nixos-rebuild

NixOS-rebuild is a command-line tool in NixOS, a Linux distribution built around the Nix package manager. It allows users to build and manage the system configuration of NixOS. The tool is used to deploy changes to the system configuration, applying updates and modifications. It operates by taking a "system declaration" file, written in the Nix Expression Language, which specifies all the packages, services, and system settings to be installed or changed. NixOS-rebuild then builds the system configuration according to the declaration and activates it. The tool enables users to switch between different system configurations, making it easy to roll back to previous configurations if necessary. It ensures consistent and reproducible deployments, with changes being applied atomically. Overall, NixOS-rebuild provides a powerful and flexible way to manage and update the system configuration of NixOS.