table of contents
nix-env(1) | General Commands Manual | 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
- --upgrade
- --uninstall
- --set
- --set-flag
- --query
- --switch-profile
- --list-generations
- --delete-generations
- --switch-generation
- --rollback
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 (by default)
- A Nix file, specified via --file
- A profile, specified via --from-profile
- A Nix expression that is a function which takes default expression as argument, specified via --from-expression
- •
- A store path
Selectors¶
Several operations, such as nix-env --query and nix-env --install, 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:
- 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).
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}}