[LAU] Problem connecting to LinuxSampler

R. Mattes rm at mh-freiburg.de
Sun Jun 19 10:05:42 UTC 2011

On Sun, 19 Jun 2011 09:46:08 +0200 (CEST), Julien Claassen wrote
> Hello Ken!
>    Yes, it's 8888. :-) But telnet needs to open a pts/something, or 
> LinuxSampler does to accept the telnet connection. I didn't know it, 
> before I found, that it didn't work and I had to look deeper into 
> things. I researched it some more and am still no further. My system 
> at home runs perfectly and does that, this systems normally runs 
> perfectly, but doesn't do it. I can't find the difference, except in 
> the kernels (My home kernel is custom built)

So the problematic system's kernel is _not_ custom build?
What does:

grep -i PTY /boot/config-`uname -r` 

print? (Here we're just checking the kernel's support for pseudo
terminals as well as the support for legacy pseudo terminals).

> and in the very 
> specific fact, that this system runs udev.   Warm regards            

But that's the way devices are handled in "recent" kernels. And not
a bad way, if I might add ...
So, for debugging purposes, can you do:
ssh localhost
on the problematic system. Iff you theoy is correct, this should
not work.
Can you compile and run the following small C program (compile it with:
gcc tty-tester.c -o tty-tester -lutil )

----X file: tty-tester.c X-------------------------------------------

/* Compile with
gcc tty-tester.c -o tty-tester -lutil
#include <stdio.h>
#include <pty.h>
#include <unistd.h>
#include <errno.h>

int main (int argc, char** argvs) {
    int res;
    int master, slave;
    char  termname[256];
    struct termios termp;
    struct winsize winp;

    res = openpty(&master, &slave, termname, &termp, &winp);
    if (res) {
      printf("Could not open pseudo terminal\n");
      return res;
    printf("Got terminal at %s\n", termname);
    while(1) {sleep(1);}

-------X end file: tty-tester.c X---------------------------------

Just run it and see if we get some more meaningfull error message.

 HTH Ralf Mattes

R. Mattes -
Hochschule fuer Musik Freiburg
rm at inm.mh-freiburg.de

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