Article View: comp.mail.misc
Article #704use of % (was: Making smail2.5 understand <user>%<site>@<site>)
From: Dan Heller
Date: Fri, 13 Oct 1989 18:38
Date: Fri, 13 Oct 1989 18:38
80 lines
4653 bytes
4653 bytes
[ I summarize at the end of this letter ]
> From: jwc@unify.UUCP (J. William Claypool)
> In article <126099@sun.Eng.Sun.COM> argv@sun.UUCP (Dan Heller) writes:
> >Awww, come on... don't leave 'em hanging. You should at least summarize..
> >% has lower precedence than @, but is evaluated left to right like @.
> >It's precedence is equal to !.
> ^^^^^
> Seems to me that % should have LOWER precedence than !.
...
> How about:
> addr2!user%addr1
> shouldn't this be routed the same?
Yes, this is routed the same, but we're now speaking hypothetically
because no "working" mailer would put a %-sign an address without it
having an @-sign in it. (see notes about non-working mailers below).
Because your address is equal to the one's I gave earlier, your
argument does not satisfy your claim that % has lower precedence than
the !. Equal precedence means that the address parsing does not alter
due to the precense of the %.
Similarly, and because we're spekaing "hypothetically" now, this
address is equal:
addr2%addr1!user
> >From: toddp@hp-ptp.HP.COM (Todd_Poynor)
> >% has lower precedence than @, but is evaluated left to right like @.
> >It's precedence is equal to !.
> Not quite -- "%" is evaluated right-to-left, as per the example. There
> should only be one "@" in the address, since source routing using
Back to reality now (no hypothetical situations), %-signs should never
be used without the precense of an @-sign. And because there may be only
*ONE* @-sign in an address, the % is sometimes used but should be treated
no differently than !'s aside from the fact that %'s are evaluated from
left to right as opposed to !'s being evalutated right to left.
From time to time, you'll hear someone whine about mixing @'s and !'s.
Well, you can get around them by using the %-sign. This isn't a good
solution, it's just *a* solution (quality of solution here is not being
evaluated).
> >From: pcf@galadriel.bt.co.uk (Pete French)
> >From article <126099@sun.Eng.Sun.COM>, by argv%turnpike@Sun.COM (Dan Heller):
> > the following are "similar" addresses:
> This is not necessarily true in the case of the second one. Another BT site
> I used to work on ran bog-standard V7 mail - and as such would not understand
> @ signs.
Ok, back to hypothetical again... Let me premise this by saying that
the discussion about @-signs and %-signs and all this should be applied
to meachines that run -at least- RFC-822 compiant MTAs. Attempting to
throw a wrench into the discussion by giving a broken mailer as an example
doesn't work. If your machine doesn't understand @-signs, then users
shouldn't be using it. If you're getting mail from remote sites that
are sending you address that have @-sign in it, those sites are definitely
broken.
> PS: If anyone can tell me where to get a copy of a mailer that will translate
> the @ signs properly then let me know would you....
MTA or MUA? Mush (MUA) provides this functionality to a limited degree.
That is, it will never -generate- an address with an @-sign (if you've
compiled with UUCP defined), but it will allow the user to specify an
address with an @-sign. If you reply to mail, it always converts to uucp
format (if configured to do so).
[ summary ]
Look -- it's like this, plain and simple...
If an address has an @ sign in it, go directly to the host on the
-right- of the @-sign and pass everything to the left of it as the
"rest of the address". This should only happen -once- because there
should only be one @-sign. otherwise, the address -should- only
contain !'s -- evaluate left to right and send to each host in the
path -- if it contains a %, then send to the host to the -right- of
the token you're looking at. There's nothing about precedence since
their precedences are equal.
dan <island!argv@sun.com>
-----
My postings reflect my opinion only -- not the opinion of any company.
Technical Details
Message-ID:
<126303@sun.Eng.Sun.COM>Path:
arc1-ca.pugleaf.net!utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!uwm.edu!lll-winken!sun-barr!newstop!sun!turnpike!argvReferences:
<1989Oct5.053531.24832@egsner.cirr.com> <9672@b-tech.ann-arbor.mi.us> <586@trwrc.RC.TRW.COM> <Oct.9.13.58.43.1989.23064@NET.BIO.NET> <126099@sun.Eng.Sun.COM> <1175@unify.UUCP>Show Full Headers
Complete Article Headers
Path: arc1-ca.pugleaf.net!utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!uwm.edu!lll-winken!sun-barr!newstop!sun!turnpike!argv From: argv%turnpike@Sun.COM (Dan Heller) Newsgroups: comp.mail.misc Subject: use of % (was: Making smail2.5 understand <user>%<site>@<site>) Keywords: patches, smail2.5, %@ Message-ID: <126303@sun.Eng.Sun.COM> Date: 13 Oct 89 18:38:25 GMT References: <1989Oct5.053531.24832@egsner.cirr.com> <9672@b-tech.ann-arbor.mi.us> <586@trwrc.RC.TRW.COM> <Oct.9.13.58.43.1989.23064@NET.BIO.NET> <126099@sun.Eng.Sun.COM> <1175@unify.UUCP> Sender: news@sun.Eng.Sun.COM Reply-To: argv@sun.UUCP (Dan Heller) Organization: Sun Microsystems, Mountain View Lines: 80