From 89672dbe3c4ba97d53af7e839e8097e1ccbb4977 Mon Sep 17 00:00:00 2001
From: JBD <jbd@golang.org>
Date: Wed, 11 Jul 2018 12:14:45 -0700
Subject: [PATCH] fix out of bounds panic

---
 cmd.go  | 2 +-
 main.go | 4 ++++
 2 files changed, 5 insertions(+), 1 deletion(-)

diff --git a/cmd.go b/cmd.go
index 1bcd346..a59449e 100644
--- a/cmd.go
+++ b/cmd.go
@@ -185,7 +185,7 @@ func targetToAddr(target string) (*net.TCPAddr, error) {
 	}
 	port, err := internal.GetPort(pid)
 	if err != nil {
-		return nil, fmt.Errorf("couldn't get port for PID %s: %v", pid, err)
+		return nil, fmt.Errorf("couldn't get port for PID %v: %v", pid, err)
 	}
 	addr, _ := net.ResolveTCPAddr("tcp", "127.0.0.1:"+port)
 	return addr, nil
diff --git a/main.go b/main.go
index 1b78dac..867ae4b 100644
--- a/main.go
+++ b/main.go
@@ -72,6 +72,10 @@ func main() {
 	if !ok {
 		usage("unknown subcommand")
 	}
+	if len(os.Args) < 3 {
+		usage("Missing PID or address.")
+		os.Exit(1)
+	}
 	addr, err := targetToAddr(os.Args[2])
 	if err != nil {
 		fmt.Fprintf(os.Stderr, "Couldn't resolve addr or pid %v to TCPAddress: %v\n", os.Args[2], err)