• Is there a bug in Socket.data_waiting ?

    From nelgin@VERT/EOTLBBS to Digital man on Wed Feb 21 11:30:23 2024
    I'm trying to fetch the login screen for a MUD and having some issues.

    If I use telnet aardmud.org 4000 then it connects and.
    nc aardmud.org 4000 produces some junk characters and then displays the login screen. I guess they're some sort of terminal detection or negotiation. tcpdump output doesn't look like telnet negotiation.

    Now with js I'm trying this:

    var sock = new Socket(SOCK_STREAM);
    try { sock.connect('aardmud.org',4000,5) }
    catch(e) {
    writeln(e);
    exit();
    }
    sock.is_connected show true. So let me check if there's some data waiting for me.

    sock.data_waiting shows false
    sock.ndata shows 0
    sock.poll(0,true) shows the socket is set for reading.

    now if I use sock.recvline I get a line of data. So if there's data waiting, why wouldn't data_waiting tell me?

    Maybe I am misunderstanding how it all works.

    What would be the best way of getting the data upto the point where I am asked to login?

    ---
    Synchronet End Of The Line BBS - endofthelinebbs.com
  • From Digital Man@VERT to nelgin on Wed Feb 21 11:25:52 2024
    Re: Is there a bug in Socket.data_waiting ?
    By: nelgin to Digital man on Wed Feb 21 2024 11:30 am

    I'm trying to fetch the login screen for a MUD and having some issues.

    If I use telnet aardmud.org 4000 then it connects and.
    nc aardmud.org 4000 produces some junk characters and then displays the login screen. I guess they're some sort of terminal detection or negotiation. tcpdump output doesn't look like telnet negotiation.

    Now with js I'm trying this:

    var sock = new Socket(SOCK_STREAM);
    try { sock.connect('aardmud.org',4000,5) }
    catch(e) {
    writeln(e);
    exit();
    }
    sock.is_connected show true. So let me check if there's some data waiting for me.

    sock.data_waiting shows false
    sock.ndata shows 0
    sock.poll(0,true) shows the socket is set for reading.

    now if I use sock.recvline I get a line of data. So if there's data waiting, why wouldn't data_waiting tell me?

    I would expect data_waiting to be true.


    Maybe I am misunderstanding how it all works.

    What would be the best way of getting the data upto the point where I am asked to login?

    It might be best to figure out what that initial handshake is and deal with that first.
    --
    digital man (rob)

    Synchronet "Real Fact" #58:
    The last version of Synchronet to run on MS-DOS and OS/2 was v2.30c (1999) Norco, CA WX: 61.7F, 78.0% humidity, 0 mph SSW wind, 0.75 inches rain/24hrs ---
    Synchronet Vertrauen Home of Synchronet [vert/cvs/bbs].synchro.net
  • From nelgin@VERT/EOTLBBS to Digital Man on Wed Feb 21 13:52:22 2024
    Re: Is there a bug in Socket.data_waiting ?
    By: Digital Man to nelgin on Wed Feb 21 2024 11:25:52

    now if I use sock.recvline I get a line of data. So if there's data waiting, why wouldn't data_waiting tell me?

    I would expect data_waiting to be true.

    Definately false.
    $ cat socktest.js

    'use strict';
    load("sbbsdefs.js");
    load('sockdefs.js');


    var sock = new Socket(SOCK_STREAM);
    try { sock.connect('aardmud.org',4000,5) }
    catch(e) {
    writeln(e);
    exit();
    }

    writeln("data? " + sock.data_waiting);
    sock.close();
    bbs@bbs:/sbbs/xtrn/mudlist/scripts$ jsexec -n socktest.js
    data? false


    It might be best to figure out what that initial handshake is and deal with that first.

    I did find the telnet negotiation strings in the end, they were a bit buried, so that is sorted.

    ---
    Synchronet End Of The Line BBS - endofthelinebbs.com
  • From Digital Man@VERT to nelgin on Wed Feb 21 20:24:51 2024
    Re: Is there a bug in Socket.data_waiting ?
    By: nelgin to Digital Man on Wed Feb 21 2024 01:52 pm

    Re: Is there a bug in Socket.data_waiting ?
    By: Digital Man to nelgin on Wed Feb 21 2024 11:25:52

    now if I use sock.recvline I get a line of data. So if there's data waiting, why wouldn't data_waiting tell me?

    I would expect data_waiting to be true.

    Definately false.
    $ cat socktest.js

    'use strict';
    load("sbbsdefs.js");
    load('sockdefs.js');


    var sock = new Socket(SOCK_STREAM);
    try { sock.connect('aardmud.org',4000,5) }
    catch(e) {
    writeln(e);
    exit();
    }

    Socket.connect() doesn't throw an exception upon failure (it just retuns false on failure) - so why the try/catch here?

    writeln("data? " + sock.data_waiting);
    sock.close();
    bbs@bbs:/sbbs/xtrn/mudlist/scripts$ jsexec -n socktest.js
    data? false

    I wrote a quick little test here and it shows Socket.data_waiting working as expected:

    var sock = new Socket();
    if(!sock.connect("vert.synchro.net", 23)) {
    alert("connect failure " + sock.error_str);
    exit(1);
    }
    while(sock.is_connected) {
    if(sock.data_waiting)
    print(JSON.stringify(sock, null, 4));
    }
    --
    digital man (rob)

    Sling Blade quote #10:
    Morris: I stand on the hill, not for thrill, but for the breath of a fresh kill Norco, CA WX: 53.7F, 87.0% humidity, 1 mph NNW wind, 0.19 inches rain/24hrs ---
    Synchronet Vertrauen Home of Synchronet [vert/cvs/bbs].synchro.net
  • From nelgin@VERT/EOTLBBS to Digital Man on Thu Feb 22 00:42:15 2024
    Re: Is there a bug in Socket.data_waiting ?
    By: Digital Man to nelgin on Wed Feb 21 2024 20:24:51

    'use strict';
    load("sbbsdefs.js");
    load('sockdefs.js');

    var sock = new Socket();

    if(!sock.connect('vert.synchro.net',23)) {
    writeln('Connect failure ' + sock.error_str);
    exit(1);
    }

    writeln("ic: " + sock.is_connected);
    print(JSON.stringify(sock, null, 4));

    So, if I go with this:

    ic: true
    "error_str": "Success",
    "is_writeable": true,
    "is_writable": true,
    "data_waiting": false,
    "nread": 0,

    Shouldn't matter if I'm not in a loop right? When I connect the a socket there's data waiting for me as evidenced by netcat.

    $ nc vert.synchro.net 23

    Synchronet BBS for Win32 Version 3.20
    Telnet connection from: 192.138.210.158
    Resolving hostname...
    '
    _ _
    Synchronet BBS for Win32 Version 3.20 Copyright 2022 Rob Swindell ^[[?6c^[[49;98R^[[49;1R^C

    INterestingly, it seems vert does telnet negotiation after already sending some text.

    ---
    Synchronet End Of The Line BBS - endofthelinebbs.com
  • From Digital Man@VERT to nelgin on Wed Feb 21 23:00:45 2024
    Re: Is there a bug in Socket.data_waiting ?
    By: nelgin to Digital Man on Thu Feb 22 2024 12:42 am

    Re: Is there a bug in Socket.data_waiting ?
    By: Digital Man to nelgin on Wed Feb 21 2024 20:24:51

    'use strict';
    load("sbbsdefs.js");
    load('sockdefs.js');

    var sock = new Socket();

    if(!sock.connect('vert.synchro.net',23)) {
    writeln('Connect failure ' + sock.error_str);
    exit(1);
    }

    writeln("ic: " + sock.is_connected);
    print(JSON.stringify(sock, null, 4));

    So, if I go with this:

    ic: true
    "error_str": "Success",
    "is_writeable": true,
    "is_writable": true,
    "data_waiting": false,
    "nread": 0,

    Shouldn't matter if I'm not in a loop right?

    Yes, it matters. The first time (or several) through the loop, there's not going to be any data waiting.

    When I connect the a socket
    there's data waiting for me as evidenced by netcat.

    $ nc vert.synchro.net 23

    Synchronet BBS for Win32 Version 3.20
    Telnet connection from: 192.138.210.158
    Resolving hostname...
    '
    _
    _
    Synchronet BBS for Win32 Version 3.20 Copyright 2022 Rob Swindell ^[[?6c^[[49;98R^[[49;1R^C

    netcat is polling for received data (in a loop, like the example I pasted). That data is not just immediately available upon connection.

    INterestingly, it seems vert does telnet negotiation after already sending some text.

    Yup. Telnet commands can be sent at any time.
    --
    digital man (rob)

    This Is Spinal Tap quote #38:
    Artie Fufkin: I'm not asking, I'm telling with this. Kick my ass.
    Norco, CA WX: 51.2F, 91.0% humidity, 0 mph ESE wind, 0.16 inches rain/24hrs ---
    Synchronet Vertrauen Home of Synchronet [vert/cvs/bbs].synchro.net
  • From Digital Man@VERT to nelgin on Wed Feb 21 23:51:05 2024
    Re: Is there a bug in Socket.data_waiting ?
    By: nelgin to Digital man on Wed Feb 21 2024 11:30 am

    I'm trying to fetch the login screen for a MUD and having some issues.

    If I use telnet aardmud.org 4000 then it connects and.
    nc aardmud.org 4000 produces some junk characters and then displays the login screen. I guess they're some sort of terminal detection or negotiation. tcpdump output doesn't look like telnet negotiation.

    Now with js I'm trying this:

    var sock = new Socket(SOCK_STREAM);
    try { sock.connect('aardmud.org',4000,5) }
    catch(e) {
    writeln(e);
    exit();
    }
    sock.is_connected show true. So let me check if there's some data waiting for me.

    sock.data_waiting shows false
    sock.ndata shows 0

    You're not going to have data waiting to read *immediately* after a connect.

    sock.poll(0,true) shows the socket is set for reading.

    now if I use sock.recvline I get a line of data. So if there's data waiting, why wouldn't data_waiting tell me?

    Socket.recvline() waits for data (an entire "line" of it, in fact). That's why it has a timeout parameter (that defaults to 30 seconds).
    --
    digital man (rob)

    Synchronet/BBS Terminology Definition #19:
    DCD = Data Carrier Detect
    Norco, CA WX: 50.7F, 91.0% humidity, 0 mph E wind, 0.16 inches rain/24hrs
    ---
    Synchronet Vertrauen Home of Synchronet [vert/cvs/bbs].synchro.net