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From: munnari!csc.anu.oz.au!gih900@UUNET.UU.NET (Geoff Huston)
Newsgroups: news.software.anu-news
Subject: Re: How about making Message-ID:'s more unique?
Message-ID: <8909060034.AA01981@uunet.uu.net>
Date: 6 Sep 89 13:35:27 GMT
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Reply-To: Geoff Huston <munnari!csc.anu.oz.au!gih900@UUNET.UU.NET>
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The message-id question is solved quite easily...
     
NEWSUTILITY.C
     
/*
 *  gen_id
 *
 *  generate a unique message id of the form <seq num>@<internet address>
 */
char genid[132];
     
char *gen_id()
{
  GRP savegrp;
  int seq;
     
  savegrp = newsgrp;
     
  grprab.rab$l_kbf = c$rfi(0);
  grprab.rab$b_ksz = 4;
  grprab.rab$b_krf = 1;
  grprab.rab$l_rop = RAB$M_WAT;
  grprab.rab$b_rac = RAB$C_KEY;
  _c$cks(sys$get(&grprab));
  seq = ++newsgrp.grp_iavd;
  _c$cks(sys$update(&grprab));
  sprintf(genid,"<%d.%X@%s>",seq,time(0),Node_address);
  s_to_lower(genid);
  return(genid);
}
     
The id format so generated is <sequence-number.hex-time@node>. The use of the
time rather than pid makes the message id unique whatever happens.
     
Geoff Huston