you're seeing isn't an error, but the rd object.
The Node.js REPL is good for testing but, unless you have a specific reason for using it, the best thing to do is create an app.js file, add your code to it and then run node app.js.
If you do need to write multi-line code using REPL, then be sure to type .editor once initialised, so that whitespace, etc. is interpreted correctly.
Also, from the 7.7.2 docs console isn't an option which createInterface is expecting, so that can be removed. In your particular example, you could also remove output: process.stdout, as your logging each line using the line event