nix-super/doc/manual/src/quick-start.md
Jan Tojnar ca4d8ce9e2 doc: De-emphasize nix-env without -A
The manual uses `nix-env -i` without `-A` prominently, teaching a bad practice to newcomers.
2021-11-17 17:04:25 +01:00

2.4 KiB

Quick Start

This chapter is for impatient people who don't like reading documentation. For more in-depth information you are kindly referred to subsequent chapters.

  1. Install single-user Nix by running the following:

    $ bash <(curl -L https://nixos.org/nix/install)
    

    This will install Nix in /nix. The install script will create /nix using sudo, so make sure you have sufficient rights. (For other installation methods, see here.)

  2. See what installable packages are currently available in the channel:

    $ nix-env -qaP
    nixpkgs.docbook_xml_dtd_43                    docbook-xml-4.3
    nixpkgs.docbook_xml_dtd_45                    docbook-xml-4.5
    nixpkgs.firefox                               firefox-33.0.2
    nixpkgs.hello                                 hello-2.9
    nixpkgs.libxslt                               libxslt-1.1.28
    
  3. Install some packages from the channel:

    $ nix-env -iA nixpkgs.hello
    

    This should download pre-built packages; it should not build them locally (if it does, something went wrong).

  4. Test that they work:

    $ which hello
    /home/eelco/.nix-profile/bin/hello
    $ hello
    Hello, world!
    
  5. Uninstall a package:

    $ nix-env -e hello
    
  6. You can also test a package without installing it:

    $ nix-shell -p hello
    

    This builds or downloads GNU Hello and its dependencies, then drops you into a Bash shell where the hello command is present, all without affecting your normal environment:

    [nix-shell:~]$ hello
    Hello, world!
    
    [nix-shell:~]$ exit
    
    $ hello
    hello: command not found
    
  7. To keep up-to-date with the channel, do:

    $ nix-channel --update nixpkgs
    $ nix-env -u '*'
    

    The latter command will upgrade each installed package for which there is a “newer” version (as determined by comparing the version numbers).

  8. If you're unhappy with the result of a nix-env action (e.g., an upgraded package turned out not to work properly), you can go back:

    $ nix-env --rollback
    
  9. You should periodically run the Nix garbage collector to get rid of unused packages, since uninstalls or upgrades don't actually delete them:

    $ nix-collect-garbage -d