{
{   The purpose of this request is to prepare a local file for access.
{ Functions as described for amp$open are performed.  These functions include
{ validation of access to a file, allowing segment or record access to a file,
{ and specification of attributes for a file.
{
{       BAP$OPEN (LOCAL_FILE_NAME, ACCESS_LEVEL, ACCESS_SELECTIONS,
{         FILE_PREVIOUSLY_OPENED, CONTAINS_DATA, FILE_IDENTIFIER, WORK_RESULT,
{         EVALUATED_FILE_REFERENCE, STATUS)
{
{ LOCAL_FILE_NAME: (input)  This parameter specifies the local file name.
{
{ ACCESS_LEVEL: (input)  This parameter specifies the means by which this file
{       will be accessed.
{
{ ACCESS_SELECTIONS: (input)  This parameter specifies one or more temporary or
{       structural attribute values to describe the file and the manner of file
{       access.
{
{ FILE_PREVIOUSLY_OPENED: (output)  This parameter returns whether the file had
{       ever previously been opened.
{
{ CONTAINS_DATA: (output)  This parameter indicates whether there has been any
{       data written to the file (that is, is EOI > 0?).
{
{ FILE_IDENTIFIER: (output)  This parameter specifies the file access
{       identifier which is assigned to this instance of open for the file.
{
{ WORK_RESULT NOT CURRENTLY SUPPORTED
{ WORK_RESULT: (output) This parameter returns whether the open resulted
{       in an implicit permanent file creation, implicit permanent file
{       attachment, or merely a local file create.
{       BAC$FILE_NOT_CREATED.  No new file was created as a result of this
{         request.
{       BAC$IMPLICIT_PF_CREATE. A permanent file was created as a result
{         of the open.
{       BAC$IMPLICIT_PF_ATTACH. A permanent file was attached as a result
{         of the open.
{       BAC$TEMPORARY_FILE_CREATE. A temporary file was created as a result
{         of the open.
{
{ EVALUATED_FILE_REFERENCE: (output)  This parameter specifies the file
{       reference of the file which has been opened.
{
{ STATUS: (output) This parameter specifies the request status.
{
