Rework into arbitrary command exectutor

README.md

@@ -1,9 +1,17 @@
+# Description
+This is a small extension to [DuetSoftwareFramework](https://github.com/christhamm/DuetSoftwareFramework)
+to execute arbitrary system commands when a user-defined `M-Code` is encountered.
+
+An example usage would be to execute system shutdown on the SBC when a e.g. `M7722` is run.
+
 # Usage
 ```
-$ ./shutdownsbc --help
-Usage of ./shutdownsbc:
-  -shutdownMCode int
-	  Code that will initiate shutdown of the SBC (default 7722)
+$ ./execonmcode --help
+Usage of ./execonmcode:
+  -command string
+        Command to execute
+  -mCode int
+        Code that will initiate execution of the command (default 7722)
   -socketPath string
-	  Path to socket (default "/var/run/duet.sock")
+        Path to socket (default "/var/run/duet.sock")
 ```

cmd/eom/execonmcode.go

@@ -0,0 +1,35 @@
+package main
+
+import (
+	"flag"
+	"log"
+
+	"github.com/wilriker/execonmcode"
+	"github.com/wilriker/goduetapiclient/connection"
+)
+
+type settings struct {
+	socketPath string
+	mCode      int64
+	command    string
+}
+
+func main() {
+	s := settings{}
+
+	flag.StringVar(&s.socketPath, "socketPath", connection.DefaultSocketPath, "Path to socket")
+	flag.Int64Var(&s.mCode, "mCode", 7722, "Code that will initiate execution of the command")
+	flag.StringVar(&s.command, "command", "", "Command to execute")
+	flag.Parse()
+
+	if s.mCode < 0 {
+		log.Fatal("--mCode must be >= 0")
+	}
+
+	if s.command == "" {
+		log.Fatal("--command must not be empty")
+	}
+
+	e := execonmcode.NewExecutor(s.socketPath, s.command, s.mCode)
+	e.Run()
+}

executor.go

@@ -0,0 +1,65 @@
+package execonmcode
+
+import (
+	"log"
+	"os/exec"
+	"strings"
+
+	"github.com/wilriker/goduetapiclient/connection"
+	"github.com/wilriker/goduetapiclient/connection/initmessages"
+	"github.com/wilriker/goduetapiclient/types"
+)
+
+type Executor struct {
+	socketPath string
+	mCode      int64
+	command    string
+	args       []string
+}
+
+func NewExecutor(socketPath, command string, mCode int64) *Executor {
+	s := strings.Split(command, " ")
+	a := []string{}
+	if len(s) > 1 {
+		a = s[1:]
+	}
+	c := s[0]
+	return &Executor{
+		socketPath: socketPath,
+		command:    c,
+		args:       a,
+		mCode:      mCode,
+	}
+}
+
+func (e *Executor) Run() {
+
+	ic := connection.InterceptConnection{}
+	err := ic.Connect(initmessages.InterceptionModePre, e.socketPath)
+	if err != nil {
+		log.Fatal(err)
+	}
+	defer ic.Close()
+
+	for {
+		c, err := ic.ReceiveCode()
+		if err != nil {
+			log.Println("Error:", err)
+			continue
+		}
+		if c.Type == types.MCode && c.MajorNumber != nil && *c.MajorNumber == e.mCode {
+			cmd := exec.Command(e.command, e.args...)
+			err := cmd.Run()
+			if err != nil {
+				err = ic.ResolveCode(types.Error, err.Error())
+			} else {
+				err = ic.ResolveCode(types.Success, "")
+			}
+			if err != nil {
+				log.Println("Error:", err)
+			}
+		} else {
+			ic.IgnoreCode()
+		}
+	}
+}

go.mod

@@ -1,4 +1,4 @@
-module github.com/wilriker/dsfext-shutdownsbc
+module github.com/wilriker/execonmcode
 
 go 1.13
 

shutdownsbc.service

@@ -4,7 +4,7 @@ After=duetcontrolserver.service
 Requires=duetcontrolserver.service
 
 [Service]
-ExecStart=/usr/local/bin/shutdownsbc
+ExecStart=/usr/local/bin/execonmcode --command "poweroff"
 Restart=always
 RestartSec=10