On Sun, 2006-06-25 at 14:20 -0500, Larry Vaden wrote:
> Hello,
>
> Is anyone else having problems with the ssh session output stalling
> when ssh'd to another system and the command is running via sudo and a
> pager is being used (e.g., more)?
>
> Too highly reproducible :( to date, all known occurrences have
> involved Centos 4.3 servers; makes no difference whether client is
> RHEL WS 4.3, Centos 4.3 or FC 5 or WinDoze. Makes no difference if
> terminal emulator is Gnome's stock issue or Konsole or Putty. Not
> sure about SecureCRT.
If sudo is removed from the mix, does it still happen?
>
> Sometimes one can break loose the logjam; if so:
> . terminal prompts are stacked left to right vs. vertically
> . keyboard input is not echo'd
These two tell us that end-of-line and other terminal settings (usually
NL on *IX systems, but I don't know about ssh) are getting lost before
the pager is seeing them. Possibly doing stty against the pseudo-terms
involved will give a clue?
> . in this event, terminal clear/reset doesn't
> end if so.
>
> Any thoughts?
Generally, having a pager involved when there are interactive prompts
("terminal prompts are stacked...") is a bad idea. Commands often issue
prompts with no EOL so that you see on one line something like
Enter reply [Y/N/Q] -
and the cursor is after the dash. The pager usually works on *lines* not
*characters*, although some used to have timeouts that could be applied
to force output flushing (don't know if this applies anymore).
Wish I had more to offer than just a couple Qs that might get you going.
>
> rgds/ldv
>
> [vaden at mx1 ~]$ ps auxw | grep -i pts/0
> vaden 2475 0.0 0.1 37444 3064 ? S 04:53 0:00 sshd: vaden at pts/0
> vaden 2476 0.0 0.0 53964 1480 pts/0 Ss 04:53 0:00 -bash
> root 2511 0.0 0.0 71284 1312 pts/0 S 04:53 0:00 su -
> root 2512 0.0 0.0 53968 1492 pts/0 S 04:53 0:00 -bash
> root 3426 0.0 0.0 2376 288 pts/0 S+ 13:57 0:00 sesh
> /bin/grep -i unknown /var/log/maillog
> root 3427 0.1 0.0 51128 784 pts/0 S+ 13:57 0:00
> /bin/grep -i unknown /var/log/maillog
> vaden 3434 0.0 0.0 51072 540 pts/1 R+ 13:58 0:00 grep -i pts/0
> <snip sig stuff>
--
Bill
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