expose tssh as a library

README.md

@@ -170,6 +170,44 @@ trzsz-ssh ( tssh ) offers additional useful features:
 
 - Download from the [GitHub Releases](https://github.com/trzsz/trzsz-ssh/releases), unzip and add to `PATH` environment.
 
+## Development
+
+The `github.com/trzsz/trzsz-ssh/tssh` can be used as a library, for example:
+
+```go
+package main
+
+import (
+	"log"
+	"os"
+
+	"github.com/trzsz/trzsz-ssh/tssh"
+)
+
+func main() {
+	// Example 1: execute command on remote server
+	client, err := tssh.SshLogin(&tssh.SshArgs{Destination: "[email protected]"})
+	if err != nil {
+		log.Fatal(err)
+	}
+	defer client.Close()
+	session, err := client.NewSession()
+	if err != nil {
+		log.Fatal(err)
+	}
+	defer session.Close()
+	output, err := session.CombinedOutput("whoami")
+	if err != nil {
+		log.Fatal(err)
+	}
+	log.Printf("I'm %s", string(output))
+
+	// Example 2: run the tssh program
+	code := tssh.TsshMain([]string{"-t", "[email protected]", "bash -l"})
+	os.Exit(code)
+}
+```
+
 ## Contributing
 
 Welcome and thank you for considering contributing. We appreciate all forms of support, from coding and testing to documentation and CI/CD improvements.

cmd/tssh/main.go

@@ -31,5 +31,5 @@ import (
 )
 
 func main() {
-	os.Exit(tssh.TsshMain())
+	os.Exit(tssh.TsshMain(os.Args[1:]))
 }

tssh/agent.go

@@ -88,7 +88,7 @@ func getAgentClient(args *sshArgs, param *sshParam) agent.ExtendedAgent {
 	return agentClient
 }
 
-func forwardToRemote(client sshClient, addr string) error {
+func forwardToRemote(client SshClient, addr string) error {
 	channels := client.HandleChannelOpen(kAgentChannelType)
 	if channels == nil {
 		return fmt.Errorf("agent: already have handler for %s", kAgentChannelType)
@@ -122,7 +122,7 @@ func forwardAgentRequest(channel ssh.Channel, addr string) {
 	forwardChannel(channel, conn)
 }
 
-func requestAgentForwarding(session sshSession) error {
+func requestAgentForwarding(session SshSession) error {
 	ok, err := session.SendRequest(kAgentRequestName, true, nil)
 	if err != nil {
 		return err

tssh/config.go

@@ -94,7 +94,7 @@ type tsshConfig struct {
 	wildcardPatterns    []*ssh_config.Pattern
 }
 
-var userConfig = &tsshConfig{}
+var userConfig *tsshConfig
 
 func parseTsshConfig() {
 	path := filepath.Join(userHomeDir, ".tssh.conf")
@@ -218,8 +218,8 @@ func showTsshConfig() {
 	}
 }
 
-func initUserConfig(configFile string) error {
-	var err error
+func initUserConfig(configFile string) (err error) {
+	userConfig = &tsshConfig{}
 	userHomeDir, err = os.UserHomeDir()
 	if err != nil {
 		debug("user home dir failed: %v", err)

tssh/ctrl_unix.go

@@ -318,7 +318,7 @@ func startControlMaster(args *sshArgs, sshPath string) error {
 	return nil
 }
 
-func connectViaControl(args *sshArgs, param *sshParam) sshClient {
+func connectViaControl(args *sshArgs, param *sshParam) SshClient {
 	ctrlMaster := getOptionConfig(args, "ControlMaster")
 	ctrlPath := getOptionConfig(args, "ControlPath")
 

tssh/ctrl_windows.go

@@ -28,7 +28,7 @@ import (
 	"strings"
 )
 
-func connectViaControl(args *sshArgs, param *sshParam) sshClient {
+func connectViaControl(args *sshArgs, param *sshParam) SshClient {
 	ctrlMaster := getOptionConfig(args, "ControlMaster")
 	ctrlPath := getOptionConfig(args, "ControlPath")
 

tssh/env.go

@@ -118,7 +118,7 @@ func getSetEnvs(args *sshArgs) ([]*sshEnv, error) {
 	return envs, nil
 }
 
-func sendAndSetEnv(args *sshArgs, session sshSession) (string, error) {
+func sendAndSetEnv(args *sshArgs, session SshSession) (string, error) {
 	sendEnvs, err := getSendEnvs(args)
 	if err != nil {
 		return "", err

tssh/forward.go

@@ -227,7 +227,7 @@ func listenOnLocal(args *sshArgs, addr *string, port string) (listeners []net.Li
 	return
 }
 
-func listenOnRemote(args *sshArgs, client sshClient, addr *string, port string) (listeners []net.Listener) {
+func listenOnRemote(args *sshArgs, client SshClient, addr *string, port string) (listeners []net.Listener) {
 	listen := func(network, address string) {
 		listener, err := client.Listen(network, address)
 		if err != nil {
@@ -251,7 +251,7 @@ func listenOnRemote(args *sshArgs, client sshClient, addr *string, port string)
 	return
 }
 
-func stdioForward(client sshClient, addr string) (*sync.WaitGroup, error) {
+func stdioForward(client SshClient, addr string) (*sync.WaitGroup, error) {
 	conn, err := client.DialTimeout("tcp", addr, 10*time.Second)
 	if err != nil {
 		return nil, fmt.Errorf("stdio forward failed: %v", err)
@@ -283,7 +283,7 @@ func (d sshResolver) Resolve(ctx context.Context, name string) (context.Context,
 	return ctx, []byte{}, nil
 }
 
-func dynamicForward(client sshClient, b *bindCfg, args *sshArgs) {
+func dynamicForward(client SshClient, b *bindCfg, args *sshArgs) {
 	server, err := socks5.New(&socks5.Config{
 		Resolver: &sshResolver{},
 		Dial: func(ctx context.Context, network, addr string) (net.Conn, error) {
@@ -334,7 +334,7 @@ func netForward(local, remote net.Conn) {
 	<-done
 }
 
-func localForward(client sshClient, f *forwardCfg, args *sshArgs) {
+func localForward(client SshClient, f *forwardCfg, args *sshArgs) {
 	remoteAddr := joinHostPort(f.destHost, strconv.Itoa(f.destPort))
 	for _, listener := range listenOnLocal(args, f.bindAddr, strconv.Itoa(f.bindPort)) {
 		go func(listener net.Listener) {
@@ -360,7 +360,7 @@ func localForward(client sshClient, f *forwardCfg, args *sshArgs) {
 	}
 }
 
-func remoteForward(client sshClient, f *forwardCfg, args *sshArgs) {
+func remoteForward(client SshClient, f *forwardCfg, args *sshArgs) {
 	localAddr := joinHostPort(f.destHost, strconv.Itoa(f.destPort))
 	for _, listener := range listenOnRemote(args, client, f.bindAddr, strconv.Itoa(f.bindPort)) {
 		go func(listener net.Listener) {
@@ -386,7 +386,7 @@ func remoteForward(client sshClient, f *forwardCfg, args *sshArgs) {
 	}
 }
 
-func sshForward(client sshClient, args *sshArgs, param *sshParam) error {
+func sshForward(client SshClient, args *sshArgs, param *sshParam) error {
 	// clear all forwardings
 	if strings.ToLower(getOptionConfig(args, "ClearAllForwardings")) == "yes" {
 		return nil
@@ -451,7 +451,7 @@ type x11Request struct {
 	ScreenNumber     uint32
 }
 
-func sshX11Forward(args *sshArgs, client sshClient, session sshSession) {
+func sshX11Forward(args *sshArgs, client SshClient, session SshSession) {
 	if args.NoX11Forward || !args.X11Untrusted && !args.X11Trusted && strings.ToLower(getOptionConfig(args, "ForwardX11")) != "yes" {
 		return
 	}

tssh/login.go

@@ -992,7 +992,7 @@ func getNetworkAddressFamily(args *sshArgs) string {
 	}
 }
 
-func sshConnect(args *sshArgs, client sshClient, proxy string) (sshClient, *sshParam, bool, error) {
+func sshConnect(args *sshArgs, client SshClient, proxy string) (SshClient, *sshParam, bool, error) {
 	param, err := getSshParam(args)
 	if err != nil {
 		return nil, nil, false, err
@@ -1028,7 +1028,7 @@ func sshConnect(args *sshArgs, client sshClient, proxy string) (sshClient, *sshP
 
 	network := getNetworkAddressFamily(args)
 
-	proxyConnect := func(client sshClient, proxy string) (sshClient, *sshParam, bool, error) {
+	proxyConnect := func(client SshClient, proxy string) (SshClient, *sshParam, bool, error) {
 		debug("login to [%s], addr: %s", args.Destination, param.addr)
 		conn, err := client.DialTimeout(network, param.addr, 10*time.Second)
 		if err != nil {
@@ -1078,7 +1078,7 @@ func sshConnect(args *sshArgs, client sshClient, proxy string) (sshClient, *sshP
 	}
 
 	// has proxies
-	var proxyClient sshClient
+	var proxyClient SshClient
 	for _, proxy = range param.proxy {
 		proxyClient, _, _, err = sshConnect(&sshArgs{Destination: proxy}, proxyClient, proxy)
 		if err != nil {
@@ -1088,7 +1088,7 @@ func sshConnect(args *sshArgs, client sshClient, proxy string) (sshClient, *sshP
 	return proxyConnect(proxyClient, proxy)
 }
 
-func keepAlive(client sshClient, args *sshArgs) {
+func keepAlive(client SshClient, args *sshArgs) {
 	getOptionValue := func(option string) int {
 		value, err := strconv.Atoi(getOptionConfig(args, option))
 		if err != nil {
@@ -1129,7 +1129,7 @@ func keepAlive(client sshClient, args *sshArgs) {
 	}()
 }
 
-func sshAgentForward(args *sshArgs, param *sshParam, client sshClient, session sshSession) {
+func sshAgentForward(args *sshArgs, param *sshParam, client SshClient, session SshSession) {
 	if args.NoForwardAgent || !args.ForwardAgent && strings.ToLower(getOptionConfig(args, "ForwardAgent")) != "yes" {
 		return
 	}

tssh/main.go

@@ -116,9 +116,16 @@ func cleanupAfterLogin() {
 
 var isTerminal bool = isatty.IsTerminal(os.Stdin.Fd()) || isatty.IsCygwinTerminal(os.Stdin.Fd())
 
-func TsshMain() int {
+// TrzMain is the main function of tssh program.
+func TsshMain(argv []string) int {
+	// parse ssh args
 	var args sshArgs
-	parser := arg.MustParse(&args)
+	parser, err := arg.NewParser(arg.Config{Out: os.Stderr, Exit: os.Exit}, &args)
+	if err != nil {
+		fmt.Fprintln(os.Stderr, err)
+		return -1
+	}
+	parser.MustParse(argv)
 
 	// debug log
 	if args.Debug {
@@ -129,7 +136,6 @@ func TsshMain() int {
 	defer cleanupOnExit()
 
 	// print message after stdin reset
-	var err error
 	defer func() {
 		if err != nil {
 			fmt.Fprintf(os.Stderr, "%v\r\n", err)
@@ -149,7 +155,7 @@ func TsshMain() int {
 	}
 
 	// execute local tools if necessary
-	if code, quit := execLocalTools(&args); quit {
+	if code, quit := execLocalTools(argv, &args); quit {
 		return code
 	}