* Clean up some function definitions to comply with strict

[alpine.git] / imap / src / osdep / amiga / mh.c

/* ========================================================================
 * Copyright 2008-2011 Mark Crispin
 * ========================================================================
 */

/*
 * Program:     MH mail routines
 *
 * Author(s):   Mark Crispin
 *
 * Date:        23 February 1992
 * Last Edited: 8 April 2011
 *
 * Previous versions of this file were
 *
 * 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
 *
 */


#include <stdio.h>
#include <ctype.h>
#include <errno.h>
#ifndef errno
extern int errno;               /* just in case */
#endif
#include "mail.h"
#include "osdep.h"
#include <pwd.h>
#include <sys/stat.h>
#include <sys/time.h>
#include "misc.h"
#include "dummy.h"
#include "fdstring.h"


/* Build parameters */

#define MHINBOX "#mhinbox"      /* corresponds to namespace in env_unix.c */
#define MHINBOXDIR "inbox"
#define MHPROFILE ".mh_profile"
#define MHCOMMA ','
#define MHSEQUENCE ".mh_sequence"
#define MHSEQUENCES ".mh_sequences"
#define MHPATH "Mail"


/* mh_load_message() flags */

#define MLM_HEADER 0x1          /* load message text */
#define MLM_TEXT 0x2            /* load message text */
\f
/* MH I/O stream local data */
        
typedef struct mh_local {
  char *dir;                    /* spool directory name */
  unsigned char buf[CHUNKSIZE]; /* temporary buffer */
  unsigned long cachedtexts;    /* total size of all cached texts */
  time_t scantime;              /* last time directory scanned */
} MHLOCAL;


/* Convenient access to local data */

#define LOCAL ((MHLOCAL *) stream->local)


/* Function prototypes */

DRIVER *mh_valid (char *name);
int mh_isvalid (char *name,char *tmp,long synonly);
int mh_namevalid (char *name);
char *mh_path (char *tmp);
void *mh_parameters (long function,void *value);
long mh_dirfmttest (char *name);
void mh_scan (MAILSTREAM *stream,char *ref,char *pat,char *contents);
void mh_list (MAILSTREAM *stream,char *ref,char *pat);
void mh_lsub (MAILSTREAM *stream,char *ref,char *pat);
void mh_list_work (MAILSTREAM *stream,char *dir,char *pat,long level);
long mh_subscribe (MAILSTREAM *stream,char *mailbox);
long mh_unsubscribe (MAILSTREAM *stream,char *mailbox);
long mh_create (MAILSTREAM *stream,char *mailbox);
long mh_delete (MAILSTREAM *stream,char *mailbox);
long mh_rename (MAILSTREAM *stream,char *old,char *newname);
MAILSTREAM *mh_open (MAILSTREAM *stream);
void mh_close (MAILSTREAM *stream,long options);
void mh_fast (MAILSTREAM *stream,char *sequence,long flags);
void mh_load_message (MAILSTREAM *stream,unsigned long msgno,long flags);
char *mh_header (MAILSTREAM *stream,unsigned long msgno,unsigned long *length,
                 long flags);
long mh_text (MAILSTREAM *stream,unsigned long msgno,STRING *bs,long flags);
long mh_ping (MAILSTREAM *stream);
void mh_check (MAILSTREAM *stream);
long mh_expunge (MAILSTREAM *stream,char *sequence,long options);
long mh_copy (MAILSTREAM *stream,char *sequence,char *mailbox,
              long options);
long mh_append (MAILSTREAM *stream,char *mailbox,append_t af,void *data);

int mh_select (struct direct *name);
int mh_numsort (const void *d1,const void *d2);
char *mh_file (char *dst,char *name);
long mh_canonicalize (char *pattern,char *ref,char *pat);
void mh_setdate (char *file,MESSAGECACHE *elt);
\f
/* MH mail routines */


/* Driver dispatch used by MAIL */

DRIVER mhdriver = {
  "mh",                         /* driver name */
                                /* driver flags */
  DR_MAIL|DR_LOCAL|DR_NOFAST|DR_NAMESPACE|DR_NOSTICKY|DR_DIRFMT,
  (DRIVER *) NIL,               /* next driver */
  mh_valid,                     /* mailbox is valid for us */
  mh_parameters,                /* manipulate parameters */
  mh_scan,                      /* scan mailboxes */
  mh_list,                      /* find mailboxes */
  mh_lsub,                      /* find subscribed mailboxes */
  mh_subscribe,                 /* subscribe to mailbox */
  mh_unsubscribe,               /* unsubscribe from mailbox */
  mh_create,                    /* create mailbox */
  mh_delete,                    /* delete mailbox */
  mh_rename,                    /* rename mailbox */
  mail_status_default,          /* status of mailbox */
  mh_open,                      /* open mailbox */
  mh_close,                     /* close mailbox */
  mh_fast,                      /* fetch message "fast" attributes */
  NIL,                          /* fetch message flags */
  NIL,                          /* fetch overview */
  NIL,                          /* fetch message envelopes */
  mh_header,                    /* fetch message header */
  mh_text,                      /* fetch message body */
  NIL,                          /* fetch partial message text */
  NIL,                          /* unique identifier */
  NIL,                          /* message number */
  NIL,                          /* modify flags */
  NIL,                          /* per-message modify flags */
  NIL,                          /* search for message based on criteria */
  NIL,                          /* sort messages */
  NIL,                          /* thread messages */
  mh_ping,                      /* ping mailbox to see if still alive */
  mh_check,                     /* check for new messages */
  mh_expunge,                   /* expunge deleted messages */
  mh_copy,                      /* copy messages to another mailbox */
  mh_append,                    /* append string message to mailbox */
  NIL                           /* garbage collect stream */
};

                                /* prototype stream */
MAILSTREAM mhproto = {&mhdriver};


static char *mh_profile = NIL;  /* holds MH profile */
static char *mh_pathname = NIL; /* holds MH path name */
static long mh_once = 0;        /* already snarled once */
static long mh_allow_inbox =NIL;/* allow INBOX as well as MHINBOX */
\f
/* MH mail validate mailbox
 * Accepts: mailbox name
 * Returns: our driver if name is valid, NIL otherwise
 */

DRIVER *mh_valid (char *name)
{
  char tmp[MAILTMPLEN];
  return mh_isvalid (name,tmp,T) ? &mhdriver : NIL;
}


/* MH mail test for valid mailbox
 * Accepts: mailbox name
 *          temporary buffer to use
 *          syntax only test flag
 * Returns: T if valid, NIL otherwise
 */

int mh_isvalid (char *name,char *tmp,long synonly)
{
  struct stat sbuf;
  char *s,*t,altname[MAILTMPLEN];
  unsigned long i;
  int ret = NIL;
  errno = NIL;                  /* zap any error condition */
                                /* mh name? */
  if ((mh_allow_inbox && !compare_cstring (name,"INBOX")) ||
      !compare_cstring (name,MHINBOX) ||
      ((name[0] == '#') && ((name[1] == 'm') || (name[1] == 'M')) &&
       ((name[2] == 'h') || (name[2] == 'H')) && (name[3] == '/') && name[4])){
    if (mh_path (tmp))          /* validate name if INBOX or not synonly */
      ret = (synonly && compare_cstring (name,"INBOX")) ?
        T : ((stat (mh_file (tmp,name),&sbuf) == 0) &&
             (sbuf.st_mode & S_IFMT) == S_IFDIR);
    else if (!mh_once++) {      /* only report error once */
      sprintf (tmp,"%.900s not found, mh format names disabled",mh_profile);
      mm_log (tmp,WARN);
    }
  }
                                /* see if non-NS name within mh hierarchy */
  else if ((name[0] != '#') && (s = mh_path (tmp)) && (i = strlen (s)) &&
           (t = mailboxfile (tmp,name)) && !strncmp (t,s,i) &&
           (tmp[i] == '/') && tmp[i+1]) {
    sprintf (altname,"#mh%.900s",tmp+i);
                                /* can't do synonly here! */
    ret = mh_isvalid (altname,tmp,NIL);
  }
  else errno = EINVAL;          /* bogus name */
  return ret;
}
\f
/* MH mail test for valid mailbox
 * Accepts: mailbox name
 * Returns: T if valid, NIL otherwise
 */

int mh_namevalid (char *name)
{
  char *s;
  if (name[0] == '#' && (name[1] == 'm' || name[1] == 'M') &&
      (name[2] == 'h' || name[2] == 'H') && name[3] == '/')
    for (s = name; s && *s;) {  /* make sure no all-digit nodes */
      if (isdigit (*s)) s++;    /* digit, check this node further... */
      else if (*s == '/') break;/* all digit node, barf */
                                /* non-digit, skip to next node or return */
      else if (!((s = strchr (s+1,'/')) && *++s)) return T;
    }
  return NIL;                   /* all numeric or empty node */
}
\f
/* Return MH path
 * Accepts: temporary buffer
 * Returns: MH path or NIL if MH disabled
 */

char *mh_path (char *tmp)
{
  char *s,*t,*v,*r;
  int fd;
  struct stat sbuf;
  if (!mh_profile) {            /* build mh_profile and mh_pathname now */
    sprintf (tmp,"%s/%s",myhomedir (),MHPROFILE);
    if ((fd = open (mh_profile = cpystr (tmp),O_RDONLY,NIL)) >= 0) {
      fstat (fd,&sbuf);         /* yes, get size and read file */
      read (fd,(t = (char *) fs_get (sbuf.st_size + 1)),sbuf.st_size);
      close (fd);               /* don't need the file any more */
      t[sbuf.st_size] = '\0';   /* tie it off */
                                /* parse profile file */
      for (s = strtok_r (t,"\r\n",&r); s && *s; s = strtok_r (NIL,"\r\n",&r)) {
                                /* found space in line? */
        if (v = strpbrk (s," \t")) {
          *v++ = '\0';          /* tie off, is keyword "Path:"? */
          if (!compare_cstring (s,"Path:")) {
                                /* skip whitespace */
            while ((*v == ' ') || (*v == '\t')) ++v;
                                /* absolute path? */
            if (*v == '/') s = v;
            else sprintf (s = tmp,"%s/%s",myhomedir (),v);
                                /* copy name */
            mh_pathname = cpystr (s);
            break;              /* don't need to look at rest of file */
          }
        }
      }
      fs_give ((void **) &t);   /* flush profile text */
      if (!mh_pathname) {       /* default path if not in the profile */
        sprintf (tmp,"%s/%s",myhomedir (),MHPATH);
        mh_pathname = cpystr (tmp);
      }
    }
  }
  return mh_pathname;
}
\f
/* MH manipulate driver parameters
 * Accepts: function code
 *          function-dependent value
 * Returns: function-dependent return value
 */

void *mh_parameters (long function,void *value)
{
  void *ret = NIL;
  switch ((int) function) {
  case GET_INBOXPATH:
    if (value) ret = mh_file ((char *) value,"INBOX");
    break;
  case GET_DIRFMTTEST:
    ret = (void *) mh_dirfmttest;
    break;
  case SET_MHPROFILE:
    if (mh_profile) fs_give ((void **) &mh_profile);
    mh_profile = cpystr ((char *) value);
  case GET_MHPROFILE:
    ret = (void *) mh_profile;
    break;
  case SET_MHPATH:
    if (mh_pathname) fs_give ((void **) &mh_pathname);
    mh_pathname = cpystr ((char *) value);
  case GET_MHPATH:
    ret = (void *) mh_pathname;
    break;
  case SET_MHALLOWINBOX:
    mh_allow_inbox = value ? T : NIL;
  case GET_MHALLOWINBOX:
    ret = (void *) (mh_allow_inbox ? VOIDT : NIL);
  }
  return ret;
}


/* MH test for directory format internal node
 * Accepts: candidate node name
 * Returns: T if internal name, NIL otherwise
 */

long mh_dirfmttest (char *s)
{
  int c;
                                /* sequence(s) file is an internal name */
  if (strcmp (s,MHSEQUENCE) && strcmp (s,MHSEQUENCES)) {
    if (*s == MHCOMMA) ++s;     /* else comma + all numeric name */
                                /* success if all-numeric */
    while (c = *s++) if (!isdigit (c)) return NIL;
  }
  return LONGT;
}
\f
/* MH scan mailboxes
 * Accepts: mail stream
 *          reference
 *          pattern to search
 *          string to scan
 */

void mh_scan (MAILSTREAM *stream,char *ref,char *pat,char *contents)
{
  char *s,test[MAILTMPLEN],file[MAILTMPLEN];
  long i = 0;
  if (!pat || !*pat) {          /* empty pattern? */
    if (mh_canonicalize (test,ref,"*")) {
                                /* tie off name at root */
      if (s = strchr (test,'/')) *++s = '\0';
      else test[0] = '\0';
      mm_list (stream,'/',test,LATT_NOSELECT);
    }
  }
                                /* get canonical form of name */
  else if (mh_canonicalize (test,ref,pat)) {
    if (contents) {             /* maybe I'll implement this someday */
      mm_log ("Scan not valid for mh mailboxes",ERROR);
      return;
    }
    if (test[3] == '/') {       /* looking down levels? */
                                /* yes, found any wildcards? */
      if (s = strpbrk (test,"%*")) {
                                /* yes, copy name up to that point */
        strncpy (file,test+4,i = s - (test+4));
        file[i] = '\0';         /* tie off */
      }
      else strcpy (file,test+4);/* use just that name then */
                                /* find directory name */
      if (s = strrchr (file,'/')) {
        *s = '\0';              /* found, tie off at that point */
        s = file;
      }
                                /* do the work */
      mh_list_work (stream,s,test,0);
    }
                                /* always an INBOX */
    if (!compare_cstring (test,MHINBOX))
      mm_list (stream,NIL,MHINBOX,LATT_NOINFERIORS);
  }
}
\f
/* MH list mailboxes
 * Accepts: mail stream
 *          reference
 *          pattern to search
 */

void mh_list (MAILSTREAM *stream,char *ref,char *pat)
{
  mh_scan (stream,ref,pat,NIL);
}


/* MH list subscribed mailboxes
 * Accepts: mail stream
 *          reference
 *          pattern to search
 */

void mh_lsub (MAILSTREAM *stream,char *ref,char *pat)
{
  void *sdb = NIL;
  char *s,test[MAILTMPLEN],tmp[MAILTMPLEN];
                                /* get canonical form of name */
  if (mh_canonicalize (test,ref,pat) && (s = sm_read (tmp,&sdb))) {
    do if (pmatch_full (s,test,'/')) mm_lsub (stream,'/',s,NIL);
    while (s = sm_read (tmp,&sdb)); /* until no more subscriptions */
  }
}
\f
/* MH list mailboxes worker routine
 * Accepts: mail stream
 *          directory name to search
 *          search pattern
 *          search level
 */

void mh_list_work (MAILSTREAM *stream,char *dir,char *pat,long level)
{
  DIR *dp;
  struct direct *d;
  struct stat sbuf;
  char *cp,*np,curdir[MAILTMPLEN],name[MAILTMPLEN];
                                /* build MH name to search */
  if (dir) sprintf (name,"#mh/%s/",dir);
  else strcpy (name,"#mh/");
                                /* make directory name, punt if bogus */
  if (!mh_file (curdir,name)) return;
  cp = curdir + strlen (curdir);/* end of directory name */
  np = name + strlen (name);    /* end of MH name */
  if (dp = opendir (curdir)) {  /* open directory */
    while (d = readdir (dp))    /* scan, ignore . and numeric names */
      if ((d->d_name[0] != '.') && !mh_select (d)) {
        strcpy (cp,d->d_name);  /* make directory name */
        if (!stat (curdir,&sbuf) && ((sbuf.st_mode & S_IFMT) == S_IFDIR)) {
          strcpy (np,d->d_name);/* make mh name of directory name */
                                /* yes, an MH name if full match */
          if (pmatch_full (name,pat,'/')) mm_list (stream,'/',name,NIL);
                                /* check if should recurse */
          if (dmatch (name,pat,'/') &&
              (level < (long) mail_parameters (NIL,GET_LISTMAXLEVEL,NIL)))
            mh_list_work (stream,name+4,pat,level+1);
        }
      }
    closedir (dp);              /* all done, flush directory */
  }
}
\f
/* MH mail subscribe to mailbox
 * Accepts: mail stream
 *          mailbox to add to subscription list
 * Returns: T on success, NIL on failure
 */

long mh_subscribe (MAILSTREAM *stream,char *mailbox)
{
  return sm_subscribe (mailbox);
}


/* MH mail unsubscribe to mailbox
 * Accepts: mail stream
 *          mailbox to delete from subscription list
 * Returns: T on success, NIL on failure
 */

long mh_unsubscribe (MAILSTREAM *stream,char *mailbox)
{
  return sm_unsubscribe (mailbox);
}
\f
/* MH mail create mailbox
 * Accepts: mail stream
 *          mailbox name to create
 * Returns: T on success, NIL on failure
 */

long mh_create (MAILSTREAM *stream,char *mailbox)
{
  char tmp[MAILTMPLEN];
  if (!mh_namevalid (mailbox))  /* validate name */
    sprintf (tmp,"Can't create mailbox %.80s: invalid MH-format name",mailbox);
                                /* must not already exist */
  else if (mh_isvalid (mailbox,tmp,NIL))
    sprintf (tmp,"Can't create mailbox %.80s: mailbox already exists",mailbox);
  else if (!mh_path (tmp)) return NIL;
                                /* try to make it */
  else if (!(mh_file (tmp,mailbox) &&
             dummy_create_path (stream,strcat (tmp,"/"),
                                get_dir_protection (mailbox))))
    sprintf (tmp,"Can't create mailbox %.80s: %s",mailbox,strerror (errno));
  else return LONGT;            /* success */
  mm_log (tmp,ERROR);
  return NIL;
}
\f
/* 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];
                                /* 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 */
                                /* massacre all mh owned files */
    while (d = readdir (dirp)) if (mh_dirfmttest (d->d_name)) {
      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,WARN);
  }
  return T;                     /* return success */
}
\f
/* 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;
                                /* old mailbox name must be valid */
  if (!mh_isvalid (old,tmp,NIL))
    sprintf (tmp,"Can't rename mailbox %.80s: no such mailbox",old);
  else if (!mh_namevalid (newname))
    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_path (stream,tmp1,get_dir_protection (newname)))
        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;
}
\f
/* 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));
  /* INBOXness is one of the following:
   * #mhinbox (case-independent)
   * #mh/inbox (mh is case-independent, inbox is case-dependent)
   * INBOX (case-independent
   */           
  stream->inbox =               /* note if an INBOX or not */
    (!compare_cstring (stream->mailbox,MHINBOX) ||
     ((stream->mailbox[0] == '#') &&
      ((stream->mailbox[1] == 'm') || (stream->mailbox[1] == 'M')) &&
      ((stream->mailbox[2] == 'h') || (stream->mailbox[2] == 'H')) &&
      (stream->mailbox[3] == '/') && !strcmp (stream->mailbox+4,MHINBOXDIR)) ||
     !compare_cstring (stream->mailbox,"INBOX")) ? T : NIL;
  mh_file (tmp,stream->mailbox);/* get directory name */
  LOCAL->dir = cpystr (tmp);    /* copy directory name for later */
  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 */
}
\f
/* 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,NIL,NIL);
    if (LOCAL->dir) fs_give ((void **) &LOCAL->dir);
                                /* 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)
{
  MESSAGECACHE *elt;
  unsigned long i;
                                /* set up metadata for all messages */
  if (stream && LOCAL && ((flags & FT_UID) ?
                          mail_uid_sequence (stream,sequence) :
                          mail_sequence (stream,sequence)))
    for (i = 1; i <= stream->nmsgs; i++)
      if ((elt = mail_elt (stream,i))->sequence &&
          !(elt->day && elt->rfc822_size)) mh_load_message (stream,i,NIL);
}
\f
/* MH load message into cache
 * Accepts: MAIL stream
 *          message #
 *          option flags
 */

void mh_load_message (MAILSTREAM *stream,unsigned long msgno,long flags)
{
  unsigned long i,j,nlseen;
  int fd;
  unsigned char c,*t;
  struct stat sbuf;
  MESSAGECACHE *elt;
  FDDATA d;
  STRING bs;
  elt = mail_elt (stream,msgno);/* get elt */
                                /* build message file name */
  sprintf (LOCAL->buf,"%s/%lu",LOCAL->dir,elt->private.uid);
                                /* anything we need not currently cached? */
  if ((!elt->day || !elt->rfc822_size ||
       ((flags & MLM_HEADER) && !elt->private.msg.header.text.data) ||
       ((flags & MLM_TEXT) && !elt->private.msg.text.text.data)) &&
      ((fd = open (LOCAL->buf,O_RDONLY,NIL)) >= 0)) {
    fstat (fd,&sbuf);           /* get file metadata */
    d.fd = fd;                  /* set up file descriptor */
    d.pos = 0;                  /* start of file */
    d.chunk = LOCAL->buf;
    d.chunksize = CHUNKSIZE;
    INIT (&bs,fd_string,&d,sbuf.st_size);
    if (!elt->day) {            /* set internaldate to file date */
      struct tm *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;
    }
\f
    if (!elt->rfc822_size) {    /* know message size yet? */
      for (i = 0, j = SIZE (&bs), nlseen = 0; j--; ) switch (SNX (&bs)) {
      case '\015':              /* unlikely carriage return */
        if (!j || (CHR (&bs) != '\012')) {
          i++;                  /* ugh, raw CR */
          nlseen = NIL;
          break;
        }
        SNX (&bs);              /* eat the line feed, drop in */
        --j;
      case '\012':              /* line feed? */
        i += 2;                 /* count a CRLF */
                                /* header size known yet? */
        if (!elt->private.msg.header.text.size && nlseen) {
                                /* note position in file */
          elt->private.special.text.size = GETPOS (&bs);
                                /* and CRLF-adjusted size */
          elt->private.msg.header.text.size = i;
        }
        nlseen = T;             /* note newline seen */
        break;
      default:                  /* ordinary character */
        i++;
        nlseen = NIL;
        break;
      }
      SETPOS (&bs,0);           /* restore old position */
      elt->rfc822_size = i;     /* note that we have size now */
                                /* header is entire message if no delimiter */
      if (!elt->private.msg.header.text.size)
        elt->private.msg.header.text.size = elt->rfc822_size;
                                /* text is remainder of message */
      elt->private.msg.text.text.size =
        elt->rfc822_size - elt->private.msg.header.text.size;
    }
                                /* need to load cache with message data? */
    if (((flags & MLM_HEADER) && !elt->private.msg.header.text.data) ||
        ((flags & MLM_TEXT) && !elt->private.msg.text.text.data)) {
                                /* purge cache if too big */
      if (LOCAL->cachedtexts > max (stream->nmsgs * 4096,2097152)) {
                                /* just can't keep that much */
        mail_gc (stream,GC_TEXTS);
        LOCAL->cachedtexts = 0;
      }
\f
      if ((flags & MLM_HEADER) && !elt->private.msg.header.text.data) {
        t = elt->private.msg.header.text.data =
          (unsigned char *) fs_get (elt->private.msg.header.text.size + 1);
        LOCAL->cachedtexts += elt->private.msg.header.text.size;
                                /* read in message header */
        for (i = 0; i < elt->private.msg.header.text.size; i++)
          switch (c = SNX (&bs)) {
          case '\015':          /* unlikely carriage return */
            *t++ = c;
            if ((CHR (&bs) == '\012')) {
              *t++ = SNX (&bs);
              i++;
            }
            break;
          case '\012':          /* line feed? */
            *t++ = '\015';
            i++;
          default:
            *t++ = c;
            break;
          }
        *t = '\0';              /* tie off string */
        if ((t - elt->private.msg.header.text.data) !=
            elt->private.msg.header.text.size) fatal ("mh hdr size mismatch");
      }
      if ((flags & MLM_TEXT) && !elt->private.msg.text.text.data) {
        t = elt->private.msg.text.text.data =
          (unsigned char *) fs_get (elt->private.msg.text.text.size + 1);
        SETPOS (&bs,elt->private.special.text.size);
        LOCAL->cachedtexts += elt->private.msg.text.text.size;
                                /* read in message text */
        for (i = 0; i < elt->private.msg.text.text.size; i++)
          switch (c = SNX (&bs)) {
          case '\015':          /* unlikely carriage return */
            *t++ = c;
            if ((CHR (&bs) == '\012')) {
              *t++ = SNX (&bs);
              i++;
            }
            break;
          case '\012':          /* line feed? */
            *t++ = '\015';
            i++;
          default:
            *t++ = c;
            break;
          }
        *t = '\0';              /* tie off string */
        if ((t - elt->private.msg.text.text.data) !=
            elt->private.msg.text.text.size) fatal ("mh txt size mismatch");
      }
    }
    close (fd);                 /* flush message file */
  }
}
\f
/* 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)
{
  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)
    mh_load_message (stream,msgno,MLM_HEADER);
  *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)
{
  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_load_message (stream,msgno,MLM_TEXT);
    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);
  }
  INIT (bs,mail_string,elt->private.msg.text.text.data,
        elt->private.msg.text.text.size);
  return T;
}
\f
/* 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;
  unsigned long old = stream->uid_last;
  long nmsgs = stream->nmsgs;
  long recent = stream->recent;
  int silent = stream->silent;
  if (stat (LOCAL->dir,&sbuf)) {/* directory exists? */
    if (stream->inbox &&        /* no, create if INBOX */
        dummy_create_path (stream,strcat (mh_file (tmp,MHINBOX),"/"),
                           get_dir_protection ("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 */
                                /* 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);
          if (!stat (tmp,&sbuf) && (sbuf.st_atime > sbuf.st_mtime))
            elt->seen = T;
        }
      }
      fs_give ((void **) &names[i]);
    }
                                /* free directory */
    if (s = (void *) names) fs_give ((void **) &s);
  }
\f
                                /* if INBOX, snarf from system INBOX  */
  if (stream->inbox && strcmp (sysinbox (),stream->mailbox)) {
    old = stream->uid_last;
    mm_critical (stream);       /* go critical */
                                /* see if anything in system inbox */
    if (!stat (sysinbox (),&sbuf) && 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,
                         (long) mail_parameters (NIL,GET_MBXPROTECTION,NIL)))
             >= 0) &&
            (s = mail_fetchheader_full (sysibx,i,NIL,&j,FT_INTERNAL)) &&
            (write (fd,s,j) == j) &&
            (s = mail_fetchtext_full (sysibx,i,&j,FT_INTERNAL|FT_PEEK)) &&
            (write (fd,s,j) == j) && !fsync (fd) && !close (fd)) {
                                /* swell the cache */
          mail_exists (stream,++nmsgs);
          stream->uid_last =    /* create new elt, note its file number */
            (elt = mail_elt (stream,nmsgs))->private.uid = old;
          recent++;             /* bump recent count */
                                /* set up initial flags and date */
          elt->valid = elt->recent = T;
          elt->seen = selt->seen;
          elt->deleted = selt->deleted;
          elt->flagged = selt->flagged;
          elt->answered = selt->answered;
          elt->draft = selt->draft;
          elt->day = selt->day;elt->month = selt->month;elt->year = selt->year;
          elt->hours = selt->hours;elt->minutes = selt->minutes;
          elt->seconds = selt->seconds;
          elt->zhours = selt->zhours; elt->zminutes = selt->zminutes;
          elt->zoccident = selt->zoccident;
          mh_setdate (LOCAL->buf,elt);
          sprintf (tmp,"%lu",i);/* delete it from the sysinbox */
          mail_flag (sysibx,tmp,"\\Deleted",ST_SET);
        }
\f
        else {                  /* failed to snarf */
          if (fd) {             /* did it ever get opened? */
            close (fd);         /* close descriptor */
            unlink (LOCAL->buf);/* flush this file */
          }
          sprintf (tmp,"Message copy to MH mailbox failed: %.80s",
                   s,strerror (errno));
          mm_log (tmp,ERROR);
          r = 0;                /* stop the snarf in its tracks */
        }
      }
                                /* update scan time */
      if (!stat (LOCAL->dir,&sbuf)) LOCAL->scantime = sbuf.st_ctime;      
      mail_expunge (sysibx);    /* now expunge all those messages */
    }
    if (sysibx) mail_close (sysibx);
    mm_nocritical (stream);     /* release critical */
  }
  stream->silent = silent;      /* can pass up events now */
  mail_exists (stream,nmsgs);   /* notify upper level of mailbox size */
  mail_recent (stream,recent);
  return T;                     /* return that we are alive */
}
\f
/* MH mail check mailbox
 * Accepts: MAIL stream
 */

void mh_check (MAILSTREAM *stream)
{
  /* Perhaps in the future this will preserve flags */
  if (mh_ping (stream)) mm_log ("Check completed",(long) NIL);
}


/* MH mail expunge mailbox
 * Accepts: MAIL stream
 *          sequence to expunge if non-NIL
 *          expunge options
 * Returns: T, always
 */

long mh_expunge (MAILSTREAM *stream,char *sequence,long options)
{
  long ret;
  MESSAGECACHE *elt;
  unsigned long i = 1;
  unsigned long n = 0;
  unsigned long recent = stream->recent;
  if (ret = sequence ? ((options & EX_UID) ?
                        mail_uid_sequence (stream,sequence) :
                        mail_sequence (stream,sequence)) : LONGT) {
    mm_critical (stream);       /* go critical */
    while (i <= stream->nmsgs) {/* for each message */
      elt = mail_elt (stream,i);/* if deleted, need to trash it */
      if (elt->deleted && (sequence ? elt->sequence : T)) {
        sprintf (LOCAL->buf,"%s/%lu",LOCAL->dir,elt->private.uid);
        if (unlink (LOCAL->buf)) {/* try to delete the message */
          sprintf (LOCAL->buf,"Expunge of message %lu failed, aborted: %s",i,
                   strerror (errno));
          mm_log (LOCAL->buf,(long) NIL);
          break;
        }
                                /* note uncached */
        LOCAL->cachedtexts -= ((elt->private.msg.header.text.data ?
                                elt->private.msg.header.text.size : 0) +
                               (elt->private.msg.text.text.data ?
                                elt->private.msg.text.text.size : 0));
        mail_gc_msg (&elt->private.msg,GC_ENV | GC_TEXTS);
                                /* if recent, note one less recent message */
        if (elt->recent) --recent;
                                /* notify upper levels */
        mail_expunged (stream,i);
        n++;                    /* count up one more expunged message */
      }
      else i++;                 /* otherwise try next message */
    }
    if (n) {                    /* output the news if any expunged */
      sprintf (LOCAL->buf,"Expunged %lu messages",n);
      mm_log (LOCAL->buf,(long) NIL);
    }
    else mm_log ("No messages deleted, so no update needed",(long) NIL);
    mm_nocritical (stream);     /* release critical */
                                /* notify upper level of new mailbox size */
    mail_exists (stream,stream->nmsgs);
    mail_recent (stream,recent);
  }
  return ret;
}
\f
/* MH mail copy message(s)
 * Accepts: MAIL stream
 *          sequence
 *          destination mailbox
 *          copy options
 * Returns: T if copy successful, else NIL
 */

long mh_copy (MAILSTREAM *stream,char *sequence,char *mailbox,long options)
{
  FDDATA d;
  STRING st;
  MESSAGECACHE *elt;
  struct stat sbuf;
  int fd;
  unsigned long i;
  char flags[MAILTMPLEN],date[MAILTMPLEN];
  appenduid_t au = (appenduid_t) mail_parameters (NIL,GET_APPENDUID,NIL);
  long ret = NIL;
                                /* copy the messages */
  if ((options & CP_UID) ? mail_uid_sequence (stream,sequence) :
      mail_sequence (stream,sequence))
    for (i = 1; i <= stream->nmsgs; i++) 
      if ((elt = mail_elt (stream,i))->sequence) {
        sprintf (LOCAL->buf,"%s/%lu",LOCAL->dir,elt->private.uid);
        if ((fd = open (LOCAL->buf,O_RDONLY,NIL)) < 0) return NIL;
        fstat (fd,&sbuf);       /* get size of message */
        if (!elt->day) {        /* set internaldate to file date if needed */
          struct tm *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;
        }
        d.fd = fd;              /* set up file descriptor */
        d.pos = 0;              /* start of file */
        d.chunk = LOCAL->buf;
        d.chunksize = CHUNKSIZE;
                                /* kludge; mh_append would just strip CRs */
        INIT (&st,fd_string,&d,sbuf.st_size);
                                /* init flag string */
        flags[0] = flags[1] = '\0';
        if (elt->seen) strcat (flags," \\Seen");
        if (elt->deleted) strcat (flags," \\Deleted");
        if (elt->flagged) strcat (flags," \\Flagged");
        if (elt->answered) strcat (flags," \\Answered");
        if (elt->draft) strcat (flags," \\Draft");
        flags[0] = '(';         /* open list */
        strcat (flags,")");     /* close list */
        mail_date (date,elt);   /* generate internal date */
        if (au) mail_parameters (NIL,SET_APPENDUID,NIL);
        if ((ret = mail_append_full (NIL,mailbox,flags,date,&st)) &&
            (options & CP_MOVE)) elt->deleted = T;
        if (au) mail_parameters (NIL,SET_APPENDUID,(void *) au);
        close (fd);
      }
  if (ret && mail_parameters (NIL,GET_COPYUID,NIL))
    mm_log ("Can not return meaningful COPYUID with this mailbox format",WARN);
  return ret;                   /* return success */
}
\f
/* MH mail append message from stringstruct
 * Accepts: MAIL stream
 *          destination mailbox
 *          append callback
 *          data for callback
 * Returns: T if append successful, else NIL
 */

long mh_append (MAILSTREAM *stream,char *mailbox,append_t af,void *data)
{
  struct direct **names = NIL;
  int fd;
  char c,*flags,*date,*s,tmp[MAILTMPLEN];
  STRING *message;
  MESSAGECACHE elt;
  FILE *df;
  long i,size,last,nfiles;
  long ret = LONGT;
                                /* default stream to prototype */
  if (!stream) stream = &mhproto;
                                /* make sure valid mailbox */
  if (!mh_isvalid (mailbox,tmp,NIL)) switch (errno) {
  case ENOENT:                  /* no such file? */
    if (!((!compare_cstring (mailbox,MHINBOX) ||
           !compare_cstring (mailbox,"INBOX")) &&
          (mh_file (tmp,MHINBOX) &&
           dummy_create_path (stream,strcat (tmp,"/"),
                              get_dir_protection (mailbox))))) {
      mm_notify (stream,"[TRYCREATE] Must create mailbox before append",NIL);
      return NIL;
    }
                                /* falls through */
  case 0:                       /* merely empty file? */
    break;
  case EINVAL:
    sprintf (tmp,"Invalid MH-format mailbox name: %.80s",mailbox);
    mm_log (tmp,ERROR);
    return NIL;
  default:
    sprintf (tmp,"Not a MH-format mailbox: %.80s",mailbox);
    mm_log (tmp,ERROR);
    return NIL;
  }
                                /* get first message */
  if (!(*af) (stream,data,&flags,&date,&message)) return NIL;
  if ((nfiles = scandir (tmp,&names,mh_select,mh_numsort)) > 0) {
                                /* largest number */
    last = atoi (names[nfiles-1]->d_name);    
    for (i = 0; i < nfiles; ++i) /* free directory */
      fs_give ((void **) &names[i]);
  }
  else last = 0;                /* no messages here yet */
  if (s = (void *) names) fs_give ((void **) &s);
\f
  mm_critical (stream);         /* go critical */
  do {
    if (!SIZE (message)) {      /* guard against zero-length */
      mm_log ("Append of zero-length message",ERROR);
      ret = NIL;
      break;
    }
    if (date) {                 /* want to preserve date? */
                                /* yes, parse date into an elt */
      if (!mail_parse_date (&elt,date)) {
        sprintf (tmp,"Bad date in append: %.80s",date);
        mm_log (tmp,ERROR);
        ret = NIL;
        break;
      }
    }
    mh_file (tmp,mailbox);      /* build file name we will use */
    sprintf (tmp + strlen (tmp),"/%ld",++last);
    if (((fd = open (tmp,O_WRONLY|O_CREAT|O_EXCL,
                     (long)mail_parameters (NIL,GET_MBXPROTECTION,NIL))) < 0)||
        !(df = fdopen (fd,"ab"))) {
      sprintf (tmp,"Can't open append message: %s",strerror (errno));
      mm_log (tmp,ERROR);
      ret = NIL;
      break;
    }
                                /* copy the data w/o CR's */
    for (size = 0,i = SIZE (message); i && ret; --i)
      if (((c = SNX (message)) != '\015') && (putc (c,df) == EOF)) ret = NIL;
                                /* close the file */
    if (!ret || fclose (df)) {
      unlink (tmp);             /* delete message */
      sprintf (tmp,"Message append failed: %s",strerror (errno));
      mm_log (tmp,ERROR);
      ret = NIL;
    }
    if (ret) {                  /* set the date for this message */
      if (date) mh_setdate (tmp,&elt);
                                /* get next message */
      if (!(*af) (stream,data,&flags,&date,&message)) ret = NIL;
    }
  } while (ret && message);
  mm_nocritical (stream);       /* release critical */
  if (ret && mail_parameters (NIL,GET_APPENDUID,NIL))
    mm_log ("Can not return meaningful APPENDUID with this mailbox format",
            WARN);
  return ret;
}
\f
/* Internal routines */


/* MH file name selection test
 * Accepts: candidate directory entry
 * Returns: T to use file name, NIL to skip it
 */

int mh_select (struct direct *name)
{
  char c;
  char *s = name->d_name;
  while (c = *s++) if (!isdigit (c)) return NIL;
  return T;
}


/* MH file name comparison
 * Accepts: first candidate directory entry
 *          second candidate directory entry
 * Returns: negative if d1 < d2, 0 if d1 == d2, positive if d1 > d2
 */

int mh_numsort (const void *d1,const void *d2)
{
  return atoi ((*(struct direct **) d1)->d_name) -
    atoi ((*(struct direct **) d2)->d_name);
}


/* MH mail build file name
 * Accepts: destination string
 *          source
 * Returns: destination
 */

char *mh_file (char *dst,char *name)
{
  char *s;
  char *path = mh_path (dst);
  if (!path) fatal ("No mh path in mh_file()!");
                                /* INBOX becomes "inbox" in the MH path */
  if (!compare_cstring (name,MHINBOX) || !compare_cstring (name,"INBOX"))
    sprintf (dst,"%.900s/%.80s",path,MHINBOXDIR);
                                /* #mh names skip past prefix */
  else if (*name == '#') sprintf (dst,"%.100s/%.900s",path,name + 4);
  else mailboxfile (dst,name);  /* all other names */
                                /* tie off unnecessary trailing / */
  if ((s = strrchr (dst,'/')) && !s[1] && (s[-1] == '/')) *s = '\0';
  return dst;
}
\f
/* MH canonicalize name
 * Accepts: buffer to write name
 *          reference
 *          pattern
 * Returns: T if success, NIL if failure
 */

long mh_canonicalize (char *pattern,char *ref,char *pat)
{
  unsigned long i;
  char *s,tmp[MAILTMPLEN];
  if (ref && *ref) {            /* have a reference */
    strcpy (pattern,ref);       /* copy reference to pattern */
                                /* # overrides mailbox field in reference */
    if (*pat == '#') strcpy (pattern,pat);
                                /* pattern starts, reference ends, with / */
    else if ((*pat == '/') && (pattern[strlen (pattern) - 1] == '/'))
      strcat (pattern,pat + 1); /* append, omitting one of the period */
    else strcat (pattern,pat);  /* anything else is just appended */
  }
  else strcpy (pattern,pat);    /* just have basic name */
  if (mh_isvalid (pattern,tmp,T)) {
                                /* count wildcards */
    for (i = 0, s = pattern; *s; *s++) if ((*s == '*') || (*s == '%')) ++i;
                                /* success if not too many */
    if (i <= MAXWILDCARDS) return LONGT;
    mm_log ("Excessive wildcards in LIST/LSUB",ERROR);
  }
  return NIL;
}
\f
/* Set date for message
 * Accepts: file name
 *          elt containing date
 */

void mh_setdate (char *file,MESSAGECACHE *elt)
{
  time_t tp[2];
  tp[0] = time (0);             /* atime is now */
  tp[1] = mail_longdate (elt);  /* modification time */
  utime (file,tp);              /* set the times */
}