install go2rtc on bob

installs_on_host/go2rtc/pkg/shell/command.go

@@ -0,0 +1,59 @@
+package shell
+
+import (
+	"context"
+	"os/exec"
+)
+
+// Command like exec.Cmd, but with support:
+// - io.Closer interface
+// - Wait from multiple places
+// - Done channel
+type Command struct {
+	*exec.Cmd
+	ctx    context.Context
+	cancel context.CancelFunc
+	err    error
+}
+
+func NewCommand(s string) *Command {
+	ctx, cancel := context.WithCancel(context.Background())
+	args := QuoteSplit(s)
+	cmd := exec.CommandContext(ctx, args[0], args[1:]...)
+	cmd.SysProcAttr = procAttr
+	return &Command{cmd, ctx, cancel, nil}
+}
+
+func (c *Command) Start() error {
+	if err := c.Cmd.Start(); err != nil {
+		return err
+	}
+
+	go func() {
+		c.err = c.Cmd.Wait()
+		c.cancel() // release context resources
+	}()
+
+	return nil
+}
+
+func (c *Command) Wait() error {
+	<-c.ctx.Done()
+	return c.err
+}
+
+func (c *Command) Run() error {
+	if err := c.Start(); err != nil {
+		return err
+	}
+	return c.Wait()
+}
+
+func (c *Command) Done() <-chan struct{} {
+	return c.ctx.Done()
+}
+
+func (c *Command) Close() error {
+	c.cancel()
+	return nil
+}