/* make sure valid name */    for (s = mailbox + 4; s && *s;) {      if (isdigit (*s)) s++;	/* digit, check this node further... */				/* all digit node, barf */      else if (*s == '/') s = NIL;				/* non-digit in node, skip to next node */      else if (s = strchr (s+1,'/')) s++;      else tmp[0] = NIL;	/* no more nodes, good name */    }  if (tmp[0]) {			/* was there an error in the name? */    mm_log (tmp,ERROR);		/* yes, log it */    return NIL;  }				/* must not already exist */  if (mh_isvalid (mailbox,tmp,NIL)) {    sprintf (tmp,"Can't create mailbox %.80s: mailbox already exists",mailbox);    mm_log (tmp,ERROR);    return NIL;  }  if (!mh_path) return NIL;	/* sorry */				/* try to make it */  if (!(mh_file (tmp,mailbox) && dummy_create_path (stream,strcat (tmp,"/")))){    sprintf (tmp,"Can't create mailbox %.80s: %s",mailbox,strerror (errno));    mm_log (tmp,ERROR);    return NIL;  }  return T;			/* return success */}/* MH mail delete mailbox *	    mailbox name to delete * Returns: T on success, NIL on failure */long mh_delete (MAILSTREAM *stream,char *mailbox){  DIR *dirp;  struct direct *d;  int i;  char tmp[MAILTMPLEN];  if (!(mailbox[0] == '#' && (mailbox[1] == 'm' || mailbox[1] == 'M') &&	(mailbox[2] == 'h' || mailbox[2] == 'H') && mailbox[3] == '/')) {    sprintf (tmp,"Can't delete mailbox %.80s: invalid MH-format name",mailbox);    mm_log (tmp,ERROR);    return NIL;  }				/* is mailbox valid? */  if (!mh_isvalid (mailbox,tmp,NIL)){    sprintf (tmp,"Can't delete mailbox %.80s: no such mailbox",mailbox);    mm_log (tmp,ERROR);    return NIL;  }				/* get name of directory */  i = strlen (mh_file (tmp,mailbox));  if (dirp = opendir (tmp)) {	/* open directory */    tmp[i++] = '/';		/* now apply trailing delimiter */    while (d = readdir (dirp))	/* massacre all numeric or comma files */      if (mh_select (d) || (*d->d_name == ',') ||	  !strcmp (d->d_name,MHSEQUENCE)) {	strcpy (tmp + i,d->d_name);	unlink (tmp);		/* sayonara */      }    closedir (dirp);		/* flush directory */  }				/* try to remove the directory */  if (rmdir (mh_file (tmp,mailbox))) {    sprintf (tmp,"Can't delete mailbox %.80s: %s",mailbox,strerror (errno));    mm_log (tmp,ERROR);    return NIL;  }  return T;			/* return success */}/* MH mail rename mailbox * Accepts: MH mail stream *	    old mailbox name *	    new mailbox name * Returns: T on success, NIL on failure */long mh_rename (MAILSTREAM *stream,char *old,char *newname){  char c,*s,tmp[MAILTMPLEN],tmp1[MAILTMPLEN];  struct stat sbuf;  if (!(old[0] == '#' && (old[1] == 'm' || old[1] == 'M') &&	(old[2] == 'h' || old[2] == 'H') && old[3] == '/'))    sprintf (tmp,"Can't delete mailbox %.80s: invalid MH-format name",old);				/* old mailbox name must be valid */  else if (!mh_isvalid (old,tmp,NIL))    sprintf (tmp,"Can't rename mailbox %.80s: no such mailbox",old);  else if (!(newname[0] == '#' && (newname[1] == 'm' || newname[1] == 'M') &&	(newname[2] == 'h' || newname[2] == 'H') && newname[3] == '/'))    sprintf (tmp,"Can't rename to mailbox %.80s: invalid MH-format name",	     newname);				/* new mailbox name must not be valid */  else if (mh_isvalid (newname,tmp,NIL))    sprintf (tmp,"Can't rename to mailbox %.80s: destination already exists",	     newname);				/* success if can rename the directory */  else {			/* found superior to destination name? */    if (s = strrchr (mh_file (tmp1,newname),'/')) {      c = *++s;			/* remember first character of inferior */      *s = '\0';		/* tie off to get just superior */				/* name doesn't exist, create it */      if ((stat (tmp1,&sbuf) || ((sbuf.st_mode & S_IFMT) != S_IFDIR)) &&	  !dummy_create (stream,tmp1)) return NIL;      *s = c;			/* restore full name */    }    if (!rename (mh_file (tmp,old),tmp1)) return T;    sprintf (tmp,"Can't rename mailbox %.80s to %.80s: %s",	     old,newname,strerror (errno));  }  mm_log (tmp,ERROR);		/* something failed */  return NIL;}/* MH mail open * Accepts: stream to open * Returns: stream on success, NIL on failure */MAILSTREAM *mh_open (MAILSTREAM *stream){  char tmp[MAILTMPLEN];  if (!stream) return &mhproto;	/* return prototype for OP_PROTOTYPE call */  if (stream->local) fatal ("mh recycle stream");  stream->local = fs_get (sizeof (MHLOCAL));				/* note if an INBOX or not */  stream->inbox = !strcmp (ucase (strcpy (tmp,stream->mailbox)),"#MHINBOX");  mh_file (tmp,stream->mailbox);/* get directory name */  LOCAL->dir = cpystr (tmp);	/* copy directory name for later */				/* make temporary buffer */  LOCAL->buf = (char *) fs_get ((LOCAL->buflen = MAXMESSAGESIZE) + 1);  LOCAL->scantime = 0;		/* not scanned yet */  LOCAL->cachedtexts = 0;	/* no cached texts */  stream->sequence++;		/* bump sequence number */				/* parse mailbox */  stream->nmsgs = stream->recent = 0;  if (!mh_ping (stream)) return NIL;  if (!(stream->nmsgs || stream->silent))    mm_log ("Mailbox is empty",(long) NIL);  return stream;		/* return stream to caller */}/* MH mail close * Accepts: MAIL stream *	    close options */void mh_close (MAILSTREAM *stream,long options){  if (LOCAL) {			/* only if a file is open */    int silent = stream->silent;    stream->silent = T;		/* note this stream is dying */    if (options & CL_EXPUNGE) mh_expunge (stream);    if (LOCAL->dir) fs_give ((void **) &LOCAL->dir);				/* free local scratch buffer */    if (LOCAL->buf) fs_give ((void **) &LOCAL->buf);				/* nuke the local data */    fs_give ((void **) &stream->local);    stream->dtb = NIL;		/* log out the DTB */    stream->silent = silent;	/* reset silent state */  }}/* MH mail fetch fast information * Accepts: MAIL stream *	    sequence *	    option flags */void mh_fast (MAILSTREAM *stream,char *sequence,long flags){  unsigned long i,j;				/* ugly and slow */  if (stream && LOCAL && ((flags & FT_UID) ?			  mail_uid_sequence (stream,sequence) :			  mail_sequence (stream,sequence)))    for (i = 1; i <= stream->nmsgs; i++)      if (mail_elt (stream,i)->sequence) mh_header (stream,i,&j,NIL);}/* MH mail fetch message header * Accepts: MAIL stream *	    message # to fetch *	    pointer to returned header text length *	    option flags * Returns: message header in RFC822 format */char *mh_header (MAILSTREAM *stream,unsigned long msgno,unsigned long *length,		 long flags){  unsigned long i,hdrsize;  int fd;  char *t;  struct stat sbuf;  struct tm *tm;  MESSAGECACHE *elt;  *length = 0;			/* default to empty */  if (flags & FT_UID) return "";/* UID call "impossible" */  elt = mail_elt (stream,msgno);/* get elt */  if (!elt->private.msg.header.text.data) {				/* purge cache if too big */    if (LOCAL->cachedtexts > max (stream->nmsgs * 4096,2097152)) {      mail_gc (stream,GC_TEXTS);/* just can't keep that much */      LOCAL->cachedtexts = 0;    }				/* build message file name */    sprintf (LOCAL->buf,"%s/%lu",LOCAL->dir,elt->private.uid);    if ((fd = open (LOCAL->buf,O_RDONLY,NIL)) < 0) return "";    fstat (fd,&sbuf);		/* get size of message */				/* make plausible IMAPish date string */    tm = gmtime (&sbuf.st_mtime);    elt->day = tm->tm_mday; elt->month = tm->tm_mon + 1;    elt->year = tm->tm_year + 1900 - BASEYEAR;    elt->hours = tm->tm_hour; elt->minutes = tm->tm_min;    elt->seconds = tm->tm_sec;    elt->zhours = 0; elt->zminutes = 0;				/* is buffer big enough? */    if (sbuf.st_size > LOCAL->buflen) {      fs_give ((void **) &LOCAL->buf);      LOCAL->buf = (char *) fs_get ((LOCAL->buflen = sbuf.st_size) + 1);    }				/* slurp message */    read (fd,LOCAL->buf,sbuf.st_size);				/* tie off file */    LOCAL->buf[sbuf.st_size] = '\0';    close (fd);			/* flush message file */				/* find end of header */    for (i = 0,t = LOCAL->buf; *t && !(i && (*t == '\n')); i = (*t++ == '\n'));				/* number of header bytes */    hdrsize = (*t ? ++t : t) - LOCAL->buf;    elt->rfc822_size =		/* size of entire message in CRLF form */      (elt->private.msg.header.text.size =       strcrlfcpy ((char **) &elt->private.msg.header.text.data,&i,LOCAL->buf,		   hdrsize)) +	 (elt->private.msg.text.text.size =	  strcrlfcpy ((char **) &elt->private.msg.text.text.data,&i,t,		      sbuf.st_size - hdrsize));				/* add to cached size */    LOCAL->cachedtexts += elt->rfc822_size;  }  *length = elt->private.msg.header.text.size;  return (char *) elt->private.msg.header.text.data;}/* MH mail fetch message text (body only) * Accepts: MAIL stream *	    message # to fetch *	    pointer to returned stringstruct *	    option flags * Returns: T on success, NIL on failure */long mh_text (MAILSTREAM *stream,unsigned long msgno,STRING *bs,long flags){  unsigned long i;  MESSAGECACHE *elt;				/* UID call "impossible" */  if (flags & FT_UID) return NIL;  elt = mail_elt (stream,msgno);/* get elt */				/* snarf message if don't have it yet */  if (!elt->private.msg.text.text.data) {    mh_header (stream,msgno,&i,flags);    if (!elt->private.msg.text.text.data) return NIL;  }  if (!(flags & FT_PEEK)) {	/* mark as seen */    mail_elt (stream,msgno)->seen = T;    mm_flags (stream,msgno);  }  if (!elt->private.msg.text.text.data) return NIL;  INIT (bs,mail_string,elt->private.msg.text.text.data,	elt->private.msg.text.text.size);  return T;}/* MH mail ping mailbox * Accepts: MAIL stream * Returns: T if stream alive, else NIL */long mh_ping (MAILSTREAM *stream){  MAILSTREAM *sysibx = NIL;  MESSAGECACHE *elt,*selt;  struct stat sbuf;  char *s,tmp[MAILTMPLEN];  int fd;  unsigned long i,j,r,old;  long nmsgs = stream->nmsgs;  long recent = stream->recent;  int silent = stream->silent;  if (stat (LOCAL->dir,&sbuf)) { /* directory exists? */    if (stream->inbox) return T;    sprintf (tmp,"Can't open mailbox %.80s: no such mailbox",stream->mailbox);    mm_log (tmp,ERROR);    return NIL;  }  stream->silent = T;		/* don't pass up mm_exists() events yet */  if (sbuf.st_ctime != LOCAL->scantime) {    struct direct **names = NIL;    long nfiles = scandir (LOCAL->dir,&names,mh_select,mh_numsort);    if (nfiles < 0) nfiles = 0;	/* in case error */    old = stream->uid_last;				/* note scanned now */    LOCAL->scantime = sbuf.st_ctime;				/* scan directory */    for (i = 0; i < nfiles; ++i) {				/* if newly seen, add to list */      if ((j = atoi (names[i]->d_name)) > old) {	mail_exists (stream,++nmsgs);	stream->uid_last = (elt = mail_elt (stream,nmsgs))->private.uid = j;	elt->valid = T;		/* note valid flags */	if (old) {		/* other than the first pass? */	  elt->recent = T;	/* yup, mark as recent */	  recent++;		/* bump recent count */	}	else {			/* see if already read */	  sprintf (tmp,"%s/%s",LOCAL->dir,names[i]->d_name);	  stat (tmp,&sbuf);	/* get inode poop */	  if (sbuf.st_atime > sbuf.st_mtime) elt->seen = T;	}      }      fs_give ((void **) &names[i]);    }				/* free directory */    if (s = (void *) names) fs_give ((void **) &s);  }				/* if INBOX, snarf from system INBOX  */  if (stream->inbox && strcmp (sysinbox (),stream->mailbox)) {    old = stream->uid_last;    mm_critical (stream);	/* go critical */    stat (sysinbox (),&sbuf);	/* see if anything there */				/* can get sysinbox mailbox? */    if (sbuf.st_size && (sysibx = mail_open (sysibx,sysinbox (),OP_SILENT))	&& (!sysibx->rdonly) && (r = sysibx->nmsgs)) {      for (i = 1; i <= r; ++i) {/* for each message in sysinbox mailbox */				/* build file name we will use */	sprintf (LOCAL->buf,"%s/%lu",LOCAL->dir,++old);				/* snarf message from Berkeley mailbox */	selt = mail_elt (sysibx,i);	if (((fd = open (LOCAL->buf,O_WRONLY|O_CREAT|O_EXCL,			 S_IREAD|S_IWRITE)) >= 0) &&	    (s = mail_fetchheader_full (sysibx,i,NIL,&j,FT_INTERNAL)) &&