- Add note on deploying a CLI project

- Fix error when a project without dependencies (and lock file) is deployed

README.md

@@ -1,6 +1,6 @@
 composer2nix
 ============
-`composer2nix` is a tool that can be used to generate [Nix](http://nixos.org)
+`composer2nix` is a tool that can be used to generate [Nix](http://nixos.org/nix)
 expressions for PHP [composer](https://getcomposer.org) packages.
 
 Nix integration makes it possible to use the Nix package manager (as opposed to
@@ -29,10 +29,10 @@ including its dependencies:
 
     $ nix-build
 
-An example use case scenario
+Deploying a web application project
-============================
+-----------------------------------
-We can use `composer2nix` to automate the deployment of a web application as
+We can use `composer2nix` to automate the deployment of a web application project
-part of a NixOS configuration.
+as part of a NixOS configuration.
 
 For example, we can create the following trivial PHP web application
 (`index.php`) that uses the [dompdf](http://dompdf.github.io/) library to
@@ -82,9 +82,11 @@ application and its dependencies.
 We can use Nix to build a bundle of our web application including its
 dependencies:
 
+```bash
 $ nix-build
 $ ls result/
 index.php  vendor/
+```
 
 (As may be observed, the `vendor/` folder contains all dependency artifacts).
 
@@ -115,17 +117,32 @@ in
 
 We can deploy the above NixOS configuration as follows:
 
-    $ nixos-rebuild switch
+```bash
+$ nixos-rebuild switch
+```
 
 If the above command succeeds, we have a running system with the Apache
 webserver serving our web application.
 
+Deploying a command-line utility project
+----------------------------------------
+In addition to web applications, we can also deploy command-line utility
+projects implemented in PHP.
+
+For example, for the `composer2nix` project, we can generate a CLI-specific
+expression by adding the `--executable` parameter:
+
+    $ composer2nix --executable
+
+We can install the `composer2nix` executable in our Nix profile by running:
+
+    $ nix-env -f default.nix -i
+
 Limitations
 ===========
 Currently, the state of this tool is that it is just a proof on concept
-implementation. As a result, it is lacking many features and probably buggy.
+implementation. For example, it does not support downloading from `fossil`
-Most importantly, only the `path`, `zip`, `git`, and `hg` dependencies are
+repositories.
-supported.
 
 License
 =======

src/Composer2Nix/composer-env.nix

@@ -57,19 +57,24 @@ rec {
         text = ''
           #! ${php}/bin/php
           <?php
-          $composerLockStr = file_get_contents($argv[1]);
+          if(file_exists($argv[1]))
-
-          if($composerLockStr === false)
           {
-              fwrite(STDERR, "Cannot open composer.lock contents\n");
+              $composerLockStr = file_get_contents($argv[1]);
-              exit(1);
+
+              if($composerLockStr === false)
+              {
+                  fwrite(STDERR, "Cannot open composer.lock contents\n");
+                  exit(1);
+              }
+              else
+              {
+                  $config = json_decode($composerLockStr);
+                  $packagesStr = json_encode($config->packages, JSON_PRETTY_PRINT | JSON_UNESCAPED_SLASHES);
+                  print($packagesStr);
+              }
           }
           else
-          {
+              print("[]");
-              $config = json_decode($composerLockStr);
-              $packagesStr = json_encode($config->packages, JSON_PRETTY_PRINT | JSON_UNESCAPED_SLASHES);
-              print($packagesStr);
-          }
           ?>
         '';
       };
@@ -170,7 +175,7 @@ rec {
 
         ${stdenv.lib.optionalString (removeComposerArtifacts) ''
           # Remove composer stuff
-          rm composer.json composer.lock
+          rm -f composer.json composer.lock
         ''}
     '';
   };