Path: 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 %@) 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> <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 [ 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 ----- My postings reflect my opinion only -- not the opinion of any company.