long bezerk_cache_append (MAILSTREAM *stream,char *mailbox,
			  char *flags,char *date,
			  STRING *message)
{
  struct stat sbuf;
  int i,fd,ti,zn;
  char *s,*x,buf[BUFLEN],file[MAILTMPLEN],lock[MAILTMPLEN];
  time_t tp[2];
  MESSAGECACHE elt;
  char c = '\n';
  unsigned long j,n,ok = T;
  time_t t = time (0);
  unsigned long size = SIZE (message);
  unsigned long uf;
  long f = mail_parse_flags (stream ? stream : &bezerkproto,flags,&uf);
				/* parse date if given */
  if (date && !mail_parse_date (&elt,date)) {
    sprintf (buf,"Bad date in append: %s",date);
    mm_log (buf,ERROR);
    return NIL;
  }
				/* make sure valid mailbox */
  if (!bezerk_isvalid (mailbox,buf)) switch (errno) {
  case ENOENT:			/* no such file? */
    if (strcmp (ucase (strcpy (buf,mailbox)),"INBOX")) {
      mm_notify (stream,"[TRYCREATE] Must create mailbox before append",NIL);
      return NIL;
    }
    else break;
  case 0:			/* merely empty file? */
    break;
  case EINVAL:
    sprintf (buf,"Invalid Berkeley-format mailbox name: %s",mailbox);
    mm_log (buf,ERROR);
    return NIL;
  default:
    sprintf (buf,"Not a Berkeley-format mailbox: %s",mailbox);
    mm_log (buf,ERROR);
    return NIL;
  }
  if ((fd = bezerk_lock (dummy_file (file,mailbox),O_WRONLY|O_APPEND|O_CREAT,
			 S_IREAD|S_IWRITE,lock,LOCK_EX)) < 0) {
    sprintf (buf,"Can't open append mailbox: %s",strerror (errno));
    mm_log (buf,ERROR);
    return NIL;
  }

  mm_critical (stream);		/* go critical */
  fstat (fd,&sbuf);		/* get current file size */
  sprintf (buf,"From %s@%s ",myusername (),mylocalhost ());
				/* write the date given */
  if (date) mail_cdate (buf + strlen (buf),&elt);
  else strcat (buf,ctime (&t));	/* otherwise write the time now */
  i = strlen (buf);		/* initial buffer space used */
  while (ok && size--) {	/* copy text, tossing out CR's */
				/* if at start of line */
    if ((c == '\n') && (size > 5)) {
      n = GETPOS (message);	/* prepend a broket if needed */
      if ((SNX (message) == 'F') && (SNX (message) == 'r') &&
	  (SNX (message) == 'o') && (SNX (message) == 'm') &&
	  (SNX (message) == ' ')) {
				/* always write widget if unconditional */
	if (bezerk_fromwidget) ok = bezerk_append_putc (fd,buf,&i,'>');
	else {			/* hairier test, count length of this line */
	  for (j = 6; (j < size) && (SNX (message) != '\n'); j++);
	  if (j < size) {	/* copy line */
	    SETPOS (message,n);	/* restore position */
	    x = s = (char *) fs_get (j + 1);
	    while (j--) if ((c = SNX (message)) != '\015') *x++ = c;
	    *x = '\0';		/* tie off line */
	    VALID (s,x,ti,zn);	/* see if looks like need a widget */
	    if (ti) ok = bezerk_append_putc (fd,buf,&i,'>');
	    fs_give ((void **) &s);
	  }
	}
      }
      SETPOS (message,n);	/* restore position as needed */
    }
				/* copy another character */
    if ((c = SNX (message)) != '\015') ok = bezerk_append_putc (fd,buf,&i,c);
  }
				/* write trailing newline */
  if (ok) ok = bezerk_append_putc (fd,buf,&i,'\n');
  if (!(ok && (ok = (write (fd,buf,i) >= 0)) && (ok = !fsync (fd)))) {
    sprintf (buf,"Message append failed: %s",strerror (errno));
    mm_log (buf,ERROR);
    ftruncate (fd,sbuf.st_size);
  }
  tp[0] = sbuf.st_atime;	/* preserve atime */
  tp[1] = time (0);		/* set mtime to now */
  utime (file,tp);		/* set the times */
  bezerk_unlock (fd,NIL,lock);	/* unlock and close mailbox */
  mm_nocritical (stream);	/* release critical */
  return ok;			/* return success */
}