Re: [exim] ACL filtering 3 dashes in host name

> Dislike 'man' in the command line environment. Never tried it yet in X.

I dislike X. The "man" program is just a pretty wrapper around a file
de-compressor and a pager. You could decompress your man page manually and
then use more/less to read the file by hand if you wish. You could even
search for "man regex" online and find online versions of man pages if
that's easier.

> You're kidding me. I can usually independently analyse most things and
> devise an effective solution. Its called tenacity and uses normal brain
> power. Understanding the logic why something does not work as expected
> is relatively simple but can be time-consuming.

Nope, not kidding. Mensa or not, I believe it'll take you a bit of reading
to grasp RE's properly (see below).

> My answer is *- which in my programming experience means ''anything
> including nothing'' followed by a ''dash''. Note the dash is the
> trailing delimiter. No ending dash means no match.

True, "*" can mean anything including nothing - but why are you separating
"-" from not being part of "anything"? That was exactly what I was getting
at, and is a very common oversight when using RE's. It takes some getting
used to, and once you do you'll never think about pattern matching the same
way again.

> I moved servers to Centos in October and quickly discovered Exim's basic
> default configuration worked well as a backup relay. I also discovered
> the Apache / PHP ''bug'' which ignored, when using PHP mail, -f
> Eventually I discovered how to fix that in Exim. The default Exim
> configuration file could definitely benefit from including that keyword
> as a commented-out example.

If you're referring to the fact that trying to use the -f command line
argument to "mail" to allow a program (such as PHP) to forge a sender
address, that's most certainly not a bug. The fact that perhaps it works
with Sendmail doesn't mean that it should work. By "fixing" it (assuming
you mean that now any user of PHP can effectively use any sender address
they wish), you've now made your life of tracing email origins on your
system that much more difficult; this is why the -f command line option is a
"privileged" option, and cannot be used by non-root users. I was in the
same situation years ago, and my solution was to allow people to rewrite the
sender address to whatever the From: header was set to - but in doing so I
also made sure to write a patch for Exim that would allow me to properly log
the true sender of the email so that when mail forms got hacked and sent out
spam, I knew quickly which account to suspend.

> Generally, every computer programme or system should be useable and
> changeable to a varying extent without reading hundreds of manual pages.

I should most certainly hope not. Would you be OK with that statement from
a major bank employee who was making modifications to the configuration of
their systems that handled your accounts? Exim isn't a small, simple
application - it handles email in many different ways which is why its
documentation is so extensive and exhaustive. If we were talking about a
program that outputs the date and time then sure, but Exim is much, much
more than that.

> A good analogy is children mastering the video and DVD etc. without ever
> reading any manual. Adults tend to rely exclusively on manuals but then
> retain doubts. Another good example is children learning a foreign
> language simply by playing with kids in another country. No manuals, no
> formal instruction and they become fluent faster than adults laboriously
> reading books and trying to get everything precisely right before daring
> to say a word.

Not quite - kids can learn how to use a DVD player easily because it is
built in such a way to prevent tinkering to the point of breaking it.
Buttons are clearly labeled so long as you know the proper nomenclature, so
you don't need a manual to figure out a DVD player. I was able to figure
out my wireless phones I got for the house without the manual, though I did
have to refer to them to figure out how to set up call forwarding (as would
anyone else unless they knew how to do it already). Even then, not *all*
kids figure it out... some still put food in to VHS slots :P

Language is entirely different as well - kids pick it up because they are
exposed to it, just as babies understand the people they hear talking the
most (get a French family with a newborn, sit the baby in a room full of
English speaking people and that baby will understand English before they
will French). Adults have already had their brains "trained", so the whole
"teach an old dog new tricks" thing is what causes Adults issues when trying
to learn new stuff. However, this is off-(list-)topic, so I'll leave it at
this.

Eli.