What does ^b in csh do?

I'm looking at a shell inside tmux, accidentally caused a ^b to be sent and it isn't responding.

It's a tmux escape code, not csh.

^b c can create a new window, ^b w can switch windows

Yes, but ^b^b will cause it to send a ^b and the shell's state seems to now be unknown.

Ah, perhaps tmux is in some sort of command-mode.

so the shell received a ^B?

Seems tmux had gotten into some sort of command mode, simply needed a 'q' to be talking to the shell again.

Okay finally archived any history from that shell.

rwp: Thank you. Yeah, that doesn't sound bad.

nesting tmux is illegal in many states

citation?

it's a joke haha

punchline shoulda been a funny citation

comedians never give up

dang you're right

you nest tmux?

i nested 3 instances of emacs inside emacs

I used emacs shell to ssh into a server and use emacs there

then i continued to use ssh from there to another server

i nest tmux

Now I need to find help with Sendmail (guess how long this installation has been around).

geometry: What's your Sendmail doing?

Rather a lot for this site. :-/

In this case a message was rejected by a rule and I'm not too familiar with Sendmail rules.

"ruleset=check_relay"

"reject=550 5.7.1 Access denied", though that should nominally be incoming handled by the local system.

geometry: Safest bet is to ignore .cf and manage your config with .mc.

Would be safe, accept this is an existing installation and I'm not ready to make major changes yet.

^accept^except

geometry: Well. If it's failing in various ways, getting it under control is critical, and having a maintainable config is part of that. It'd be worth understanding what the expected behaviour is.

I suspect it may be a maintainable config, but it was written by someone who had been working on it for decades.

geometry: Your error sounds like it's an outdated RBL or something, possibly, and that could have some pretty bad effects on delivery depending on how you react to the inability to check.

geometry: Well. They should have been using .mc. That was the best practise when I started using Sendmail in the 90s.

If they're doing funny things in .cf, those should have been well-documented. It's really just about unheard-of to have anything that would require any complexity in .cf.

geometry: So you can do things like, configure a sane .mc, generate a .cf, and see how it differs from what you've got.

is the format of .cf directly docuented?

They may be derived from the .mc files, but I'm less than 100% certain of that.

geometry: Find all the .mc files you can, generate .cf's from them, and see what matches or what's closest.

And as LXGHTNXNG notes, see if they properly commented the .cf in the event that they were writing .cf directly.

Ah, I think I found the issue.

Also, if it's a legacy system and no one's been maintaining it, look at mtimes on the various files and you might match up .mc and .cf that way.

Someone had been maintaining it, but I think they had gotten over their head.

Easy to do.

They were resorting to desparation tactics to try to cut down on spam and looks like they added something incorrect to the access list.

Hmm, seems the RCS files are out of date. :-(

geometry: Look at dnsbl here: sendmail.org/~ca/email/doc8.12/cf/m4/features.html

Should be trivial to add.

The last time I ran Sendmail myself, I was using it with UUCP. But I've had to support it for other folks much more recently.

The real problem is nothing is the spammers are still trying despite all efforts to fight them. :-(

^is nothing^

Educating users still isn't crushing their margins sufficiently to make them stop.

I haven't decided advertising is inherently evil, but I've started to wonder...

geometry: Beware, a whole new worldview awaits you.