From eaae4eb72a4ca9d99df573645ca7385705652630 Mon Sep 17 00:00:00 2001
From: hengyunabc <hengyunabc@gmail.com>
Date: Sun, 18 Nov 2018 23:42:35 +0800
Subject: [PATCH] add history command. close #298

---
 .../core/command/BuiltinCommandPack.java      |  2 +
 .../command/basic1000/HistoryCommand.java     | 77 +++++++++++++++++++
 2 files changed, 79 insertions(+)
 create mode 100644 core/src/main/java/com/taobao/arthas/core/command/basic1000/HistoryCommand.java

diff --git a/core/src/main/java/com/taobao/arthas/core/command/BuiltinCommandPack.java b/core/src/main/java/com/taobao/arthas/core/command/BuiltinCommandPack.java
index 6682f22b..cb209566 100644
--- a/core/src/main/java/com/taobao/arthas/core/command/BuiltinCommandPack.java
+++ b/core/src/main/java/com/taobao/arthas/core/command/BuiltinCommandPack.java
@@ -2,6 +2,7 @@ package com.taobao.arthas.core.command;
 
 import com.taobao.arthas.core.command.basic1000.ClsCommand;
 import com.taobao.arthas.core.command.basic1000.HelpCommand;
+import com.taobao.arthas.core.command.basic1000.HistoryCommand;
 import com.taobao.arthas.core.command.basic1000.KeymapCommand;
 import com.taobao.arthas.core.command.basic1000.ResetCommand;
 import com.taobao.arthas.core.command.basic1000.SessionCommand;
@@ -82,5 +83,6 @@ public class BuiltinCommandPack implements CommandResolver {
         commands.add(Command.create(SystemPropertyCommand.class));
         commands.add(Command.create(SystemEnvCommand.class));
         commands.add(Command.create(RedefineCommand.class));
+        commands.add(Command.create(HistoryCommand.class));
     }
 }
diff --git a/core/src/main/java/com/taobao/arthas/core/command/basic1000/HistoryCommand.java b/core/src/main/java/com/taobao/arthas/core/command/basic1000/HistoryCommand.java
new file mode 100644
index 00000000..2069738d
--- /dev/null
+++ b/core/src/main/java/com/taobao/arthas/core/command/basic1000/HistoryCommand.java
@@ -0,0 +1,77 @@
+package com.taobao.arthas.core.command.basic1000;
+
+import java.util.ArrayList;
+import java.util.List;
+
+import com.taobao.arthas.core.command.Constants;
+import com.taobao.arthas.core.shell.command.AnnotatedCommand;
+import com.taobao.arthas.core.shell.command.CommandProcess;
+import com.taobao.arthas.core.shell.session.Session;
+import com.taobao.arthas.core.shell.term.impl.TermImpl;
+import com.taobao.middleware.cli.annotations.Argument;
+import com.taobao.middleware.cli.annotations.Description;
+import com.taobao.middleware.cli.annotations.Name;
+import com.taobao.middleware.cli.annotations.Option;
+import com.taobao.middleware.cli.annotations.Summary;
+
+import io.termd.core.readline.Readline;
+
+/**
+ *
+ * @author hengyunabc 2018-11-18
+ *
+ */
+@Name("history")
+@Summary("Display command history")
+@Description(Constants.EXAMPLE + "  history\n" + "  history -c\n" + "  history 5\n")
+public class HistoryCommand extends AnnotatedCommand {
+    boolean clear = false;
+    int n = -1;
+
+    @Option(shortName = "c", longName = "clear")
+    @Description("clear history")
+    public void setClear(boolean clear) {
+        this.clear = clear;
+    }
+
+    @Argument(index = 0, argName = "n", required = false)
+    @Description("how many history commnads to display")
+    public void setNumber(int n) {
+        this.n = n;
+    }
+
+    @Override
+    public void process(CommandProcess process) {
+        Session session = process.session();
+        Object termObject = session.get(Session.TTY);
+        if (termObject != null && termObject instanceof TermImpl) {
+            TermImpl term = (TermImpl) termObject;
+            Readline readline = term.getReadline();
+            List<int[]> history = readline.getHistory();
+
+            if (clear) {
+                readline.setHistory(new ArrayList<int[]>());
+            } else {
+                StringBuilder sb = new StringBuilder();
+
+                int size = history.size();
+                if (n < 0) {
+                    n = size;
+                }
+
+                for (int i = 0; i < n; ++i) {
+                    int[] line = history.get(n - i - 1);
+                    sb.append(String.format("%5s  ", size - (n - i - 1)));
+                    for (int codePoint : line) {
+                        sb.append(Character.toChars(codePoint));
+                    }
+                    sb.append('\n');
+                }
+
+                process.write(sb.toString());
+            }
+        }
+
+        process.end();
+    }
+}