Function DoHelpUpdate

ShellPkg/Application/Shell/Shell.c:2237–2283

Reprocess the command line to direct all -? to the help command. if found, will add "help" as argv[0], and move the rest later. @param[in,out] CmdLine pointer to the command line to update **/

  @param[in,out] CmdLine        pointer to the command line to update
**/
EFI_STATUS
DoHelpUpdate(
  IN OUT CHAR16 **CmdLine
  )
{
  CHAR16 *CurrentParameter;
  CHAR16 *Walker;
  CHAR16 *NewCommandLine;
  EFI_STATUS Status;
  UINTN  NewCmdLineSize;

  Status = EFI_SUCCESS;

  CurrentParameter = AllocateZeroPool(StrSize(*CmdLine));
  if (CurrentParameter == NULL) {
    return (EFI_OUT_OF_RESOURCES);
  }

  Walker = *CmdLine;
  while(Walker != NULL && *Walker != CHAR_NULL) {
    if (!EFI_ERROR(GetNextParameter(&Walker, &CurrentParameter, StrSize(*CmdLine), TRUE))) {
    if (StrStr(CurrentParameter, L"-?") == CurrentParameter) {
        CurrentParameter[0] = L' ';
        CurrentParameter[1] = L' ';
        NewCmdLineSize = StrSize(L"help ") + StrSize(*CmdLine);
        NewCommandLine = AllocateZeroPool(NewCmdLineSize);
      if (NewCommandLine == NULL) {
        Status = EFI_OUT_OF_RESOURCES;
        break;
      }

      //
      // We know the space is sufficient since we just calculated it.
      //
        StrnCpyS(NewCommandLine, NewCmdLineSize/sizeof(CHAR16), L"help ", 5);
        StrnCatS(NewCommandLine, NewCmdLineSize/sizeof(CHAR16), *CmdLine, StrLen(*CmdLine));
      SHELL_FREE_NON_NULL(*CmdLine);
      *CmdLine = NewCommandLine;
      break;
    }
  }
  }

  SHELL_FREE_NON_NULL(CurrentParameter);

  return (Status);
}

/**
  Function to update the shell variable "lasterror".