Initial Alpine Version

1 files changed, 809 insertions, 0 deletions

diff --git a/imap/src/osdep/unix/dummy.c b/imap/src/osdep/unix/dummy.c
new file mode 100644
index 00000000..b003a0ba
--- /dev/null
+++ b/imap/src/osdep/unix/dummy.c
@@ -0,0 +1,809 @@
+/* ========================================================================
+ * Copyright 1988-2007 University of Washington
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * 
+ * ========================================================================
+ */
+
+/*
+ * Program:	Dummy routines
+ *
+ * Author:	Mark Crispin
+ *		Networks and Distributed Computing
+ *		Computing & Communications
+ *		University of Washington
+ *		Administration Building, AG-44
+ *		Seattle, WA  98195
+ *		Internet: MRC@CAC.Washington.EDU
+ *
+ * Date:	9 May 1991
+ * Last Edited:	1 June 2007
+ */
+
+
+#include <stdio.h>
+#include <ctype.h>
+#include <errno.h>
+extern int errno;		/* just in case */
+#include "mail.h"
+#include "osdep.h"
+#include <pwd.h>
+#include <sys/stat.h>
+#include "dummy.h"
+#include "misc.h"
+
+/* Function prototypes */
+
+DRIVER *dummy_valid (char *name);
+void *dummy_parameters (long function,void *value);
+void dummy_list_work (MAILSTREAM *stream,char *dir,char *pat,char *contents,
+		      long level);
+long dummy_listed (MAILSTREAM *stream,char delimiter,char *name,
+		   long attributes,char *contents);
+long dummy_subscribe (MAILSTREAM *stream,char *mailbox);
+MAILSTREAM *dummy_open (MAILSTREAM *stream);
+void dummy_close (MAILSTREAM *stream,long options);
+long dummy_ping (MAILSTREAM *stream);
+void dummy_check (MAILSTREAM *stream);
+long dummy_expunge (MAILSTREAM *stream,char *sequence,long options);
+long dummy_copy (MAILSTREAM *stream,char *sequence,char *mailbox,long options);
+long dummy_append (MAILSTREAM *stream,char *mailbox,append_t af,void *data);
+
+/* Dummy routines */
+
+
+/* Driver dispatch used by MAIL */
+
+DRIVER dummydriver = {
+  "dummy",			/* driver name */
+  DR_LOCAL|DR_MAIL,		/* driver flags */
+  (DRIVER *) NIL,		/* next driver */
+  dummy_valid,			/* mailbox is valid for us */
+  dummy_parameters,		/* manipulate parameters */
+  dummy_scan,			/* scan mailboxes */
+  dummy_list,			/* list mailboxes */
+  dummy_lsub,			/* list subscribed mailboxes */
+  dummy_subscribe,		/* subscribe to mailbox */
+  NIL,				/* unsubscribe from mailbox */
+  dummy_create,			/* create mailbox */
+  dummy_delete,			/* delete mailbox */
+  dummy_rename,			/* rename mailbox */
+  mail_status_default,		/* status of mailbox */
+  dummy_open,			/* open mailbox */
+  dummy_close,			/* close mailbox */
+  NIL,				/* fetch message "fast" attributes */
+  NIL,				/* fetch message flags */
+  NIL,				/* fetch overview */
+  NIL,				/* fetch message structure */
+  NIL,				/* fetch header */
+  NIL,				/* fetch text */
+  NIL,				/* fetch message data */
+  NIL,				/* unique identifier */
+  NIL,				/* message number from UID */
+  NIL,				/* modify flags */
+  NIL,				/* per-message modify flags */
+  NIL,				/* search for message based on criteria */
+  NIL,				/* sort messages */
+  NIL,				/* thread messages */
+  dummy_ping,			/* ping mailbox to see if still alive */
+  dummy_check,			/* check for new messages */
+  dummy_expunge,		/* expunge deleted messages */
+  dummy_copy,			/* copy messages to another mailbox */
+  dummy_append,			/* append string message to mailbox */
+  NIL				/* garbage collect stream */
+};
+
+				/* prototype stream */
+MAILSTREAM dummyproto = {&dummydriver};
+
+/* Dummy validate mailbox
+ * Accepts: mailbox name
+ * Returns: our driver if name is valid, NIL otherwise
+ */
+
+DRIVER *dummy_valid (char *name)
+{
+  char *s,tmp[MAILTMPLEN];
+  struct stat sbuf;
+				/* must be valid local mailbox */
+  if (name && *name && (*name != '{') && (s = mailboxfile (tmp,name))) {
+				/* indeterminate clearbox INBOX */
+    if (!*s) return &dummydriver;
+    else if (!stat (s,&sbuf)) switch (sbuf.st_mode & S_IFMT) {
+    case S_IFREG:
+    case S_IFDIR:
+      return &dummydriver;
+    }
+				/* blackbox INBOX does not exist yet */
+    else if (!compare_cstring (name,"INBOX")) return &dummydriver;
+  }
+  return NIL;
+}
+
+
+/* Dummy manipulate driver parameters
+ * Accepts: function code
+ *	    function-dependent value
+ * Returns: function-dependent return value
+ */
+
+void *dummy_parameters (long function,void *value)
+{
+  void *ret = NIL;
+  switch ((int) function) {
+  case GET_INBOXPATH:
+    if (value) ret = dummy_file ((char *) value,"INBOX");
+    break;
+  }
+  return ret;
+}
+
+/* Dummy scan mailboxes
+ * Accepts: mail stream
+ *	    reference
+ *	    pattern to search
+ *	    string to scan
+ */
+
+void dummy_scan (MAILSTREAM *stream,char *ref,char *pat,char *contents)
+{
+  DRIVER *drivers;
+  char *s,test[MAILTMPLEN],file[MAILTMPLEN];
+  long i;
+  if (!pat || !*pat) {		/* empty pattern? */
+    if (dummy_canonicalize (test,ref,"*")) {
+				/* tie off name at root */
+      if (s = strchr (test,'/')) *++s = '\0';
+      else test[0] = '\0';
+      dummy_listed (stream,'/',test,LATT_NOSELECT,NIL);
+    }
+  }
+				/* get canonical form of name */
+  else if (dummy_canonicalize (test,ref,pat)) {
+				/* found any wildcards? */
+    if (s = strpbrk (test,"%*")) {
+				/* yes, copy name up to that point */
+      strncpy (file,test,i = s - test);
+      file[i] = '\0';		/* tie off */
+    }
+    else strcpy (file,test);	/* use just that name then */
+    if (s = strrchr (file,'/')){/* find directory name */
+      *++s = '\0';		/* found, tie off at that point */
+      s = file;
+    }
+				/* silly case */
+    else if ((file[0] == '~') || (file[0] == '#')) s = file;
+				/* do the work */
+    dummy_list_work (stream,s,test,contents,0);
+				/* always an INBOX */
+    if (pmatch ("INBOX",ucase (test))) {
+				/* done if have a dirfmt INBOX */
+      for (drivers = (DRIVER *) mail_parameters (NIL,GET_DRIVERS,NIL);
+	   drivers && !(!(drivers->flags & DR_DISABLE) &&
+			(drivers->flags & DR_DIRFMT) &&
+			(*drivers->valid) ("INBOX")); drivers = drivers->next);
+				/* list INBOX appropriately */
+      dummy_listed (stream,drivers ? '/' : NIL,"INBOX",
+		    drivers ? NIL : LATT_NOINFERIORS,contents);
+    }
+  }
+}
+
+
+/* Dummy list mailboxes
+ * Accepts: mail stream
+ *	    reference
+ *	    pattern to search
+ */
+
+void dummy_list (MAILSTREAM *stream,char *ref,char *pat)
+{
+  dummy_scan (stream,ref,pat,NIL);
+}
+
+/* Dummy list subscribed mailboxes
+ * Accepts: mail stream
+ *	    reference
+ *	    pattern to search
+ */
+
+void dummy_lsub (MAILSTREAM *stream,char *ref,char *pat)
+{
+  void *sdb = NIL;
+  char *s,*t,test[MAILTMPLEN],tmp[MAILTMPLEN];
+  int showuppers = pat[strlen (pat) - 1] == '%';
+				/* get canonical form of name */
+  if (dummy_canonicalize (test,ref,pat) && (s = sm_read (&sdb))) do
+    if (*s != '{') {
+      if (!compare_cstring (s,"INBOX") &&
+	  pmatch ("INBOX",ucase (strcpy (tmp,test))))
+	mm_lsub (stream,NIL,s,LATT_NOINFERIORS);
+      else if (pmatch_full (s,test,'/')) mm_lsub (stream,'/',s,NIL);
+      else while (showuppers && (t = strrchr (s,'/'))) {
+	*t = '\0';		/* tie off the name */
+	if (pmatch_full (s,test,'/')) mm_lsub (stream,'/',s,LATT_NOSELECT);
+      }
+    }
+  while (s = sm_read (&sdb));	/* until no more subscriptions */
+}
+
+
+/* Dummy subscribe to mailbox
+ * Accepts: mail stream
+ *	    mailbox to add to subscription list
+ * Returns: T on success, NIL on failure
+ */
+
+long dummy_subscribe (MAILSTREAM *stream,char *mailbox)
+{
+  char *s,tmp[MAILTMPLEN];
+  struct stat sbuf;
+				/* must be valid local mailbox */
+  if ((s = mailboxfile (tmp,mailbox)) && *s && !stat (s,&sbuf))
+    switch (sbuf.st_mode & S_IFMT) {
+    case S_IFDIR:		/* allow but snarl */
+      sprintf (tmp,"CLIENT BUG DETECTED: subscribe of non-mailbox directory %.80s",
+	       mailbox);
+      MM_NOTIFY (stream,tmp,WARN);
+    case S_IFREG:
+      return sm_subscribe (mailbox);
+    }
+  sprintf (tmp,"Can't subscribe %.80s: not a mailbox",mailbox);
+  MM_LOG (tmp,ERROR);
+  return NIL;
+}
+
+/* Dummy list mailboxes worker routine
+ * Accepts: mail stream
+ *	    directory name to search
+ *	    search pattern
+ *	    string to scan
+ *	    search level
+ */
+
+void dummy_list_work (MAILSTREAM *stream,char *dir,char *pat,char *contents,
+		      long level)
+{
+  DRIVER *drivers;
+  dirfmttest_t dt;
+  DIR *dp;
+  struct direct *d;
+  struct stat sbuf;
+  char tmp[MAILTMPLEN],path[MAILTMPLEN];
+  size_t len = 0;
+				/* punt if bogus name */
+  if (!mailboxdir (tmp,dir,NIL)) return;
+  if (dp = opendir (tmp)) {	/* do nothing if can't open directory */
+				/* see if a non-namespace directory format */
+    for (drivers = (DRIVER *) mail_parameters (NIL,GET_DRIVERS,NIL), dt = NIL;
+	 dir && !dt && drivers; drivers = drivers->next)
+      if (!(drivers->flags & DR_DISABLE) && (drivers->flags & DR_DIRFMT) &&
+	  (*drivers->valid) (dir))
+	dt = mail_parameters ((*drivers->open) (NIL),GET_DIRFMTTEST,NIL);
+				/* list it if at top-level */
+    if (!level && dir && pmatch_full (dir,pat,'/') && !pmatch (dir,"INBOX"))
+      dummy_listed (stream,'/',dir,dt ? NIL : LATT_NOSELECT,contents);
+
+				/* scan directory, ignore . and .. */
+    if (!dir || dir[(len = strlen (dir)) - 1] == '/') while (d = readdir (dp))
+      if ((!(dt && (*dt) (d->d_name))) &&
+	  ((d->d_name[0] != '.') ||
+	   (((long) mail_parameters (NIL,GET_HIDEDOTFILES,NIL)) ? NIL :
+	    (d->d_name[1] && (((d->d_name[1] != '.') || d->d_name[2]))))) &&
+	  ((len + strlen (d->d_name)) <= NETMAXMBX)) {
+				/* see if name is useful */
+	if (dir) sprintf (tmp,"%s%s",dir,d->d_name);
+	else strcpy (tmp,d->d_name);
+				/* make sure useful and can get info */
+	if ((pmatch_full (strcpy (path,tmp),pat,'/') ||
+	     pmatch_full (strcat (path,"/"),pat,'/') ||
+	     dmatch (path,pat,'/')) &&
+	    mailboxdir (path,dir,"x") && (len = strlen (path)) &&
+	    strcpy (path+len-1,d->d_name) && !stat (path,&sbuf)) {
+				/* only interested in file type */
+	  switch (sbuf.st_mode & S_IFMT) {
+	  case S_IFDIR:		/* directory? */
+				/* form with trailing / */
+	    sprintf (path,"%s/",tmp);
+				/* skip listing if INBOX */
+	    if (!pmatch (tmp,"INBOX")) {
+	      if (pmatch_full (tmp,pat,'/')) {
+		if (!dummy_listed (stream,'/',tmp,LATT_NOSELECT,contents))
+		  break;
+	      }
+				/* try again with trailing / */
+	      else if (pmatch_full (path,pat,'/') &&
+		       !dummy_listed (stream,'/',path,LATT_NOSELECT,contents))
+		break;
+	    }
+	    if (dmatch (path,pat,'/') &&
+		(level < (long) mail_parameters (NIL,GET_LISTMAXLEVEL,NIL)))
+	      dummy_list_work (stream,path,pat,contents,level+1);
+	    break;
+	  case S_IFREG:		/* ordinary name */
+	    /* Must use ctime for systems that don't update mtime properly */
+	    if (pmatch_full (tmp,pat,'/') && compare_cstring (tmp,"INBOX"))
+	      dummy_listed (stream,'/',tmp,LATT_NOINFERIORS +
+			    ((sbuf.st_size && (sbuf.st_atime < sbuf.st_ctime))?
+			     LATT_MARKED : LATT_UNMARKED),contents);
+	    break;
+	  }
+	}
+      }
+    closedir (dp);		/* all done, flush directory */
+  }
+}
+
+/* Scan file for contents
+ * Accepts: driver to use
+ *	    file name
+ *	    desired contents
+ *	    length of contents
+ *	    size of file
+ * Returns: NIL if contents not found, T if found
+ */
+
+long scan_contents (DRIVER *dtb,char *name,char *contents,
+		    unsigned long csiz,unsigned long fsiz)
+{
+  scancontents_t sc = dtb ?
+    (scancontents_t) (*dtb->parameters) (GET_SCANCONTENTS,NIL) : NIL;
+  return (*(sc ? sc : dummy_scan_contents)) (name,contents,csiz,fsiz);
+}
+
+
+/* Scan file for contents
+ * Accepts: file name
+ *	    desired contents
+ *	    length of contents
+ *	    size of file
+ * Returns: NIL if contents not found, T if found
+ */
+
+#define BUFSIZE 4*MAILTMPLEN
+
+long dummy_scan_contents (char *name,char *contents,unsigned long csiz,
+			  unsigned long fsiz)
+{
+  int fd;
+  unsigned long ssiz,bsiz;
+  char *buf;
+				/* forget it if can't select or open */
+  if ((fd = open (name,O_RDONLY,NIL)) >= 0) {
+				/* get buffer including slop */    
+    buf = (char *) fs_get (BUFSIZE + (ssiz = 4 * ((csiz / 4) + 1)) + 1);
+    memset (buf,'\0',ssiz);	/* no slop area the first time */
+    while (fsiz) {		/* until end of file */
+      read (fd,buf+ssiz,bsiz = min (fsiz,BUFSIZE));
+      if (search ((unsigned char *) buf,bsiz+ssiz,
+		  (unsigned char *) contents,csiz)) break;
+      memcpy (buf,buf+BUFSIZE,ssiz);
+      fsiz -= bsiz;		/* note that we read that much */
+    }
+    fs_give ((void **) &buf);	/* flush buffer */
+    close (fd);			/* finished with file */
+    if (fsiz) return T;		/* found */
+  }
+  return NIL;			/* not found */
+}
+
+/* Mailbox found
+ * Accepts: MAIL stream
+ *	    hierarchy delimiter
+ *	    mailbox name
+ *	    attributes
+ *	    contents to search before calling mm_list()
+ * Returns: NIL if should abort hierarchy search, else T (currently always)
+ */
+
+long dummy_listed (MAILSTREAM *stream,char delimiter,char *name,
+		   long attributes,char *contents)
+{
+  DRIVER *d;
+  DIR *dp;
+  struct direct *dr;
+  dirfmttest_t dt;
+  unsigned long csiz;
+  struct stat sbuf;
+  int nochild;
+  char *s,tmp[MAILTMPLEN];
+  if (!(attributes & LATT_NOINFERIORS) && mailboxdir (tmp,name,NIL) &&
+      (dp = opendir (tmp))) {	/* if not \NoInferiors */
+				/* locate dirfmttest if any */
+    for (d = (DRIVER *) mail_parameters (NIL,GET_DRIVERS,NIL), dt = NIL;
+	 !dt && d; d = d->next)
+      if (!(d->flags & DR_DISABLE) && (d->flags & DR_DIRFMT) &&
+	  (*d->valid) (name))
+	dt = mail_parameters ((*d->open) (NIL),GET_DIRFMTTEST,NIL);
+				/* scan directory for children */
+    for (nochild = T; nochild && (dr = readdir (dp)); )
+      if ((!(dt && (*dt) (dr->d_name))) &&
+	  ((dr->d_name[0] != '.') ||
+	   (((long) mail_parameters (NIL,GET_HIDEDOTFILES,NIL)) ? NIL :
+	    (dr->d_name[1] && ((dr->d_name[1] != '.') || dr->d_name[2])))))
+	nochild = NIL;
+    attributes |= nochild ? LATT_HASNOCHILDREN : LATT_HASCHILDREN;
+    closedir (dp);		/* all done, flush directory */
+  }
+  d = NIL;			/* don't \NoSelect dir if it has a driver */
+  if ((attributes & LATT_NOSELECT) && (d = mail_valid (NIL,name,NIL)) &&
+      (d != &dummydriver)) attributes &= ~LATT_NOSELECT;
+  if (!contents ||		/* notify main program */
+      (!(attributes & LATT_NOSELECT) && (csiz = strlen (contents)) &&
+       (s = mailboxfile (tmp,name)) &&
+       (*s || (s = mail_parameters (NIL,GET_INBOXPATH,tmp))) &&
+       !stat (s,&sbuf) && (d || (csiz <= sbuf.st_size)) &&
+       SAFE_SCAN_CONTENTS (d,tmp,contents,csiz,sbuf.st_size)))
+    mm_list (stream,delimiter,name,attributes);
+  return T;
+}
+
+/* Dummy create mailbox
+ * Accepts: mail stream
+ *	    mailbox name to create
+ * Returns: T on success, NIL on failure
+ */
+
+long dummy_create (MAILSTREAM *stream,char *mailbox)
+{
+  char *s,tmp[MAILTMPLEN];
+  long ret = NIL;
+				/* validate name */
+  if (!(compare_cstring (mailbox,"INBOX") && (s = dummy_file (tmp,mailbox)))) {
+    sprintf (tmp,"Can't create %.80s: invalid name",mailbox);
+    MM_LOG (tmp,ERROR);
+  }
+				/* create the name, done if made directory */
+  else if ((ret = dummy_create_path (stream,tmp,get_dir_protection(mailbox)))&&
+	   (s = strrchr (s,'/')) && !s[1]) return T;
+  return ret ? set_mbx_protections (mailbox,tmp) : NIL;
+}
+
+/* Dummy create path
+ * Accepts: mail stream
+ *	    path name to create
+ *	    directory mode
+ * Returns: T on success, NIL on failure
+ */
+
+long dummy_create_path (MAILSTREAM *stream,char *path,long dirmode)
+{
+  struct stat sbuf;
+  char c,*s,tmp[MAILTMPLEN];
+  int fd;
+  long ret = NIL;
+  char *t = strrchr (path,'/');
+  int wantdir = t && !t[1];
+  int mask = umask (0);
+  if (wantdir) *t = '\0';	/* flush trailing delimiter for directory */
+  if (s = strrchr (path,'/')) {	/* found superior to this name? */
+    c = *++s;			/* remember first character of inferior */
+    *s = '\0';			/* tie off to get just superior */
+				/* name doesn't exist, create it */
+    if ((stat (path,&sbuf) || ((sbuf.st_mode & S_IFMT) != S_IFDIR)) &&
+	!dummy_create_path (stream,path,dirmode)) {
+      umask (mask);		/* restore mask */
+      return NIL;
+    }
+    *s = c;			/* restore full name */
+  }
+  if (wantdir) {		/* want to create directory? */
+    ret = !mkdir (path,(int) dirmode);
+    *t = '/';			/* restore directory delimiter */
+  }
+				/* create file */
+  else if ((fd = open (path,O_WRONLY|O_CREAT|O_EXCL,
+		       (long) mail_parameters(NIL,GET_MBXPROTECTION,NIL))) >=0)
+    ret = !close (fd);
+  if (!ret) {			/* error? */
+    sprintf (tmp,"Can't create mailbox node %.80s: %.80s",path,strerror (errno));
+    MM_LOG (tmp,ERROR);
+  }
+  umask (mask);			/* restore mask */
+  return ret;			/* return status */
+}
+
+/* Dummy delete mailbox
+ * Accepts: mail stream
+ *	    mailbox name to delete
+ * Returns: T on success, NIL on failure
+ */
+
+long dummy_delete (MAILSTREAM *stream,char *mailbox)
+{
+  struct stat sbuf;
+  char *s,tmp[MAILTMPLEN];
+  if (!(s = dummy_file (tmp,mailbox))) {
+    sprintf (tmp,"Can't delete - invalid name: %.80s",s);
+    MM_LOG (tmp,ERROR);
+  }
+				/* no trailing / (workaround BSD kernel bug) */
+  if ((s = strrchr (tmp,'/')) && !s[1]) *s = '\0';
+  if (stat (tmp,&sbuf) || ((sbuf.st_mode & S_IFMT) == S_IFDIR) ?
+      rmdir (tmp) : unlink (tmp)) {
+    sprintf (tmp,"Can't delete mailbox %.80s: %.80s",mailbox,strerror (errno));
+    MM_LOG (tmp,ERROR);
+    return NIL;
+  }
+  return T;			/* return success */
+}
+
+/* Mail rename mailbox
+ * Accepts: mail stream
+ *	    old mailbox name
+ *	    new mailbox name
+ * Returns: T on success, NIL on failure
+ */
+
+long dummy_rename (MAILSTREAM *stream,char *old,char *newname)
+{
+  struct stat sbuf;
+  char c,*s,tmp[MAILTMPLEN],mbx[MAILTMPLEN],oldname[MAILTMPLEN];
+				/* no trailing / allowed */
+  if (!dummy_file (oldname,old) || !(s = dummy_file (mbx,newname)) ||
+      stat (oldname,&sbuf) || ((s = strrchr (s,'/')) && !s[1] &&
+			       ((sbuf.st_mode & S_IFMT) != S_IFDIR))) {
+    sprintf (mbx,"Can't rename %.80s to %.80s: invalid name",old,newname);
+    MM_LOG (mbx,ERROR);
+    return NIL;
+  }
+  if (s) {			/* found a directory delimiter? */
+    if (!s[1]) *s = '\0';	/* ignore trailing delimiter */
+    else {			/* found superior to destination name? */
+      c = *++s;			/* remember first character of inferior */
+      *s = '\0';		/* tie off to get just superior */
+				/* name doesn't exist, create it */
+      if ((stat (mbx,&sbuf) || ((sbuf.st_mode & S_IFMT) != S_IFDIR)) &&
+	  !dummy_create (stream,mbx)) return NIL;
+      *s = c;			/* restore full name */
+    }
+  }
+				/* rename of non-ex INBOX creates dest */
+  if (!compare_cstring (old,"INBOX") && stat (oldname,&sbuf))
+    return dummy_create (NIL,mbx);
+  if (rename (oldname,mbx)) {
+    sprintf (tmp,"Can't rename mailbox %.80s to %.80s: %.80s",old,newname,
+	     strerror (errno));
+    MM_LOG (tmp,ERROR);
+    return NIL;
+  }
+  return T;			/* return success */
+}
+
+/* Dummy open
+ * Accepts: stream to open
+ * Returns: stream on success, NIL on failure
+ */
+
+MAILSTREAM *dummy_open (MAILSTREAM *stream)
+{
+  int fd;
+  char err[MAILTMPLEN],tmp[MAILTMPLEN];
+  struct stat sbuf;
+				/* OP_PROTOTYPE call */
+  if (!stream) return &dummyproto;
+  err[0] = '\0';		/* no error message yet */
+				/* can we open the file? */
+  if (!dummy_file (tmp,stream->mailbox))
+    sprintf (err,"Can't open this name: %.80s",stream->mailbox);
+  else if ((fd = open (tmp,O_RDONLY,NIL)) < 0) {
+				/* no, error unless INBOX */
+    if (compare_cstring (stream->mailbox,"INBOX"))
+      sprintf (err,"%.80s: %.80s",strerror (errno),stream->mailbox);
+  }
+  else {			/* file had better be empty then */
+    fstat (fd,&sbuf);		/* sniff at its size */
+    close (fd);
+    if ((sbuf.st_mode & S_IFMT) != S_IFREG)
+      sprintf (err,"Can't open %.80s: not a selectable mailbox",
+	       stream->mailbox);
+    else if (sbuf.st_size)	/* bogus format if non-empty */
+      sprintf (err,"Can't open %.80s (file %.80s): not in valid mailbox format",
+	       stream->mailbox,tmp);
+  }
+  if (err[0]) {			/* if an error happened */
+    MM_LOG (err,stream->silent ? WARN : ERROR);
+    return NIL;
+  }
+  else if (!stream->silent) {	/* only if silence not requested */
+    mail_exists (stream,0);	/* say there are 0 messages */
+    mail_recent (stream,0);	/* and certainly no recent ones! */
+    stream->uid_validity = time (0);
+  }
+  stream->inbox = T;		/* note that it's an INBOX */
+  return stream;		/* return success */
+}
+
+
+/* Dummy close
+ * Accepts: MAIL stream
+ *	    options
+ */
+
+void dummy_close (MAILSTREAM *stream,long options)
+{
+				/* return silently */
+}
+
+/* Dummy ping mailbox
+ * Accepts: MAIL stream
+ * Returns: T if stream alive, else NIL
+ */
+
+long dummy_ping (MAILSTREAM *stream)
+{
+  MAILSTREAM *test;
+  if (time (0) >=		/* time to do another test? */
+      ((time_t) (stream->gensym +
+		 (long) mail_parameters (NIL,GET_SNARFINTERVAL,NIL)))) {
+				/* has mailbox format changed? */
+    if ((test = mail_open (NIL,stream->mailbox,OP_PROTOTYPE)) &&
+	(test->dtb != stream->dtb) &&
+	(test = mail_open (NIL,stream->mailbox,NIL))) {
+				/* preserve some resources */
+      test->original_mailbox = stream->original_mailbox;
+      stream->original_mailbox = NIL;
+      test->sparep = stream->sparep;
+      stream->sparep = NIL;
+      test->sequence = stream->sequence;
+      mail_close ((MAILSTREAM *) /* flush resources used by dummy stream */
+		  memcpy (fs_get (sizeof (MAILSTREAM)),stream,
+			  sizeof (MAILSTREAM)));
+				/* swap the streams */
+      memcpy (stream,test,sizeof (MAILSTREAM));
+      fs_give ((void **) &test);/* flush test now that copied */
+				/* make sure application knows */
+      mail_exists (stream,stream->recent = stream->nmsgs);
+    }
+				/* still hasn't changed */
+    else stream->gensym = time (0);
+  }
+  return T;
+}
+
+
+/* Dummy check mailbox
+ * Accepts: MAIL stream
+ * No-op for readonly files, since read/writer can expunge it from under us!
+ */
+
+void dummy_check (MAILSTREAM *stream)
+{
+  dummy_ping (stream);		/* invoke ping */
+}
+
+
+/* Dummy expunge mailbox
+ * Accepts: MAIL stream
+ *	    sequence to expunge if non-NIL
+ *	    expunge options
+ * Returns: T, always
+ */
+
+long dummy_expunge (MAILSTREAM *stream,char *sequence,long options)
+{
+  return LONGT;
+}
+
+/* Dummy copy message(s)
+ * Accepts: MAIL stream
+ *	    sequence
+ *	    destination mailbox
+ *	    options
+ * Returns: T if copy successful, else NIL
+ */
+
+long dummy_copy (MAILSTREAM *stream,char *sequence,char *mailbox,long options)
+{
+  if ((options & CP_UID) ? mail_uid_sequence (stream,sequence) :
+      mail_sequence (stream,sequence)) fatal ("Impossible dummy_copy");
+  return NIL;
+}
+
+
+/* Dummy append message string
+ * Accepts: mail stream
+ *	    destination mailbox
+ *	    append callback function
+ *	    data for callback
+ * Returns: T on success, NIL on failure
+ */
+
+long dummy_append (MAILSTREAM *stream,char *mailbox,append_t af,void *data)
+{
+  struct stat sbuf;
+  int fd = -1;
+  int e;
+  char tmp[MAILTMPLEN];
+  MAILSTREAM *ts = default_proto (T);
+				/* append to INBOX? */
+  if (!compare_cstring (mailbox,"INBOX")) {
+				/* yes, if no empty proto try creating */
+    if (!ts && !(*(ts = default_proto (NIL))->dtb->create) (ts,"INBOX"))
+      ts = NIL;
+  }
+  else if (dummy_file (tmp,mailbox) && ((fd = open (tmp,O_RDONLY,NIL)) < 0)) {
+    if ((e = errno) == ENOENT) /* failed, was it no such file? */
+      MM_NOTIFY (stream,"[TRYCREATE] Must create mailbox before append",NIL);
+    sprintf (tmp,"%.80s: %.80s",strerror (e),mailbox);
+    MM_LOG (tmp,ERROR);		/* pass up error */
+    return NIL;			/* always fails */
+  }
+  else if (fd >= 0) {		/* found file? */
+    fstat (fd,&sbuf);		/* get its size */
+    close (fd);			/* toss out the fd */
+    if (sbuf.st_size) ts = NIL; /* non-empty file? */
+  }
+  if (ts) return (*ts->dtb->append) (stream,mailbox,af,data);
+  sprintf (tmp,"Indeterminate mailbox format: %.80s",mailbox);
+  MM_LOG (tmp,ERROR);
+  return NIL;
+}
+
+/* Dummy mail generate file string
+ * Accepts: temporary buffer to write into
+ *	    mailbox name string
+ * Returns: local file string or NIL if failure
+ */
+
+char *dummy_file (char *dst,char *name)
+{
+  char *s = mailboxfile (dst,name);
+				/* return our standard inbox */
+  return (s && !*s) ? strcpy (dst,sysinbox ()) : s;
+}
+
+
+/* Dummy canonicalize name
+ * Accepts: buffer to write name
+ *	    reference
+ *	    pattern
+ * Returns: T if success, NIL if failure
+ */
+
+long dummy_canonicalize (char *tmp,char *ref,char *pat)
+{
+  unsigned long i;
+  char *s;
+  if (ref) {			/* preliminary reference check */
+    if (*ref == '{') return NIL;/* remote reference not allowed */
+    else if (!*ref) ref = NIL;	/* treat empty reference as no reference */
+  }
+  switch (*pat) {
+  case '#':			/* namespace name */
+    if (mailboxfile (tmp,pat)) strcpy (tmp,pat);
+    else return NIL;		/* unknown namespace */
+    break;
+  case '{':			/* remote names not allowed */
+    return NIL;
+  case '/':			/* rooted name */
+  case '~':			/* home directory name */
+    if (!ref || (*ref != '#')) {/* non-namespace reference? */
+      strcpy (tmp,pat);		/* yes, ignore */
+      break;
+    }
+				/* fall through */
+  default:			/* apply reference for all other names */
+    if (!ref) strcpy (tmp,pat);	/* just copy if no namespace */
+    else if ((*ref != '#') || mailboxfile (tmp,ref)) {
+				/* wants root of name? */
+      if (*pat == '/') strcpy (strchr (strcpy (tmp,ref),'/'),pat);
+				/* otherwise just append */
+      else sprintf (tmp,"%s%s",ref,pat);
+    }
+    else return NIL;		/* unknown namespace */
+  }
+				/* count wildcards */
+  for (i = 0, s = tmp; *s; *s++) if ((*s == '*') || (*s == '%')) ++i;
+  if (i > MAXWILDCARDS) {	/* ridiculous wildcarding? */
+    MM_LOG ("Excessive wildcards in LIST/LSUB",ERROR);
+    return NIL;
+  }
+  return T;
+}