Introduction to nix-env: Managing Nix User Environments

# Name `nix-env` - manipulate or query Nix user environments # Synopsis `nix-env` *operation* [*options*] [*arguments…*] [`--option` *name* *value*] [`--arg` *name* *value*] [`--argstr` *name* *value*] [{`--file` | `-f`} *path*] [{`--profile` | `-p`} *path*] [`--system-filter` *system*] [`--dry-run`] # Description The command `nix-env` is used to manipulate Nix user environments. User environments are sets of software packages available to a user at some point in time. In other words, they are a synthesised view of the programs available in the Nix store. There may be many user environments: different users can have different environments, and individual users can switch between different environments. `nix-env` takes exactly one *operation* flag which indicates the subcommand to be performed. The following operations are available: - [`--install`](./nix-env/install.md) - [`--upgrade`](./nix-env/upgrade.md) - [`--uninstall`](./nix-env/uninstall.md) - [`--set`](./nix-env/set.md) - [`--set-flag`](./nix-env/set-flag.md) - [`--query`](./nix-env/query.md) - [`--switch-profile`](./nix-env/switch-profile.md) - [`--list-generations`](./nix-env/list-generations.md) - [`--delete-generations`](./nix-env/delete-generations.md) - [`--switch-generation`](./nix-env/switch-generation.md) - [`--rollback`](./nix-env/rollback.md) These pages can be viewed offline: - `man nix-env-<operation>`. Example: `man nix-env-install` - `nix-env --help --<operation>` Example: `nix-env --help --install` # Package sources `nix-env` can obtain packages from multiple sources: - An attribute set of derivations from: - The [default Nix expression](@docroot@/command-ref/files/default-nix-expression.md) (by default) - A Nix file, specified via `--file` - A [profile](@docroot@/command-ref/files/profiles.md), specified via `--from-profile` - A Nix expression that is a function which takes default expression as argument, specified via `--from-expression` - A [store path](@docroot@/store/store-path.md) # Selectors Several operations, such as [`nix-env --query`](./nix-env/query.md) and [`nix-env --install`](./nix-env/install.md), take a list of *arguments* that specify the packages on which to operate.

This document introduces the `nix-env` command, which is used to manipulate Nix user environments. It describes the available operations like install, upgrade, uninstall, query, etc., and how to access their documentation. It also explains the different sources from which `nix-env` can obtain packages, including Nix expressions, profiles, and store paths. Finally, it mentions the use of selectors to specify packages for certain operations.