2 files changed, 112 insertions, 4 deletions
diff --git a/nixpkgs/pkgs/tools/nix/nixos-option/default.nix b/nixpkgs/pkgs/tools/nix/nixos-option/default.nix
index 56cb3e130038..7cca1eb7b38d 100644
--- a/nixpkgs/pkgs/tools/nix/nixos-option/default.nix
+++ b/nixpkgs/pkgs/tools/nix/nixos-option/default.nix
@@ -1,14 +1,33 @@
-{ lib, stdenv, boost, cmake, pkg-config, nix }:
+{ lib
+, stdenv
+, boost
+, cmake
+, pkg-config
+, installShellFiles
+, nix
+}:
 
 stdenv.mkDerivation {
   name = "nixos-option";
 
   src = ./.;
+  postInstall = ''
+    installManPage ${./nixos-option.8}
+  '';
 
   strictDeps = true;
-  nativeBuildInputs = [ cmake pkg-config ];
-  buildInputs = [ boost nix ];
-  cmakeFlags = [ "-DNIX_DEV_INCLUDEPATH=${nix.dev}/include/nix" ];
+  nativeBuildInputs = [
+    cmake
+    pkg-config
+    installShellFiles
+  ];
+  buildInputs = [
+    boost
+    nix
+  ];
+  cmakeFlags = [
+    "-DNIX_DEV_INCLUDEPATH=${nix.dev}/include/nix"
+  ];
 
   meta = with lib; {
     license = licenses.lgpl2Plus;
diff --git a/nixpkgs/pkgs/tools/nix/nixos-option/nixos-option.8 b/nixpkgs/pkgs/tools/nix/nixos-option/nixos-option.8
new file mode 100644
index 000000000000..28438b03580b
--- /dev/null
+++ b/nixpkgs/pkgs/tools/nix/nixos-option/nixos-option.8
@@ -0,0 +1,89 @@
+.Dd January 1, 1980
+.Dt nixos-option 8
+.Os
+.Sh NAME
+.Nm nixos-option
+.Nd inspect a NixOS configuration
+.
+.
+.
+.Sh SYNOPSIS
+.Nm
+.Op Fl r | -recursive
+.Op Fl I Ar path
+.Ar option.name
+.
+.
+.
+.Sh DESCRIPTION
+This command evaluates the configuration specified in
+.Pa /etc/nixos/configuration.nix
+and returns the properties of the option name given as argument.
+.
+.Pp
+When the option name is not an option, the command prints the list of attributes
+contained in the attribute set.
+.
+.
+.
+.Sh OPTIONS
+.Bl -tag -width indent
+.It Fl r , -recursive
+Print all the values at or below the specified path recursively.
+.
+.It Fl I Ar path
+This option is passed to the underlying
+.Xr nix-instantiate 1
+invocation.
+.El
+.
+.
+.
+.Sh ENVIRONMENT
+.Bl -tag -width indent
+.It Ev NIXOS_CONFIG
+Path to the main NixOS configuration module. Defaults to
+.Pa /etc/nixos/configuration.nix Ns
+\&.
+.El
+.
+.
+.
+.Sh EXAMPLES
+Investigate option values:
+.Bd -literal -offset indent
+$ nixos-option boot.loader
+This attribute set contains:
+generationsDir
+grub
+initScript
+
+$ nixos-option boot.loader.grub.enable
+Value:
+true
+
+Default:
+true
+
+Description:
+Whether to enable the GNU GRUB boot loader.
+
+Declared by:
+  "/nix/var/nix/profiles/per-user/root/channels/nixos/nixpkgs/nixos/modules/system/boot/loader/grub/grub.nix"
+
+Defined by:
+  "/nix/var/nix/profiles/per-user/root/channels/nixos/nixpkgs/nixos/modules/system/boot/loader/grub/grub.nix"
+.Ed
+.
+.
+.
+.Sh SEE ALSO
+.Xr configuration.nix 5
+.
+.
+.
+.Sh AUTHORS
+.An -nosplit
+.An Nicolas Pierron
+and
+.An the Nixpkgs/NixOS contributors