Respond to basic process commands

main.go

@@ -4,9 +4,11 @@ import (
 	"bufio"
 	"fmt"
 	"os"
+	"strconv"
 	"strings"
 
 	"github.com/Dparker1990/dbg/command"
+	"github.com/Dparker1990/dbg/proctl"
 )
 
 type term struct {
@@ -14,16 +16,29 @@ type term struct {
 }
 
 func main() {
-	var (
-		t    = newTerm()
-		cmds = command.DebugCommands()
-	)
+	t := newTerm()
+
+	if len(os.Args) == 1 {
+		printStderrAndDie("You must provide a pid\n")
+	}
+
+	pid, err := strconv.Atoi(os.Args[1])
+	if err != nil {
+		printStderrAndDie(err)
+	}
+
+	dbgproc, err := proctl.NewDebugProcess(pid)
+	if err != nil {
+		printStderrAndDie("Could not start debugging process:", err)
+	}
+
+	cmds := command.DebugCommands()
+	registerProcessCommands(cmds, dbgproc)
 
 	for {
 		cmdstr, err := t.promptForInput()
 		if err != nil {
-			fmt.Fprint(os.Stderr, "Prompt for input failed.")
-			os.Exit(1)
+			printStderrAndDie("Prompt for input failed.\n")
 		}
 
 		cmd := cmds.Find(cmdstr)
@@ -34,6 +49,16 @@ func main() {
 	}
 }
 
+func printStderrAndDie(args ...interface{}) {
+	fmt.Fprint(os.Stderr, args)
+	os.Exit(1)
+}
+
+func registerProcessCommands(cmds *command.Commands, proc *proctl.DebuggedProcess) {
+	cmds.Register("step", proc.Step)
+	cmds.Register("continue", proc.Continue)
+}
+
 func newTerm() *term {
 	return &term{
 		stdin: bufio.NewReader(os.Stdin),