pg@cxa.daresbury.ac.uk (Paul Griffiths) (05/26/90)
Hi, Is there anyone out there who can tell me how individual messages in a mailbox (ie /usr/spool/mail/$USER) are seperated from each other. The only distinguishable feature I can see is that each message begins with a line specifying who the message came from, ie From Info-unix-requests@uk.ac.nsfnet-relay Note that the "From" has NO `:' following it. Am I on the right track ??? Any help much appreciated. P.Griffiths. Daresbury Laboratory Graphics Group JANET: P.Griffiths@uk.ac.daresbury Internet: P.Griffiths%daresbury.ac.uk EARN/BITNET: P.Griffiths%daresbury.ac.uk@UKACRL UUCP: P.Griffiths%daresbury.ac.uk@ukc.uucp
brnstnd@stealth.acf.nyu.edu (05/28/90)
In article <23447@adm.BRL.MIL> pg@cxa.daresbury.ac.uk (Paul Griffiths) writes: > Is there anyone out there who can tell me how individual messages > in a mailbox (ie /usr/spool/mail/$USER) are seperated from each other. > The only distinguishable feature I can see is that each message begins > with a line specifying who the message came from, ie > From Info-unix-requests@uk.ac.nsfnet-relay > Note that the "From" has NO `:' following it. Am I on the right track ??? Yep, exactly right. You'll also note that if a line in the text of a message starts with From and a space, the mailer adds a > to the line; that way mailreaders won't think that it starts a new message. To be precise, the separator is "\n\nFrom ". There are other popular conventions for mail. The easiest to work with has every message in a separate file; unfortunately, this also wastes the most space. ---Dan
shwake@raysnec.UUCP (Ray Shwake) (05/29/90)
In article <1163:May2719:09:5690@stealth.acf.nyu.edu> brnstnd@stealth.acf.nyu.edu (Dan Bernstein) writes: >Yep, exactly right. You'll also note that if a line in the text of a >message starts with From and a space, the mailer adds a > to the line; >that way mailreaders won't think that it starts a new message. >To be precise, the separator is "\n\nFrom ". The > prefix on lines beginning with From is also intended to cut down on mail forgeries. Also, while "\n\nFrom " is present BETWEEN messages, the mailer will often simply look at each line and, if it begins with "From " judge it to be the start of the next message. You can confirm this by eliminating the blank line between messages and see if your mailer still separates your messages. >There are other popular conventions for mail. The easiest to work with >has every message in a separate file; unfortunately, this also wastes >the most space. This is an arguable position. Separating messages certainly does waste more space, but makes for a more complex directory structure by requiring (for efficiency sake) a separate directory for each subject collection, and makes movement between messages horribly inefficient.
volpe@underdog.crd.ge.com (Christopher R Volpe) (06/02/90)
In article <1163:May2719:09:5690@stealth.acf.nyu.edu> brnstnd@stealth.acf.nyu.edu (Dan Bernstein) writes: > >Yep, exactly right. You'll also note that if a line in the text of a >message starts with From and a space, the mailer adds a > to the line; >that way mailreaders won't think that it starts a new message. > >To be precise, the separator is "\n\nFrom ". The SunOS mail program that I use doesn't seem to use that as a separator. I sent a message to myself containing "From me@here" in the body of the message after two carriage returns, and indeed the ">" was automatically inserted, but I directly edited my spool file and removed the ">". When I invoked "mail" to read it, It didn't confuse the line in the text with the start of a new message, even though the ">" was no longer there. Could there be some control characters inserted somewhere? Chris Volpe G.E. Corporate Research and Development VOLPECR@CRD.GE.COM
rbottin@atl.calstate.edu (Richard John Botting) (06/03/90)
In article <1163:May2719:09:5690@stealth.acf.nyu.edu> brnstnd@stealth.acf.nyu.ed u (Dan Bernstein) writes: > >Yep, exactly right. You'll also note that if a line in the text of a >message starts with From and a space, the mailer adds a > to the line; >that way mailreaders won't think that it starts a new message. > >To be precise, the separator is "\n\nFrom ". Christopher R Volpe <volpe@underdog.crd.ge.com> adds >The SunOS mail program that I use doesn't seem to use that as >a separator. [...] >Could there be some control characters inserted somewhere? I would place small bet on 4 CTRL/A's because this is what about 50% of our mail system does at silicon.???.csusb.edu. The other half doesn't put in these characters (Please don't ask me why - I assume insanity on the part of the programmers) (whio would doubtless prefer to reamin anonymous) The fun starts when a third process parses mail...this appears to use the FIRST line to determine what the seperator between the messages is. In consequence we often find 6 or 7 or messages all masquerading as a single one... I wrote a script to clean my mail out, then some others tried it as well. As of tonight it went into service from root - as a crontab...It reads: : clean dumb sentinels from mail files cd /usr/spool/mail for mbox in * do echo $mbox ed - $mbox <<++++ 2>/dev/null g//s/// w q ++++ done By the way - g//s/// is not what it appears to be you'll have to insert 4 CTRL/A's ^here :-) Dr. Richard J Botting (The Aging Hacker) Computer Science Dept CalStateUniversity, San Bernardino. rbottin@atl.calstate.edu paaaaar@calstate.bitnet