From aa848bf39ad8f0956be0b7adb919ce4abc659ec5 Mon Sep 17 00:00:00 2001
From: Nicolas Mattia <nicolas@nmattia.com>
Date: Fri, 8 Feb 2019 19:29:48 +0100
Subject: [PATCH] Update README

---
 README.md        | 41 +++++++++++++++++++++++++++++++++++++----
 README.tpl.md    | 32 ++++++++++++++++++++++++++++----
 nix/packages.nix | 24 ++++++------------------
 3 files changed, 71 insertions(+), 26 deletions(-)

diff --git a/README.md b/README.md
index 2012a4e..333b8f9 100644
--- a/README.md
+++ b/README.md
@@ -2,7 +2,8 @@
 
 [![CircleCI](https://circleci.com/gh/nmattia/niv.svg?style=svg)](https://circleci.com/gh/nmattia/niv)
 
-A tool for dealing with third-party packages in [Nix].
+A tool for dealing with third-party packages in [Nix]. Read more about it in
+the [usage](#usage) section.
 
 ## Install
 
@@ -23,9 +24,20 @@ $ snack run -- <args>
 
 ## Usage
 
-* [Add](#add)
-* [Update](#update)
-* [Drop](#drop)
+`niv` simplifies [adding](#add) and [updating](#update) dependencies in Nix
+projects. It uses a single file, `nix/sources.json`, where it stores the data
+necessary for fetching and updating the packages.
+
+* [Add](#add): inserts a package in `nix/sources.json`.
+* [Update](#update): updates one or all packages in `nix/sources.json`.
+* [Drop](#drop): deletes a package from `nix/sources.json`.
+
+`niv` has two more utility functions:
+
+* [Init](#init): bootstraps a Nix projects, in particular creates a
+  `nix/sources.json` file containing `niv` and `nixpkgs` as well as a
+  `nix/sources.nix` file that returns the sources as a Nix object.
+* [Show](#show): shows the packages' information.
 
 ```
 NIV - Version manager for Nix projects
@@ -114,4 +126,25 @@ Available options:
 
 ```
 
+### Init
+
+```
+Usage: niv init 
+  Initialize a Nix project. Existing files won't be modified.
+
+Available options:
+  -h,--help                Show this help text
+
+```
+
+### show
+
+```
+Usage: niv show 
+
+Available options:
+  -h,--help                Show this help text
+
+```
+
 [Nix]: https://nixos.org/nix/
diff --git a/README.tpl.md b/README.tpl.md
index 184dc5c..da013ad 100644
--- a/README.tpl.md
+++ b/README.tpl.md
@@ -2,7 +2,8 @@
 
 [![CircleCI](https://circleci.com/gh/nmattia/niv.svg?style=svg)](https://circleci.com/gh/nmattia/niv)
 
-A tool for dealing with third-party packages in [Nix].
+A tool for dealing with third-party packages in [Nix]. Read more about it in
+the [usage](#usage) section.
 
 ## Install
 
@@ -23,9 +24,20 @@ $ snack run -- <args>
 
 ## Usage
 
-* [Add](#add)
-* [Update](#update)
-* [Drop](#drop)
+`niv` simplifies [adding](#add) and [updating](#update) dependencies in Nix
+projects. It uses a single file, `nix/sources.json`, where it stores the data
+necessary for fetching and updating the packages.
+
+* [Add](#add): inserts a package in `nix/sources.json`.
+* [Update](#update): updates one or all packages in `nix/sources.json`.
+* [Drop](#drop): deletes a package from `nix/sources.json`.
+
+`niv` has two more utility functions:
+
+* [Init](#init): bootstraps a Nix projects, in particular creates a
+  `nix/sources.json` file containing `niv` and `nixpkgs` as well as a
+  `nix/sources.nix` file that returns the sources as a Nix object.
+* [Show](#show): shows the packages' information.
 
 ```
 replace_niv_help
@@ -49,4 +61,16 @@ replace_niv_update_help
 replace_niv_drop_help
 ```
 
+### Init
+
+```
+replace_niv_init_help
+```
+
+### show
+
+```
+replace_niv_show_help
+```
+
 [Nix]: https://nixos.org/nix/
diff --git a/nix/packages.nix b/nix/packages.nix
index d228e5e..6906e42 100644
--- a/nix/packages.nix
+++ b/nix/packages.nix
@@ -12,27 +12,15 @@ rec
           (runCommand "niv_help" { buildInputs = [ niv ]; }
             "niv --help > $out"
           );
-        niv_add_help = builtins.readFile
-          (runCommand "niv_add_help" { buildInputs = [ niv ]; }
-            "niv add --help > $out"
-          );
-        niv_update_help = builtins.readFile
-          (runCommand "niv_update_help" { buildInputs = [ niv ]; }
-            "niv update --help > $out"
-          );
-        niv_drop_help = builtins.readFile
-          (runCommand "niv_drop_help" { buildInputs = [ niv ]; }
-            "niv drop --help > $out"
+        niv_cmd_help = cmd: builtins.readFile
+          (runCommand "niv_${cmd}_help" { buildInputs = [ niv ]; }
+            "niv ${cmd} --help > $out"
           );
+        cmds = [ "add" "update" "drop" "init" "show" ];
       };
     lib.replaceStrings
-      [
-        "replace_niv_help"
-        "replace_niv_add_help"
-        "replace_niv_update_help"
-        "replace_niv_drop_help"
-      ]
-      [ niv_help niv_add_help niv_update_help niv_drop_help ]
+      ([ "replace_niv_help" ] ++ (map (cmd: "replace_niv_${cmd}_help") cmds))
+      ([ niv_help ] ++ (map niv_cmd_help cmds))
       template
     );
   readme-test = runCommand "README-test" {}