Opening 5250 terminals seems to open PASE terminal instead

[dlanz]

Running which tn5250 returns:
/QOpenSys/pkgs/bin/tn5250

Running tn5250 -version returns:
tn5250 0.17.6

Using the same profile, I'm able to connect with Code for IBM i and open a PASE terminal without issue. However, it seems when attempting to open a 5250 session, a "green screen" flashes momentarily before switching to a PASE terminal. In the resulting PASE terminal, it contains TERM=xterm /QOpenSys/pkgs/bin/tn5250 env.DEVNAME=PCS2561_4 localhost in the session history.

The flash is quick, but long enough to be certain it only occurs when trying to open a 5250 terminal. Opening PASE directly does not produce the behavior.

The system I'm connecting to requires a device description to exist before connecting. I have it configured to prompt for the device name, and I enter a name which is successful when using ACS.

I have tried disconnecting, then using "Connect and Reload Server Settings." as mentioned in the docs, but it doesn't seem to make a difference.

Anyone have any ideas? It would be amazing if I didn't have to switch back and forth between ACS's 5250 and VSCode!

[worksofliam]

Interesting. If you run the command yourself from a PASE shell, do you get the same result?

TERM=xterm /QOpenSys/pkgs/bin/tn5250   env.DEVNAME=PCS2561_4 localhost

[dlanz]

Sorry, I just realized you added localhost to the end of that.
Sorry, I just realized I omitted the localhost in the prior post.

Yes, I get the same behavior of the flash when I run:
TERM=xterm /QOpenSys/pkgs/bin/tn5250 env.DEVNAME=PCS2561_4 localhost

[worksofliam]

@dlanz Looking at the tn5250 man page, I see you're already passing in DEVNAME - I assume device name and description (as you wrote in the original post) are the same?

https://linux.die.net/man/5/tn5250rc

[dlanz]

I'm pretty sure. This is what I get after running:

WRKDEVD DEVD(PCS2561_4)

I tried running TERM=xterm /QOpenSys/pkgs/bin/tn5250 env.DEVNAME=PCS2561_4 localhost in an SSH Tunnel outside of VSCode and get the same exact behavior.

So I doubt this is a Code for IBM i specific issue, but I'm a step closer now. I'll try to read up on TN5250 a bit more to try and figure out what's going on. Thank you for the help for getting this far though.

[worksofliam]

@chrjorgensen is this something you might know about?

[chrjorgensen]

@dlanz @worksofliam I do not get the same behavior on my systems... 😞

You could try tracing the tn5250 by adding the option trace=<tracefile> - it may give you a hint about what's causing the error in tn5250.

[dlanz]

Figured I would just update:

I'm not familiar with tn5250 traces, but this is what I'm getting in the trace file and from what I can tell I'm not seeing any errors.

Non-Blocking
tn5250_dbuffer_clear_table() entered.
tn5250_char_map_new: map = "37"
Found string for cap '@8': '^[OM'.
Found string for cap 'cr': '^M'.
Found string for cap 'kB': '^[[Z'.
Found string for cap 'k1': '^[OP'.
Found string for cap 'k2': '^[OQ'.
Found string for cap 'k3': '^[OR'.
Found string for cap 'k4': '^[OS'.
Found string for cap 'k5': '^[[15~'.
Found string for cap 'k6': '^[[17~'.
Found string for cap 'k7': '^[[18~'.
Found string for cap 'k8': '^[[19~'.
Found string for cap 'k9': '^[[20~'.
Found string for cap 'k;': '^[[21~'.
Found string for cap 'F1': '^[[23~'.
Found string for cap 'F2': '^[[24~'.
Found string for cap 'F3': '^[[1;2P'.
Found string for cap 'F4': '^[[1;2Q'.
Found string for cap 'F5': '^[[1;2R'.
Found string for cap 'F6': '^[[1;2S'.
Found string for cap 'F7': '^[[15;2~'.
Found string for cap 'F8': '^[[17;2~'.
Found string for cap 'F9': '^[[18;2~'.
Found string for cap 'FA': '^[[19;2~'.
Found string for cap 'FB': '^[[20;2~'.
Found string for cap 'FC': '^[[21;2~'.
Found string for cap 'FD': '^[[23;2~'.
Found string for cap 'FE': '^[[24;2~'.
Found string for cap 'kl': '^[OD'.
Found string for cap 'kr': '^[OC'.
Found string for cap 'ku': '^[OA'.
Found string for cap 'kd': '^[OB'.
Found string for cap 'kP': '^[[5~'.
Found string for cap 'kN': '^[[6~'.
Found string for cap 'kb': '^H'.
Found string for cap 'kh': '^[OH'.
Found string for cap '@7': '^[OF'.
Found string for cap 'kI': '^[[2~'.
Found string for cap 'kD': '^[[3~'.
Macro: fname=/home/DL/.tn5250macros
HOST, This->status  = 8 0
GotVerb(2):<IAC><DO><NEWENV>
GotVerb(3):<IAC><DO><NEWENV>
HOST, This->status  = 8 0
GotVerb(2):<IAC><DO><TERMTYPE>
GotVerb(3):<IAC><DO><TERMTYPE>
GotSB:<IAC><SB><NEWENV><SEND>
        <USERVAR>IBMRSEED<E3 D5 04 94 1B C8 F8 15>
        <VAR><USERVAR><IAC><SE>
SentSB:<IAC><SB><NEWENV><IS>
        <VAR>DEVNAME
        <USERVAR>PCS2561_4
        <VAR>TERM
        <USERVAR>IBM-3179-2<IAC><SE>
GotSB:<IAC><SB><TERMTYPE><SEND><IAC><SE>
SentSB:<IAC><SB><TERMTYPE><IS>IBM-3179-2<IAC><SE>
HandleReceive: entered.
HOST, This->status  = 8 1
GotVerb(2):<IAC><DO><END_OF_REC>
GotVerb(3):<IAC><DO><END_OF_REC>
HOST, This->status  = 8 1
GotVerb(2):<IAC><WILL><END_OF_REC>
GotVerb(3):<IAC><WILL><END_OF_REC>
HOST, This->status  = 8 1
GotVerb(2):<IAC><DO><BINARY>
GotVerb(3):<IAC><DO><BINARY>
HOST, This->status  = 8 1
GotVerb(2):<IAC><WILL><BINARY>
GotVerb(3):<IAC><WILL><BINARY>
HandleReceive: entered.
GotSB:<IAC><SB><NEWENV><SEND>
        <USERVAR>DEVNAME<IAC><SE>
SentSB:<IAC><SB><NEWENV><IS>
        <VAR>DEVNAME
        <USERVAR>PCS2561_4
        <VAR>TERM
        <USERVAR>IBM-3179-2<IAC><SE>

The "flashing" behavior, I realized it almost looks as if it is successfully connecting, but then immediately disconnecting. I feel like I can briefly make out what I believe to be a 24x80 screen within the session. I'm still trying to read up on configuring tn5250 on the server. I strongly suspect it's a setting on our server, just not sure which one. If I figure it out, I'll update here.

[dlanz]

I stumbled on the issue.

So I knew the device description could only be used by a single session, so I had logged out of the PCS2561_4 session via ACS before attempting any connections with TN5250. However, I only logged out of the system and left the window opened at the sign on screen.

I have no idea why I didn't consider sitting at the sign on screen as an open connection. As far as telnet and the system is concerned, it is still an open connection under the device description.

[chrjorgensen]

@dlanz Yes, a device showing the login screen is an active device and cannot be acquired by another session. You get the same result, if you try to connect to that specific, active device in another ACS 5250 session. So not a TN5250 issue - but it could be nice and report the cause instead of just dropping out! 🥲 Maybe an idea for the TN5250 project?

[dlanz]

@chrjorgensen Yep, certainly just a picnic error (Problem in chair, not in computer 😄).

That's a good idea, I'll take a look on my lunch break and see if I can make a PR on it.