added the help command.

git-svn-id: https://hudson.dev.java.net/svn/hudson/trunk/hudson/main@17606 71c3de6d-444a-0410-be80-ed276b4c234a

core/src/main/java/hudson/cli/CLICommand.java

@@ -123,6 +123,12 @@ public abstract class CLICommand implements ExtensionPoint, Cloneable {
         return name.replaceAll("([a-z0-9])([A-Z])","$1-$2").toLowerCase(Locale.ENGLISH);
     }
 
+    /**
+     * Gets the quick summary of what this command does.
+     * Used by the help command to generate the list of commands.
+     */
+    public abstract String getShortDescription();
+
     public int main(List<String> args, InputStream stdin, PrintStream stdout, PrintStream stderr) {
         this.stdin = new BufferedInputStream(stdin);
         this.stdout = stdout;

core/src/main/java/hudson/cli/GroovyshCommand.java

@@ -20,6 +20,11 @@ import jline.Terminal;
  */
 @Extension
 public class GroovyshCommand extends CLICommand {
+    @Override
+    public String getShortDescription() {
+        return "Runs an interactive groovy shell";
+    }
+
     @Override
     public int main(List<String> args, InputStream stdin, PrintStream stdout, PrintStream stderr) {
         // this allows the caller to manipulate the JVM state, so require the admin privilege.

core/src/main/java/hudson/cli/HelpCommand.java

+package hudson.cli;
+
+import hudson.Extension;
+
+/**
+ * Show the list of all commands.
+ *
+ * @author Kohsuke Kawaguchi
+ */
+@Extension
+public class HelpCommand extends CLICommand {
+    @Override
+    public String getShortDescription() {
+        return "Lists all the available commands";
+    }
+
+    protected int run() {
+        for (CLICommand c : CLICommand.all()) {
+            stderr.println("  "+c.getName());
+            stderr.println("    "+c.getShortDescription());
+        }
+        return 0;
+    }
+}

core/src/main/java/hudson/cli/VersionCommand.java

@@ -33,6 +33,11 @@ import hudson.model.Hudson;
  */
 @Extension
 public class VersionCommand extends CLICommand {
+    @Override
+    public String getShortDescription() {
+        return "Shows the Hudson version";
+    }
+
     protected int run() {
         stdout.println(Hudson.VERSION);
         return 0;

core/src/main/java/hudson/model/Hudson.java

@@ -46,6 +46,7 @@ import hudson.DescriptorExtensionList;
 import hudson.ExtensionListView;
 import hudson.cli.CliEntryPoint;
 import hudson.cli.CLICommand;
+import hudson.cli.HelpCommand;
 import hudson.logging.LogRecorderManager;
 import hudson.lifecycle.Lifecycle;
 import hudson.model.Descriptor.FormException;
@@ -2671,6 +2672,7 @@ public final class Hudson extends Node implements ItemGroup<TopLevelItem>, Stapl
         }
 
         public int main(List<String> args, Locale locale, InputStream stdin, OutputStream stdout, OutputStream stderr) {
+            PrintStream out = new PrintStream(stdout);
             PrintStream err = new PrintStream(stderr);
 
             String subCmd = args.get(0);
@@ -2680,16 +2682,14 @@ public final class Hudson extends Node implements ItemGroup<TopLevelItem>, Stapl
                 SecurityContextHolder.getContext().setAuthentication(auth);
                 try {
                     // execute the command, do so with the originator of the request as the principal
-                    return cmd.main(args.subList(1,args.size()),
-                            stdin, new PrintStream(stdout), err);
+                    return cmd.main(args.subList(1,args.size()),stdin, out, err);
                 } finally {
                     SecurityContextHolder.getContext().setAuthentication(old);
                 }
             }
 
             err.println("No such command: "+subCmd);
-            for (CLICommand c : CLICommand.all())
-                err.println("  "+c.getName());
+            new HelpCommand().main(Collections.<String>emptyList(), stdin, out, err);
             return -1;
         }