{
{   The purpose of this request is to assign mass storage space to a file.
{ This request may only be issued by a user who has pfc$append permission}
{ for local_file_name. This request is optional since the system will}
{ dynamically assign space as the file is written. This request is intended}
{ for a user who for performance reasons wishes to pre-allocate space on one}
{ or more mass storage volumes prior to accessing the file.}
{ This request may also be used to expand an existing file.}
{   The rmp$request_mass_storage request or the REQUEST_MASS_STORAGE}
{ command may be used to direct allocation of all or part of the file to}
{ a specific class of mass storage.}
{   If the amc$current_volume mode is specified, additional space will be}
{ obtained from the last volume assigned to an existing file. If the}
{ amc$switch_volumes mode is specified for an existing file, space will be}
{ allocated from another volume selected by the system. The new volume will}
{ be of the same mass storage class as that of the predecessor.}
{   This request will be ignored if the local file is assigned to a terminal.}
{ If the local file is not assigned to mass storage or a terminal, this request}
{ is rejected.}
{
{        AMP$ALLOCATE (LOCAL_FILE_NAME, MODE, AMOUNT, STATUS)
{
{ LOCAL_FILE_NAME: (input) This parameter specifies the local name of the file}
{       for which mass storage space is to be allocated.}
{
{ MODE: (input) This parameter specifies whether the space will be}
{       allocated from the current volume or a new volume.}
{
{ AMOUNT: (input) This parameter specifies the number of bytes of mass}
{       storage space to be assigned to the file.}
{
{ STATUS: (output) This parameter specifies the request status.
{       CONDITION:  ame$ring_validation_error,
{                   ame$allocate_mode_param_error,
{                   ame$allocate_amount_error,
{                   ame$improper_device_class,
{                   ame$amount_exceeds_val_limit,
{                   ame$amount_exceeds_file_limit.
{       IDENTIFIER: amc$access_method_id.
