nixpkgs-suyu/nixos/doc/manual/configuration/ad-hoc-packages.xml
Eelco Dolstra 2cd7c1f198 Unify NixOS and Nixpkgs channel structure
This is primarily to ensure that

  -I nixpkgs=https://nixos.org/channels/nixos-unstable/nixexprs.tar.xz

and

  -I nixpkgs=https://github.com/NixOS/nixpkgs-channels/archive/nixos-unstable.tar.gz

and

  -I nixpkgs=https://nixos.org/channels/nixpkgs-unstable/nixexprs.tar.xz

behave consistently.

It also allows installing packages via "nix-env -iA nixos.<pkg>"
rather than "nixos.pkgs.<pkg>". It would be even better to allow
"nixpkgs.<pkg>", but that requires a change to nix-channel.

Fixes .
2015-08-05 17:37:11 +02:00

63 lines
2.2 KiB
XML

<section xmlns="http://docbook.org/ns/docbook"
xmlns:xlink="http://www.w3.org/1999/xlink"
xmlns:xi="http://www.w3.org/2001/XInclude"
version="5.0"
xml:id="sec-ad-hoc-packages">
<title>Ad-Hoc Package Management</title>
<para>With the command <command>nix-env</command>, you can install and
uninstall packages from the command line. For instance, to install
Mozilla Thunderbird:
<screen>
$ nix-env -iA nixos.thunderbird</screen>
If you invoke this as root, the package is installed in the Nix
profile <filename>/nix/var/nix/profiles/default</filename> and visible
to all users of the system; otherwise, the package ends up in
<filename>/nix/var/nix/profiles/per-user/<replaceable>username</replaceable>/profile</filename>
and is not visible to other users. The <option>-A</option> flag
specifies the package by its attribute name; without it, the package
is installed by matching against its package name
(e.g. <literal>thunderbird</literal>). The latter is slower because
it requires matching against all available Nix packages, and is
ambiguous if there are multiple matching packages.</para>
<para>Packages come from the NixOS channel. You typically upgrade a
package by updating to the latest version of the NixOS channel:
<screen>
$ nix-channel --update nixos
</screen>
and then running <literal>nix-env -i</literal> again. Other packages
in the profile are <emphasis>not</emphasis> affected; this is the
crucial difference with the declarative style of package management,
where running <command>nixos-rebuild switch</command> causes all
packages to be updated to their current versions in the NixOS channel.
You can however upgrade all packages for which there is a newer
version by doing:
<screen>
$ nix-env -u '*'
</screen>
</para>
<para>A package can be uninstalled using the <option>-e</option>
flag:
<screen>
$ nix-env -e thunderbird
</screen>
</para>
<para>Finally, you can roll back an undesirable
<command>nix-env</command> action:
<screen>
$ nix-env --rollback
</screen>
</para>
<para><command>nix-env</command> has many more flags. For details,
see the
<citerefentry><refentrytitle>nix-env</refentrytitle><manvolnum>1</manvolnum></citerefentry>
manpage or the Nix manual.</para>
</section>