Provided by: nix-bin_2.26.3+dfsg-1ubuntu2_amd64 
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 path of 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.
{{#include ./opt-common.md}}
{{#include ../opt-common.md}}
{{#include ./env-common.md}}
{{#include ../env-common.md}}
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
nix-env --query(1)