; Execute a command. If the command fail, shows a message box and quit the installation

!macro ExecOrQuit Cmd MsgBoxText
  nsExec::Exec "${Cmd}"
  Pop $0

  ${If} $0 != 0
    MessageBox MB_ICONSTOP|MB_OK "${MsgBoxText}"
    Quit
  ${EndIf}
!macroend

!macro ExecWithRetry Cmd RetryMsg
  !define unqId ${__LINE__}

  StrCpy $0 1
  ${Do}
    nsExec::ExecToLog '${Cmd}'
    Pop $0
    ${If} $0 != 0
       MessageBox MB_RETRYCANCEL|MB_ICONEXCLAMATION "${RetryMsg}" IDRETRY labalRetry_${unqId} IDCANCEL labalCancel_${unqId}
       labalCancel_${unqId}:
          Quit
       labalRetry_${unqId}:
    ${EndIf}
  ${LoopUntil} $0 == 0

  !undef unqId
!macroend

.