SQLite

** The zFilename argument is the filename pointer passed into the xOpen()
** method of a VFS implementation.  The zParam argument is the name of the
** query parameter we seek.  This routine returns the value of the zParam
** parameter if it exists.  If the parameter does not exist, this routine
** returns a NULL pointer.
*/
const char *sqlite3_uri_parameter(const char *zFilename, const char *zParam){
  if( zFilename==0 ) return 0;
  zFilename += sqlite3Strlen30(zFilename) + 1;
  while( zFilename[0] ){
    int x = strcmp(zFilename, zParam);
    zFilename += sqlite3Strlen30(zFilename) + 1;
    if( x==0 ) return zFilename;
    zFilename += sqlite3Strlen30(zFilename) + 1;
  }
  return 0;
}

/*
** Return a boolean value for a query parameter.
*/
int sqlite3_uri_boolean(const char *zFilename, const char *zParam, int bDflt){
  const char *z = sqlite3_uri_parameter(zFilename, zParam);
  return z ? sqlite3GetBoolean(z) : (bDflt!=0);
}

/*
** Return a 64-bit integer value for a query parameter.
*/
sqlite3_int64 sqlite3_uri_int64(
  const char *zFilename,    /* Filename as passed to xOpen */
  const char *zParam,       /* URI parameter sought */
  sqlite3_int64 bDflt       /* return if parameter is missing */
){
  const char *z = sqlite3_uri_parameter(zFilename, zParam);
  sqlite3_int64 v;
  if( z && sqlite3Atoi64(z, &v, sqlite3Strlen30(z), SQLITE_UTF8)==SQLITE_OK ){
    bDflt = v;
  }
  return bDflt;
}

/*
** Return the filename of the database associated with a database
** connection.
*/
const char *sqlite3_db_filename(sqlite3 *db, const char *zDbName){
  int i;

    pShmNode->mutex = sqlite3_mutex_alloc(SQLITE_MUTEX_FAST);
    if( pShmNode->mutex==0 ){
      rc = SQLITE_NOMEM;
      goto shm_open_err;
    }

    if( pInode->bProcessLock==0 ){

      int openFlags = O_RDWR | O_CREAT;
      if( sqlite3_uri_boolean(pDbFd->zPath, "readonly_shm", 0) ){

        openFlags = O_RDONLY;
        pShmNode->isReadonly = 1;
      }
      pShmNode->h = robust_open(zShmFilename, openFlags, (sStat.st_mode&0777));
      if( pShmNode->h<0 ){
        if( pShmNode->h<0 ){
          rc = unixLogError(SQLITE_CANTOPEN_BKPT, "open", zShmFilename);

  int flags,              /* Flags */
  const char *zVfs        /* Name of VFS module to use */
);

/*
** CAPI3REF: Obtain Values For URI Parameters
**
** These are utility routines, useful to VFS implementations, that check
** to see if a database file was a URI that contained a specific query 
** parameter, and if so obtains the value of that query parameter.
**
** If F is the filename pointer passed into the xOpen() method of a VFS
** implementation and P is the name of the query parameter, then
** sqlite3_uri_parameter(F,P) returns the value of the P
** parameter if it exists or a NULL pointer if P does not appear as a 
** query parameter on F.  If P is a query parameter of F
** has no explicit value, then sqlite3_uri_parameter(F,P) returns
** a pointer to an empty string.
**
** The sqlite3_uri_boolean(F,P,B) routine assumes that P is a boolean
** parameter and returns true (1) or false (0) according to the value
** of P.  The value of P is true if it is "yes" or "true" or "on" or 
** a non-zero number and is false otherwise.  If P is not a query parameter
** on F then sqlite3_uri_boolean(F,P,B) returns (B!=0).
**
** The sqlite3_uri_int64(F,P,D) routine converts the value of P into a
** 64-bit signed integer and returns that integer, or D if P does not
** exist.  If the value of P is something other than an integer, then
** zero is returned.
** 
** If F is a NULL pointer, then sqlite3_uri_parameter(F,P) returns NULL and
** sqlite3_uri_boolean(F,P,B) returns B.  If F is not a NULL pointer and
** is not a pathname pointer that SQLite passed into the xOpen VFS method,
** then the behavior of this routine is undefined and probably undesirable.
*/
const char *sqlite3_uri_parameter(const char *zFilename, const char *zParam);
int sqlite3_uri_boolean(const char *zFile, const char *zParam, int bDefault);
sqlite3_int64 sqlite3_uri_int64(const char*, const char*, sqlite3_int64);


/*
** CAPI3REF: Error Codes And Messages
**
** ^The sqlite3_errcode() interface returns the numeric [result code] or
** [extended result code] for the most recent failed sqlite3_* API call

  }

  if( rc==SQLITE_OK ){
    /* assign pointers to extra space allocated */
    memset(pGroup, 0, sz);
    pMultiplexOpen->pGroup = pGroup;
    pGroup->bEnabled = -1;
    pGroup->bTruncate = sqlite3_uri_boolean(zName, "truncate", 
                                 (flags & SQLITE_OPEN_MAIN_DB)==0);
    pGroup->szChunk = sqlite3_uri_int64(zName, "chunksize",
                                        SQLITE_MULTIPLEX_CHUNK_SIZE);
    pGroup->szChunk = (pGroup->szChunk+0xffff)&~0xffff;
    if( zName ){
      char *p = (char *)&pGroup[1];


















      pGroup->zName = p;
      memcpy(pGroup->zName, zName, nName+1);
      pGroup->nName = nName;
    }
    if( pGroup->bEnabled ){
      /* Make sure that the chunksize is such that the pending byte does not
      ** falls at the end of a chunk.  A region of up to 64K following
      ** the pending byte is never written, so if the pending byte occurs
      ** near the end of a chunk, that chunk will be too small. */
      extern int sqlite3PendingByte;
      while( (sqlite3PendingByte % pGroup->szChunk)>=(pGroup->szChunk-65536) ){
        pGroup->szChunk += 65536;
      }

**     test.db-journal    =>   test.nal
**     test.db-wal        =>   test.wal
**     test.db-shm        =>   test.shm
**     test.db-mj7f3319fa =>   test.9fa
*/
void sqlite3FileSuffix3(const char *zBaseFilename, char *z){
#if SQLITE_ENABLE_8_3_NAMES<2

  if( sqlite3_uri_boolean(zBaseFilename, "8_3_names") )

#endif
  {
    int i, sz;
    sz = sqlite3Strlen30(z);
    for(i=sz-1; i>0 && z[i]!='/' && z[i]!='.'; i--){}
    if( z[i]=='.' && ALWAYS(sz>i+4) ) memmove(&z[i+1], &z[sz-3], 4);
  }