# vcpkg_backup_restore_env_vars The latest version of this document lives in the [vcpkg repo](https://github.com/Microsoft/vcpkg/blob/master/docs/maintainers/vcpkg_backup_restore_env_vars.md). Backup or restore the environment variables ## Usage: ```cmake vcpkg_backup_env_variables(VARS [<environment-variable>...]) vcpkg_restore_env_variables(VARS [<environment-variable>...]) ``` ### VARS The variables to back up or restore. These are placed in the parent scope, so you must backup and restore from the same scope. ## Notes One must always call `vcpkg_backup_env_variables` before `vcpkg_restore_env_variables`; however, `vcpkg_restore_env_variables` does not change the back up variables, and so you may call `restore` multiple times for one `backup`. ## Source [scripts/cmake/vcpkg\_backup\_restore\_env\_vars.cmake](https://github.com/Microsoft/vcpkg/blob/master/scripts/cmake/vcpkg_backup_restore_env_vars.cmake)