Run a command when the virtual serial port is enabled

README.md

@@ -82,6 +82,14 @@ If the `-s` command line argument is specified, then kappanhang will create a
 **virtual serial port**, so other apps which don't support Hamlib can access
 the transceiver directly. Look at the app log to find out the name of the
 virtual serial port. It will be something like `/tmp/kappanhang-IC-705.pty`
+(the server's name appended to the string *kappanhang*). After the virtual
+serial port is created, the command specified with `-o` will be ran, which is
+`socat /tmp/kappanhang-IC-705.pty /tmp/vmware.pty` by default. Running the
+command can be disabled with `-o -`. The command is only executed once, as the
+virtual serial port will stay opened even if the RS-BA1 server disconnects.
+I use this command to link a COM port in a Windows OS running in VMware to
+the virtual serial port, so I can use the original RS-BA1 software remote
+control GUI.
 
 ### Icom IC-705 Wi-Fi notes
 

args.go

@@ -13,6 +13,7 @@ var connectAddress string
 var serialTCPPort uint16
 var enableSerialDevice bool
 var runCmd string
+var runCmdOnSerialPortCreated string
 var statusLogInterval time.Duration
 
 func parseArgs() {
@@ -22,6 +23,7 @@ func parseArgs() {
 	t := getopt.Uint16Long("serial-tcp-port", 'p', 4533, "Expose radio's serial port on this TCP port")
 	s := getopt.BoolLong("enable-serial-device", 's', "Expose radio's serial port as a virtual serial port")
 	r := getopt.StringLong("run", 'r', "rigctld -m 3085 -r :4533", "Exec cmd when connected, set to - to disable")
+	o := getopt.StringLong("run-serial", 'o', "socat /tmp/kappanhang-IC-705.pty /tmp/vmware.pty", "Exec cmd when virtual serial port is created, set to - to disable")
 	i := getopt.Uint16Long("log-interval", 'i', 100, "Status bar/log interval in milliseconds")
 
 	getopt.Parse()
@@ -37,5 +39,6 @@ func parseArgs() {
 	serialTCPPort = *t
 	enableSerialDevice = *s
 	runCmd = *r
+	runCmdOnSerialPortCreated = *o
 	statusLogInterval = time.Duration(*i) * time.Millisecond
 }

controlstream.go

@@ -260,6 +260,9 @@ func (s *controlStream) handleRead(r []byte) error {
 			statusLog.startPeriodicPrint()
 
 			startCmdIfNeeded()
+			if enableSerialDevice {
+				startSerialPortCmdIfNeeded()
+			}
 		}
 	}
 	return nil

runcmd.go

@@ -9,6 +9,7 @@ import (
 const startCmdDelay = time.Second
 
 var startedCmd *exec.Cmd
+var serialPortStartedCmd *exec.Cmd
 
 func doStartCmd() {
 	c := strings.Split(runCmd, " ")
@@ -17,7 +18,7 @@ func doStartCmd() {
 	if err == nil {
 		log.Print("cmd started: ", runCmd)
 	} else {
-		log.Error("error starting ", runCmd, " - ", err)
+		log.Error("error starting ", runCmd, ": ", err)
 		startedCmd = nil
 	}
 }
@@ -30,11 +31,35 @@ func startCmdIfNeeded() {
 	time.AfterFunc(startCmdDelay, doStartCmd)
 }
 
-func stopCmd() {
-	if startedCmd == nil {
-		return
-	}
-	if err := startedCmd.Process.Kill(); err != nil {
-		log.Error("failed to stop cmd ", runCmd)
+func doSerialPortStartCmd() {
+	c := strings.Split(runCmdOnSerialPortCreated, " ")
+	serialPortStartedCmd = exec.Command(c[0], c[1:]...)
+	err := serialPortStartedCmd.Start()
+	if err == nil {
+		log.Print("cmd started: ", runCmdOnSerialPortCreated)
+	} else {
+		log.Error("error starting ", runCmdOnSerialPortCreated, ": ", err)
+		serialPortStartedCmd = nil
+	}
+}
+
+func startSerialPortCmdIfNeeded() {
+	if serialPortStartedCmd != nil || runCmdOnSerialPortCreated == "-" {
+		return
+	}
+
+	time.AfterFunc(startCmdDelay, doSerialPortStartCmd)
+}
+
+func stopCmd() {
+	if startedCmd != nil {
+		if err := startedCmd.Process.Kill(); err != nil {
+			log.Error("failed to stop cmd ", runCmd, ": ", err)
+		}
+	}
+	if serialPortStartedCmd != nil {
+		if err := serialPortStartedCmd.Process.Kill(); err != nil {
+			log.Error("failed to stop cmd ", runCmdOnSerialPortCreated, ": ", err)
+		}
 	}
 }