arthas-boot support attach-only and help. #278

boot/src/main/java/com/taobao/arthas/boot/Bootstrap.java

@@ -43,6 +43,8 @@ public class Bootstrap {
     private static final int DEFAULT_HTTP_PORT = 8563;
     private static final String DEFAULT_TARGET_IP = "127.0.0.1";
 
+    private boolean help = false;
+
     private int pid = -1;
     private String targetIp = DEFAULT_TARGET_IP;
     private int telnetPort = DEFAULT_TELNET_PORT;
@@ -83,6 +85,12 @@ public class Bootstrap {
         this.pid = pid;
     }
 
+    @Option(shortName = "h", longName = "help", flag = true)
+    @Description("Print usage")
+    public void setHelp(boolean help) {
+        this.help = help;
+    }
+
     @Option(longName = "target-ip")
     @Description("The target jvm listen ip, default 127.0.0.1")
     public void setTargetIp(String targetIp) {
@@ -125,7 +133,7 @@ public class Bootstrap {
         this.useHttps = useHttps;
     }
 
-    @Option(longName = "attach-only")
+    @Option(longName = "attach-only", flag = true)
     @Description("attach target process only, do not connect")
     public void setAttachOnly(boolean attachOnly) {
         this.attachOnly = attachOnly;
@@ -167,6 +175,11 @@ public class Bootstrap {
             System.exit(1);
         }
 
+        if (bootStrap.isHelp()) {
+            System.out.println(usage(cli));
+            System.exit(0);
+        }
+
         // check telnet/http port
         int telnetPortPid = -1;
         int httpPortPid = -1;
@@ -280,6 +293,10 @@ public class Bootstrap {
 
         logger.info("Attach process {} success.", pid);
 
+        if (bootStrap.isAttachOnly()) {
+            System.exit(0);
+        }
+
         // start java telnet client
         // find arthas-client.jar
         URLClassLoader classLoader = new URLClassLoader(
@@ -385,4 +402,8 @@ public class Bootstrap {
     public int getPid() {
         return pid;
     }
+
+    public boolean isHelp() {
+        return help;
+    }
 }