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From: spaf@cs.purdue.EDU (Gene Spafford)
Newsgroups: news.admin
Subject: Tired of bogus subject lines?
Message-ID: <7921@medusa.cs.purdue.edu>
Date: 8 Sep 89 19:01:44 GMT
Sender: news@cs.purdue.EDU
Reply-To: spaf@arthur.cs.purdue.edu (Gene Spafford)
Organization: Department of Computer Science, Purdue University
Lines: 153


This is a terrible kludge, but I am sooo tired of seeing those
bogus "Re^2:" subject lines....  They aren't the proper format
for follow-up subjects according to the RFC, and they don't track
with "rn" when trying to read news.  I was trying to catch up on
a few weeks of back news and kept reencountering threads of
discussions broken by that obnoxious "Re^2:"

So, I whipped up the enclosed program and installed it in our news
library with the following sys file line:

complain:world,all:BU:/usr/lib/news/complain < %s

It sends mail to the author of the article complaining about the
non-standard, non-conformant use of that string.  If enough of you
out there install it on your systems too, maybe the volume of mail
will convince people to fix the software.

As I said, it's a hack -- it works on Sequents and Suns, but no claims
that it will work anywhere else.  It also assumes you have
/usr/lib/sendmail as your mail agent.  Feel free to modify it to fit 
your system.

#include <stdio.h>
#include <ctype.h>

extern char    *malloc ();
extern int      strlen ();
extern FILE    *popen ();

#define NEWSTRING(ptr)  {if((ptr = malloc(slen+1)) == NULL) \
    return (-1); else strcpy(ptr, cptr);}

main ()
{
    char           *reply = NULL,
                   *sender = NULL,
                   *from = NULL,
                   *messageid = NULL;
    register char  *cptr;
    register int    slen;

    char            tbuf[512];


    while (fgets (tbuf, 512, stdin) != NULL)
    {
        if (*tbuf != '\n' && isspace(*tbuf))
		continue;
	else if (*tbuf == '\n')
		break;

   /* find the : and convert header to lower case */
	for (cptr = tbuf; *cptr && *cptr != ':'; cptr++)
	    if (isupper (*cptr))
		*cptr = tolower (*cptr);

   /* If no : found, we are out of the header */
	if (!*cptr)
	    break;

	*++cptr = '\0';
        cptr++;
	while (*cptr && *cptr == ' ')
	    cptr++;
	slen = strlen (cptr);
	if (cptr[slen - 1] == '\n')
	    cptr[--slen] = 0;

	if (strcmp ("subject:", tbuf) == 0)
	{
	    if (!isbadsub (cptr))
		return (0);
	}
	else if (strcmp ("sender:", tbuf) == 0)
	    NEWSTRING(sender)
	else if (strcmp ("reply-to:", tbuf) == 0)
	    NEWSTRING(reply)
	else if (strcmp ("from:", tbuf) == 0)
	    NEWSTRING(from)
	else if (strcmp ("message-id:", tbuf) == 0)
	    NEWSTRING(messageid)
    }

/* If we get this far, we have a bogus subject line.
 * We also have a reply address we can use to send
 * mail to tell them about it.
 */

    if (reply)
	complain (reply, messageid);
    else if (sender)
	complain (sender, messageid);
    else if (from)
	complain (from, messageid);
    else
	return (-1);

    return (0);
}

int 
isbadsub (subjectline)
char           *subjectline;
{
    int             i;

 /* only check here is for first 4 characters being "Re^2" */

    for (i = 0; i < 2; i++)
	if (isupper (subjectline[i]))
	    subjectline[i] = tolower (subjectline[i]);

    return (!strncmp (subjectline, "re^2:", 5));
}

#define OUT(ss)  fputs(ss, mailer)

complain (addressee, messageid)
char           *addressee,
               *messageid;
{
    FILE           *mailer;
    char	   hostname[64];


    gethostname(hostname, 64);
    mailer = popen ("/usr/lib/sendmail -t", "w");
    if (mailer == NULL)
    {
	perror ("Cannot open mailer");
	exit (-1);
    }

    fprintf (mailer, "To: %s\n", addressee);
    OUT("Subject: Invalid format in Usenet posting\n");
    OUT("Reply-to: nobody\n");
    fprintf(mailer, "From: news@%s\n\n", hostname);
    fprintf (mailer, "Your Usenet posting with message id %s\n", messageid);
    OUT("has an invalid subject line, as defined by RFC 1036, the ");
    OUT("Usenet format\nstandard document.\n\n");
    OUT("Your posting software is either broken or producing articles\n");
    OUT("that do not conform to the required standard format.\nPlease ");
    OUT("fix your software, or discontinue its use.\n\nThis was an ");
    OUT("automated message.");

	   pclose (mailer);
}
-- 
Gene Spafford
NSF/Purdue/U of Florida  Software Engineering Research Center,
Dept. of Computer Sciences, Purdue University, W. Lafayette IN 47907-2004
Internet:  spaf@cs.purdue.edu	uucp:	...!{decwrl,gatech,ucbvax}!purdue!spaf