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## Profiles

A directory that contains links to profiles managed by `nix-env` and `nix profile`:

- `$XDG_STATE_HOME/nix/profiles` for regular users
- `$NIX_STATE_DIR/profiles/per-user/root` if the user is `root`

A profile is a directory of symlinks to files in the Nix store.

### Filesystem layout

Profiles are versioned as follows. When using a profile named path, path is a symlink to path`-`N`-link`, where N is the version of the profile. In turn, path`-`N`-link` is a symlink to a path in the Nix store. For example:

    $ ls -l ~alice/.local/state/nix/profiles/profile*
    lrwxrwxrwx 1 alice users 14 Nov 25 14:35 /home/alice/.local/state/nix/profiles/profile -> profile-7-link
    lrwxrwxrwx 1 alice users 51 Oct 28 16:18 /home/alice/.local/state/nix/profiles/profile-5-link -> /nix/store/q69xad13ghpf7ir87h0b2gd28lafjj1j-profile
    lrwxrwxrwx 1 alice users 51 Oct 29 13:20 /home/alice/.local/state/nix/profiles/profile-6-link -> /nix/store/6bvhpysd7vwz7k3b0pndn7ifi5xr32dg-profile
    lrwxrwxrwx 1 alice users 51 Nov 25 14:35 /home/alice/.local/state/nix/profiles/profile-7-link -> /nix/store/mp0x6xnsg0b8qhswy6riqvimai4gm677-profile

Each of these symlinks is a root for the Nix garbage collector.

The contents of the store path corresponding to each version of the profile is a tree of symlinks to the files of the installed packages, e.g.

    $ ll -R ~eelco/.local/state/nix/profiles/profile-7-link/
    /home/eelco/.local/state/nix/profiles/profile-7-link/:
    total 20
    dr-xr-xr-x 2 root root 4096 Jan  1  1970 bin
    -r--r--r-- 2 root root 1402 Jan  1  1970 manifest.nix
    dr-xr-xr-x 4 root root 4096 Jan  1  1970 share

    /home/eelco/.local/state/nix/profiles/profile-7-link/bin:
    total 20
    lrwxrwxrwx 5 root root 79 Jan  1  1970 chromium -> /nix/store/ijm5k0zqisvkdwjkc77mb9qzb35xfi4m-chromium-86.0.4240.111/bin/chromium
    lrwxrwxrwx 7 root root 87 Jan  1  1970 spotify -> /nix/store/w9182874m1bl56smps3m5zjj36jhp3rn-spotify-1.1.26.501.gbe11e53b-15/bin/spotify
    lrwxrwxrwx 3 root root 79 Jan  1  1970 zoom-us -> /nix/store/wbhg2ga8f3h87s9h5k0slxk0m81m4cxl-zoom-us-5.3.469451.0927/bin/zoom-us

    /home/eelco/.local/state/nix/profiles/profile-7-link/share/applications:
    total 12
    lrwxrwxrwx 4 root root 120 Jan  1  1970 chromium-browser.desktop -> /nix/store/4cf803y4vzfm3gyk3vzhzb2327v0kl8a-chromium-unwrapped-86.0.4240.111/share/applications/chromium-browser.desktop
    lrwxrwxrwx 7 root root 110 Jan  1  1970 spotify.desktop -> /nix/store/w9182874m1bl56smps3m5zjj36jhp3rn-spotify-1.1.26.501.gbe11e53b-15/share/applications/spotify.desktop
    lrwxrwxrwx 3 root root 107 Jan  1  1970 us.zoom.Zoom.desktop -> /nix/store/wbhg2ga8f3h87s9h5k0slxk0m81m4cxl-zoom-us-5.3.469451.0927/share/applications/us.zoom.Zoom.desktop

    …

Each profile version contains a manifest file:

- `manifest.nix` used by `nix-env`.
- `manifest.json` used by `nix profile` (experimental).

## User profile link

A symbolic link to the user's current profile:

- `~/.nix-profile`
- `$XDG_STATE_HOME/nix/profile` if `use-xdg-base-directories` is set to `true`.

By default, this symlink points to:

- `$XDG_STATE_HOME/nix/profiles/profile` for regular users
- `$NIX_STATE_DIR/profiles/per-user/root/profile` for `root`

The `PATH` environment variable should include `/bin` subdirectory of the profile link (e.g. `~/.nix-profile/bin`) for the user environment to be visible to the user. The installer sets this up by default, unless you enable `use-xdg-base-directories`.