From 81796c5baf6801718c2e55491baf725bd89c1753 Mon Sep 17 00:00:00 2001
From: Eelco Dolstra <eelco.dolstra@logicblox.com>
Date: Tue, 8 Jan 2013 02:13:33 +0100
Subject: [PATCH] =?UTF-8?q?Add=20a=20command=20=E2=80=98nixos-help?=
 =?UTF-8?q?=E2=80=99=20that=20opens=20the=20NixOS=20manual=20in=20a=20brow?=
 =?UTF-8?q?ser?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 modules/services/misc/nixos-manual.nix | 15 +++++++++++++--
 1 file changed, 13 insertions(+), 2 deletions(-)

diff --git a/modules/services/misc/nixos-manual.nix b/modules/services/misc/nixos-manual.nix
index 2e98d50b0ce..1a172904c45 100644
--- a/modules/services/misc/nixos-manual.nix
+++ b/modules/services/misc/nixos-manual.nix
@@ -16,6 +16,17 @@ let
     inherit pkgs options;
   };
 
+  entry = "${manual.manual}/share/doc/nixos/manual.html";
+
+  help = pkgs.writeScriptBin "nixos-help"
+    ''
+      #! ${pkgs.stdenv.shell} -e
+      if ! ''${BROWSER:-w3m} ${entry}; then
+        echo "$0: unable to start a web browser; please set \$BROWSER or install ‘w3m’"
+        exit 1
+      fi
+    '';
+
 in
 
 {
@@ -69,7 +80,7 @@ in
 
     system.build.manual = manual;
 
-    environment.systemPackages = [ manual.manpages ];
+    environment.systemPackages = [ manual.manpages help ];
 
     boot.extraTTYs = mkIf cfg.showManual ["tty${cfg.ttyNumber}"];
 
@@ -78,7 +89,7 @@ in
         { description = "NixOS Manual";
           wantedBy = [ "multi-user.target" ];
           serviceConfig =
-            { ExecStart = "${cfg.browser} ${manual.manual}/share/doc/nixos/manual.html";
+            { ExecStart = "${cfg.browser} ${entry}";
               StandardInput = "tty";
               StandardOutput = "tty";
               TTYPath = "/dev/tty${cfg.ttyNumber}";