source: vbox/trunk/src/VBox/Devices/EFI/Firmware/ShellPkg/Library/UefiShellLevel1CommandsLib/Shift.c

/** @file
  Main file for Shift shell level 1 function.

  (C) Copyright 2015 Hewlett-Packard Development Company, L.P.<BR>
  Copyright (c) 2009 - 2018, Intel Corporation. All rights reserved.<BR>
  SPDX-License-Identifier: BSD-2-Clause-Patent

**/

#include "UefiShellLevel1CommandsLib.h"

/**
  Function for 'shift' command.

  @param[in] ImageHandle  Handle to the Image (NULL if Internal).
  @param[in] SystemTable  Pointer to the System Table (NULL if Internal).
**/
SHELL_STATUS
EFIAPI
ShellCommandRunShift (
  IN EFI_HANDLE        ImageHandle,
  IN EFI_SYSTEM_TABLE  *SystemTable
  )
{
  EFI_STATUS   Status;
  SCRIPT_FILE  *CurrentScriptFile;
  UINTN        LoopVar;

  Status = CommandInit ();
  ASSERT_EFI_ERROR (Status);

  if (!gEfiShellProtocol->BatchIsActive ()) {
    ShellPrintHiiEx (-1, -1, NULL, STRING_TOKEN (STR_NO_SCRIPT), gShellLevel1HiiHandle, L"shift");
    return (SHELL_UNSUPPORTED);
  }

  CurrentScriptFile = ShellCommandGetCurrentScriptFile ();
  ASSERT (CurrentScriptFile != NULL);

  if (CurrentScriptFile->Argc < 2) {
    ShellPrintHiiEx (-1, -1, NULL, STRING_TOKEN (STR_GEN_TOO_FEW), gShellLevel1HiiHandle, L"shift");
    return (SHELL_UNSUPPORTED);
  }

  for (LoopVar = 0; LoopVar < CurrentScriptFile->Argc; LoopVar++) {
    if (LoopVar == 0) {
      SHELL_FREE_NON_NULL (CurrentScriptFile->Argv[LoopVar]);
    }

    if (LoopVar < CurrentScriptFile->Argc -1) {
      CurrentScriptFile->Argv[LoopVar] = CurrentScriptFile->Argv[LoopVar+1];
    } else {
      CurrentScriptFile->Argv[LoopVar] = NULL;
    }
  }

  CurrentScriptFile->Argc--;
  return (SHELL_SUCCESS);
}