write auto-detect logic for arch from uname

main-mshell.go

@@ -296,6 +296,10 @@ func parseInstallOpts() (*shexec.InstallOpts, error) {
 		if found {
 			continue
 		}
+		if argStr == "--detect" {
+			opts.Detect = true
+			continue
+		}
 		if base.IsOption(argStr) {
 			return nil, fmt.Errorf("invalid option '%s' passed to mshell --install", argStr)
 		}
@@ -402,6 +406,7 @@ func parseClientOpts() (*shexec.ClientOpts, error) {
 			opts.Command = strings.Join(iter.Rest(), " ")
 			break
 		}
+		return nil, fmt.Errorf("invalid option '%s' passed to mshell", argStr)
 	}
 	return opts, nil
 }
@@ -437,21 +442,29 @@ func handleInstall() (int, error) {
 	if opts.SSHOpts.SSHHost == "" {
 		return 1, fmt.Errorf("cannot install without '--ssh user@host' option")
 	}
-	fullArch := opts.ArchStr
+	if opts.Detect && opts.ArchStr != "" {
-	fields := strings.SplitN(fullArch, ".", 2)
+		return 1, fmt.Errorf("cannot supply both --detect and arch '%s'", opts.ArchStr)
-	if len(fields) != 2 {
-		return 1, fmt.Errorf("invalid arch format '%s' passed to mshell --install", fullArch)
 	}
-	goos, goarch := fields[0], fields[1]
+	if opts.ArchStr == "" && !opts.Detect {
-	if !base.ValidGoArch(goos, goarch) {
+		return 1, fmt.Errorf("must supply an arch string or '--detect' to auto detect")
-		return 1, fmt.Errorf("invalid arch '%s' passed to mshell --install", fullArch)
 	}
-	optName := base.GoArchOptFile(goos, goarch)
+	if opts.ArchStr != "" {
-	_, err = os.Stat(optName)
+		fullArch := opts.ArchStr
-	if err != nil {
+		fields := strings.SplitN(fullArch, ".", 2)
-		return 1, fmt.Errorf("cannot install mshell to remote host, cannot read '%s': %w", optName, err)
+		if len(fields) != 2 {
+			return 1, fmt.Errorf("invalid arch format '%s' passed to mshell --install", fullArch)
+		}
+		goos, goarch := fields[0], fields[1]
+		if !base.ValidGoArch(goos, goarch) {
+			return 1, fmt.Errorf("invalid arch '%s' passed to mshell --install", fullArch)
+		}
+		optName := base.GoArchOptFile(goos, goarch)
+		_, err = os.Stat(optName)
+		if err != nil {
+			return 1, fmt.Errorf("cannot install mshell to remote host, cannot read '%s': %w", optName, err)
+		}
+		opts.OptName = optName
 	}
-	opts.OptName = optName
 	err = shexec.RunInstallSSHCommand(opts)
 	if err != nil {
 		return 1, err

pkg/shexec/shexec.go

@@ -42,6 +42,7 @@ fi
 `
 
 const InstallCommand = `
+printf "\n##N{\"type\": \"init\", \"notfound\": true, \"uname\": \"%s | %s\"}\n" "$(uname -s)" "$(uname -m)";
 mkdir -p ~/.mshell/;
 cat > ~/.mshell/mshell.temp; 
 mv ~/.mshell/mshell.temp ~/.mshell/mshell;
@@ -246,6 +247,7 @@ type InstallOpts struct {
 	SSHOpts SharedSSHOpts
 	ArchStr string
 	OptName string
+	Detect  bool
 }
 
 type ClientOpts struct {
@@ -294,8 +296,8 @@ func (opts *InstallOpts) MakeExecCmd() *exec.Cmd {
 		moreSSHOpts = append(moreSSHOpts, userOpt)
 	}
 	// note that SSHOptsStr is *not* escaped
-	installCommand := strings.TrimSpace(InstallCommand)
+	command := strings.TrimSpace(InstallCommand)
-	sshCmd := fmt.Sprintf("ssh %s %s %s %s", strings.Join(moreSSHOpts, " "), opts.SSHOpts.SSHOptsStr, shellescape.Quote(opts.SSHOpts.SSHHost), shellescape.Quote(installCommand))
+	sshCmd := fmt.Sprintf("ssh %s %s %s %s", strings.Join(moreSSHOpts, " "), opts.SSHOpts.SSHOptsStr, shellescape.Quote(opts.SSHOpts.SSHHost), shellescape.Quote(command))
 	ecmd := exec.Command("bash", "-c", sshCmd)
 	return ecmd
 }
@@ -418,7 +420,20 @@ func ValidateRemoteFds(rfds []packet.RemoteFd) error {
 	return nil
 }
 
+func sendOptFile(input io.WriteCloser, optName string) error {
+	fd, err := os.Open(optName)
+	if err != nil {
+		return fmt.Errorf("cannot open '%s': %w", optName, err)
+	}
+	go func() {
+		defer input.Close()
+		io.Copy(input, fd)
+	}()
+	return nil
+}
+
 func RunInstallSSHCommand(opts *InstallOpts) error {
+	tryDetect := opts.Detect
 	ecmd := opts.MakeExecCmd()
 	inputWriter, err := ecmd.StdinPipe()
 	if err != nil {
@@ -435,21 +450,36 @@ func RunInstallSSHCommand(opts *InstallOpts) error {
 	go func() {
 		io.Copy(os.Stderr, stderrReader)
 	}()
-	fd, err := os.Open(opts.OptName)
+	if opts.OptName != "" {
-	if err != nil {
+		sendOptFile(inputWriter, opts.OptName)
-		return fmt.Errorf("cannot open '%s': %w", opts.OptName, err)
 	}
-	go func() {
-		defer inputWriter.Close()
-		io.Copy(inputWriter, fd)
-	}()
 	packetParser := packet.MakePacketParser(stdoutReader)
 	err = ecmd.Start()
 	if err != nil {
 		return fmt.Errorf("running ssh command: %w", err)
 	}
+	firstInit := true
 	for pk := range packetParser.MainCh {
-		if pk.GetType() == packet.InitPacketStr {
+		if pk.GetType() == packet.InitPacketStr && firstInit {
+			firstInit = false
+			initPacket := pk.(*packet.InitPacketType)
+			if !tryDetect {
+				continue // ignore
+			}
+			tryDetect = false
+			if initPacket.UName == "" {
+				return fmt.Errorf("cannot detect arch, no uname received from remote server")
+			}
+			goos, goarch, err := DetectGoArch(initPacket.UName)
+			if err != nil {
+				return fmt.Errorf("arch cannot be detected (might be incompatible with mshell): %w", err)
+			}
+			fmt.Printf("mshell detected remote architecture as '%s.%s'\n", goos, goarch)
+			optName := base.GoArchOptFile(goos, goarch)
+			sendOptFile(inputWriter, optName)
+			continue
+		}
+		if pk.GetType() == packet.InitPacketStr && !firstInit {
 			initPacket := pk.(*packet.InitPacketType)
 			if initPacket.Version == base.MShellVersion {
 				fmt.Printf("mshell %s, installed successfully at %s:~/.mshell/mshell\n", initPacket.Version, opts.SSHOpts.SSHHost)
@@ -537,16 +567,15 @@ func RunClientSSHCommandAndWait(opts *ClientOpts) (*packet.CmdDonePacketType, er
 		if pk.GetType() == packet.InitPacketStr {
 			initPk := pk.(*packet.InitPacketType)
 			if initPk.NotFound {
-				fmt.Printf("UNAME> %s\n", initPk.UName)
 				if initPk.UName == "" {
 					return nil, fmt.Errorf("mshell command not found on remote server, no uname detected")
 				}
-				goos, goarch, err := UNameStringToGoArch(initPk.UName)
+				goos, goarch, err := DetectGoArch(initPk.UName)
 				if err != nil {
 					return nil, fmt.Errorf("mshell command not found on remote server, architecture cannot be detected (might be incompatible with mshell): %w", err)
 				}
 				installCmd := opts.MakeInstallCommandString(goos, goarch)
-				return nil, fmt.Errorf("mshell command not found on remote server, can install with '%s'", installCmd)
+				return nil, fmt.Errorf("mshell command not found on remote server, can install with '%s' (or --auto-install)", installCmd)
 			}
 			if initPk.Version != base.MShellVersion {
 				return nil, fmt.Errorf("invalid remote mshell version 'v%s', must be v%s", initPk.Version, base.MShellVersion)
@@ -573,7 +602,7 @@ func RunClientSSHCommandAndWait(opts *ClientOpts) (*packet.CmdDonePacketType, er
 	return donePacket, nil
 }
 
-func UNameStringToGoArch(uname string) (string, string, error) {
+func DetectGoArch(uname string) (string, string, error) {
 	fields := strings.SplitN(uname, "|", 2)
 	if len(fields) != 2 {
 		return "", "", fmt.Errorf("invalid uname string returned")