nix-env(1)

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.

Packages are identified based on a name part and a version part of a symbolic derivation name (@docroot@/language/derivations.md#attr-name) :

•   name: Everything up to but not including the first dash (-) that is not followed by a letter.

•   version: The rest, excluding the separating dash.

    Example

    nix-env parses the symbolic derivation name apache-httpd-2.0.48 as:

        {
          "name": "apache-httpd",
          "version": "2.0.48"
        }

    Example

    nix-env parses the symbolic derivation name firefox.* as:

        {
          "name": "firefox.*",
          "version": ""
        }

The name parts of the arguments to nix-env are treated as extended regular expressions and matched against the name parts of derivation names in the package source. The match is case-sensitive. The regular expression can optionally be followed by a dash (-) and a version number; if omitted, any version of the package will match. For details on regular expressions, see regex(7) (https://linux.die.net/man/7/regex) .

    Example

    Common patterns for finding package names with nix-env:

    •   firefox

        Matches the package name firefox and any version.

    •   firefox-32.0

        Matches the package name firefox and version 32.0.

    •   gtk\\+

        Matches the package name gtk+. The + character must be escaped using a backslash (\) to prevent it from being interpreted as a quantifier, and the backslash must be escaped in turn with another backslash to ensure that the shell passes it on.

    •   .\*

        Matches any package name. This is the default for most commands.

    •   '.*zip.*'

        Matches any package name containing the string zip. Note the dots: '*zip*' does not work, because in a regular expression, the character * is interpreted as a quantifier.

    •   '.*(firefox|chromium).*'

        Matches any package name containing the strings firefox or chromium.

Files

nix-env operates on the following files.

{{#include ./files/default-nix-expression.md}}

{{#include ./files/profiles.md}}