nix/doc/manual/source/command-ref/nix-env/query.md

Name

nix-env --query - display information about packages

Synopsis

nix-env {--query | -q} names… [--installed | --available | -a] [{--status | -s}] [{--attr-path | -P}] [--no-name] [{--compare-versions | -c}] [--system] [--drv-path] [--out-path] [--description] [--meta] [--xml] [--json] [{--prebuilt-only | -b}] [{--attr | -A} attribute-path]

Description

The query operation displays information about either the store paths that are installed in the current generation of the active profile (--installed), or the derivations that are available for installation in the active Nix expression (--available). It only prints information about derivations whose symbolic name matches one of names.

The derivations are sorted by their name attributes.

Source selection

The following flags specify the set of things on which the query operates.

• --installed

  The query operates on the store paths that are installed in the current generation of the active profile. This is the default.

• --available / -a

  The query operates on the derivations that are available in the active Nix expression.

Queries

The following flags specify what information to display about the selected derivations. Multiple flags may be specified, in which case the information is shown in the order given here. Note that the name of the derivation is shown unless --no-name is specified.

• --xml

  Print the result in an XML representation suitable for automatic processing by other tools. The root element is called items, which contains a item element for each available or installed derivation. The fields discussed below are all stored in attributes of the item elements.

• --json

  Print the result in a JSON representation suitable for automatic processing by other tools.

• --prebuilt-only / -b

  Show only derivations for which a substitute is registered, i.e., there is a pre-built binary available that can be downloaded in lieu of building the derivation. Thus, this shows all packages that probably can be installed quickly.

• --status / -s

  Print the status of the derivation. The status consists of three characters. The first is I or -, indicating whether the derivation is currently installed in the current generation of the active profile. This is by definition the case for --installed, but not for --available. The second is P or -, indicating whether the derivation is present on the system. This indicates whether installation of an available derivation will require the derivation to be built. The third is S or -, indicating whether a substitute is available for the derivation.

• --attr-path / -P

  Print the attribute path of the derivation, which can be used to unambiguously select it using the --attr option available in commands that install derivations like nix-env --install. This option only works together with --available

• --no-name

  Suppress printing of the name attribute of each derivation.

• --compare-versions / -c

  Compare installed versions to available versions, or vice versa (if --available is given). This is useful for quickly seeing whether upgrades for installed packages are available in a Nix expression. A column is added with the following meaning:

  • < version

    A newer version of the package is available or installed.

  • = version

    At most the same version of the package is available or installed.

  • > version

    Only older versions of the package are available or installed.

  • - ?

    No version of the package is available or installed.

• --system

  Print the system attribute of the derivation.

• --drv-path

  Print the store path to the store derivation.

• --out-path

  Print the output path of the derivation.

• --description

  Print a short (one-line) description of the derivation, if available. The description is taken from the meta.description attribute of the derivation.

• --meta

  Print all of the meta-attributes of the derivation. This option is only available with --xml or --json.

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Examples

To show installed packages:

$ nix-env --query
bison-1.875c
docbook-xml-4.2
firefox-1.0.4
MPlayer-1.0pre7
ORBit2-2.8.3
…

To show available packages:

$ nix-env --query --available
firefox-1.0.7
GConf-2.4.0.1
MPlayer-1.0pre7
ORBit2-2.8.3
…

To show the status of available packages:

$ nix-env --query --available --status
-P- firefox-1.0.7   (not installed but present)
--S GConf-2.4.0.1   (not present, but there is a substitute for fast installation)
--S MPlayer-1.0pre3 (i.e., this is not the installed MPlayer, even though the version is the same!)
IP- ORBit2-2.8.3    (installed and by definition present)
…

To show available packages in the Nix expression foo.nix:

$ nix-env --file ./foo.nix --query --available
foo-1.2.3

To compare installed versions to what’s available:

$ nix-env --query --compare-versions
...
acrobat-reader-7.0 - ?      (package is not available at all)
autoconf-2.59      = 2.59   (same version)
firefox-1.0.4      < 1.0.7  (a more recent version is available)
...

To show all packages with “zip” in the name:

$ nix-env --query --available '.*zip.*'
bzip2-1.0.6
gzip-1.6
zip-3.0
…

To show all packages with “firefox” or “chromium” in the name:

$ nix-env --query --available '.*(firefox|chromium).*'
chromium-37.0.2062.94
chromium-beta-38.0.2125.24
firefox-32.0.3
firefox-with-plugins-13.0.1
…

To show all packages in the latest revision of the Nixpkgs repository:

$ nix-env --file https://github.com/NixOS/nixpkgs/archive/master.tar.gz --query --available