fix: allow env vars and SSH tokens in IdentityFile validation (issue #33)

ValidateIdentityFile now accepts $VAR/${VAR} (expanded via os.Expand, undefined vars accepted as-is) and SSH tokens like %d, %h before falling back to os.Stat.
The raw value is preserved when writing to ssh_config.

README.md

@@ -268,13 +268,40 @@ sshm move my-server -c /path/to/custom/ssh_config
 # Search for hosts (interactive filter)
 sshm search
 
-# Show version information (includes update check)
+# Print machine-readable info (JSON) for scripting
+sshm info prod-server
+sshm info prod-server --pretty
+
+# With a custom SSH config file
+sshm -c /path/to/custom/ssh_config info prod-server
+
+# Pipe to jq
+sshm info prod-server | jq -r '.result.target.hostname'
+sshm info prod-server | jq -r '.result.target.user'
+
+# Show version information
 sshm --version
 
+# Disable automatic update check (useful on air-gapped machines)
+sshm --no-update-check
+
 # Show help and available commands
 sshm --help
 ```
 
+### Host Info (JSON)
+
+`sshm info <hostname>` prints a single JSON object to stdout so you can script against it with `jq`.
+
+```bash
+# Extract fields
+sshm info prod-server | jq -r '.result.target.hostname'
+sshm info prod-server | jq -r '.result.target.port'
+
+# Check not-found (exit code 2)
+sshm info does-not-exist | jq -r '.error.code'
+```
+
 ### Shell Completion
 
 SSHM supports shell completion for host names, making it easy to connect to hosts without typing full names:
@@ -475,17 +502,31 @@ SSHM features asynchronous SSH connectivity checking that provides visual indica
 SSHM includes built-in version checking that notifies you of available updates:
 
 **Features:**
-- **Background checking** - Version check happens asynchronously
+- **Background checking** - Version check happens asynchronously, never blocking startup
 - **Release notifications** - Clear indicators when updates are available
 - **Pre-release detection** - Identifies beta and development versions
 - **GitHub integration** - Direct links to release pages
 - **Non-intrusive** - Updates don't interrupt your workflow
+- **Configurable** - Can be disabled for air-gapped or offline environments
 
 **Update notifications appear:**
 - In the main TUI interface as a subtle notification
-- In the `sshm --version` command output
 - Only when a newer stable version is available
 
+**Disabling update checks:**
+
+Via the CLI flag (one-time):
+```bash
+sshm --no-update-check
+```
+
+Via `~/.config/sshm/config.json` (persistent):
+```json
+{
+  "check_for_updates": false
+}
+```
+
 #### Port Forwarding History
 
 SSHM remembers your port forwarding configurations for easy reuse:
@@ -639,9 +680,9 @@ This will be automatically converted to:
     StrictHostKeyChecking no
 ```
 
-### Custom Key Bindings
+### Application Configuration
 
-SSHM supports customizable key bindings through a configuration file. This is particularly useful for users who want to modify the default quit behavior.
+SSHM supports a configuration file to customize its behavior, including key bindings and update checking.
 
 **Configuration File Location:**
 - **Linux/macOS**: `~/.config/sshm/config.json`
@@ -650,6 +691,7 @@ SSHM supports customizable key bindings through a configuration file. This is pa
 **Example Configuration:**
 ```json
 {
+  "check_for_updates": false,
   "key_bindings": {
     "quit_keys": ["q", "ctrl+c"],
     "disable_esc_quit": true
@@ -658,12 +700,16 @@ SSHM supports customizable key bindings through a configuration file. This is pa
 ```
 
 **Available Options:**
+- **check_for_updates**: Boolean to enable or disable the automatic update check at startup. Default: `true`. Set to `false` on air-gapped or offline machines to avoid connection delays.
 - **quit_keys**: Array of keys that will quit the application. Default: `["q", "ctrl+c"]`
 - **disable_esc_quit**: Boolean flag to disable ESC key from quitting the application. Default: `false`
 
 **For Vim Users:**
 If you frequently press ESC accidentally causing the application to quit, set `disable_esc_quit` to `true`. This will disable ESC as a quit key while preserving all other functionality.
 
+**For Air-gapped Machines:**
+If SSHM is slow to start due to DNS timeouts when reaching GitHub, set `check_for_updates` to `false`. You can also use the `--no-update-check` CLI flag for a one-time override without editing the config file.
+
 **Default Configuration:**
 If no configuration file exists, SSHM will automatically create one with default settings that maintain backward compatibility.
 

cmd/info.go

@@ -0,0 +1,199 @@
+package cmd
+
+import (
+	"encoding/json"
+	"io"
+	"os"
+	"strconv"
+	"strings"
+
+	"github.com/Gu1llaum-3/sshm/internal/config"
+
+	"github.com/spf13/cobra"
+)
+
+type infoResponse struct {
+	Schema   string      `json:"schema"`
+	OK       bool        `json:"ok"`
+	Hostname string      `json:"hostname"`
+	Result   *infoResult `json:"result"`
+	Error    *infoError  `json:"error"`
+}
+
+type infoResult struct {
+	CanonicalName string      `json:"canonical_name"`
+	Target        infoTarget  `json:"target"`
+	IdentityFile  *string     `json:"identity_file"`
+	ProxyJump     *string     `json:"proxy_jump"`
+	ProxyCommand  *string     `json:"proxy_command"`
+	Options       *string     `json:"options"`
+	Tags          []string    `json:"tags"`
+	RemoteCommand *string     `json:"remote_command"`
+	RequestTTY    *string     `json:"request_tty"`
+	Source        *infoSource `json:"source"`
+}
+
+type infoTarget struct {
+	Host     string  `json:"host"`
+	Hostname *string `json:"hostname"`
+	User     *string `json:"user"`
+	Port     *int    `json:"port"`
+}
+
+type infoSource struct {
+	File string `json:"file"`
+	Line int    `json:"line"`
+}
+
+type infoError struct {
+	Code    string          `json:"code"`
+	Message string          `json:"message"`
+	Details json.RawMessage `json:"details"`
+}
+
+func maybeString(v string) *string {
+	trimmed := strings.TrimSpace(v)
+	if trimmed == "" {
+		return nil
+	}
+	return &trimmed
+}
+
+func maybePort(v string) (*int, error) {
+	trimmed := strings.TrimSpace(v)
+	if trimmed == "" {
+		return nil, nil
+	}
+	port, err := strconv.Atoi(trimmed)
+	if err != nil {
+		return nil, err
+	}
+	return &port, nil
+}
+
+func writeInfoJSON(out io.Writer, pretty bool, resp infoResponse) {
+	var b []byte
+	var err error
+	if pretty {
+		b, err = json.MarshalIndent(resp, "", "  ")
+	} else {
+		b, err = json.Marshal(resp)
+	}
+	if err != nil {
+		_, _ = io.WriteString(out, `{"schema":"sshm.info.v1","ok":false,"hostname":"","result":null,"error":{"code":"INTERNAL","message":"failed to marshal JSON","details":null}}\n`)
+		return
+	}
+	_, _ = out.Write(append(b, '\n'))
+}
+
+func runInfo(out io.Writer, hostnameArg string, cfgFile string, pretty bool) int {
+	resp := infoResponse{
+		Schema:   "sshm.info.v1",
+		OK:       false,
+		Hostname: hostnameArg,
+		Result:   nil,
+		Error:    nil,
+	}
+
+	var host *config.SSHHost
+	var err error
+	if cfgFile != "" {
+		host, err = config.GetSSHHostFromFile(hostnameArg, cfgFile)
+	} else {
+		host, err = config.GetSSHHost(hostnameArg)
+	}
+	if err != nil {
+		code := 1
+		errCode := "CONFIG_ERROR"
+		msg := err.Error()
+		if strings.Contains(msg, "not found") {
+			code = 2
+			errCode = "NOT_FOUND"
+		}
+
+		resp.Error = &infoError{Code: errCode, Message: msg, Details: nil}
+		writeInfoJSON(out, pretty, resp)
+		return code
+	}
+
+	port, portErr := maybePort(host.Port)
+	if portErr != nil {
+		resp.Error = &infoError{Code: "CONFIG_ERROR", Message: "invalid port in host configuration", Details: nil}
+		writeInfoJSON(out, pretty, resp)
+		return 1
+	}
+
+	res := infoResult{
+		CanonicalName: host.Name,
+		Target: infoTarget{
+			Host:     hostnameArg,
+			Hostname: maybeString(host.Hostname),
+			User:     maybeString(host.User),
+			Port:     port,
+		},
+		IdentityFile:  maybeString(host.Identity),
+		ProxyJump:     maybeString(host.ProxyJump),
+		ProxyCommand:  maybeString(host.ProxyCommand),
+		Options:       maybeString(host.Options),
+		Tags:          host.Tags,
+		RemoteCommand: maybeString(host.RemoteCommand),
+		RequestTTY:    maybeString(host.RequestTTY),
+		Source: &infoSource{
+			File: host.SourceFile,
+			Line: host.LineNumber,
+		},
+	}
+
+	resp.OK = true
+	resp.Result = &res
+	writeInfoJSON(out, pretty, resp)
+	return 0
+}
+
+var infoPretty bool
+
+var infoCmd = &cobra.Command{
+	Use:           "info <hostname>",
+	Short:         "Print machine-readable information about a host",
+	Long:          "Print machine-readable information (JSON) about a configured SSH host.",
+	Args:          cobra.ExactArgs(1),
+	SilenceUsage:  true,
+	SilenceErrors: true,
+	ValidArgsFunction: func(cmd *cobra.Command, args []string, toComplete string) ([]string, cobra.ShellCompDirective) {
+		if len(args) != 0 {
+			return nil, cobra.ShellCompDirectiveNoFileComp
+		}
+
+		var hosts []config.SSHHost
+		var err error
+		if configFile != "" {
+			hosts, err = config.ParseSSHConfigFile(configFile)
+		} else {
+			hosts, err = config.ParseSSHConfig()
+		}
+		if err != nil {
+			return nil, cobra.ShellCompDirectiveError
+		}
+
+		var completions []string
+		toCompleteLower := strings.ToLower(toComplete)
+		for _, host := range hosts {
+			if strings.HasPrefix(strings.ToLower(host.Name), toCompleteLower) {
+				completions = append(completions, host.Name)
+			}
+		}
+		return completions, cobra.ShellCompDirectiveNoFileComp
+	},
+	RunE: func(cmd *cobra.Command, args []string) error {
+		exitCode := runInfo(cmd.OutOrStdout(), args[0], configFile, infoPretty)
+		if exitCode != 0 {
+			os.Exit(exitCode)
+		}
+		return nil
+	},
+}
+
+func init() {
+	infoCmd.Flags().BoolVar(&infoPretty, "pretty", false, "Pretty-print JSON output")
+	RootCmd.AddCommand(infoCmd)
+}

cmd/info_test.go

@@ -0,0 +1,321 @@
+package cmd
+
+import (
+	"bytes"
+	"encoding/json"
+	"os"
+	"path/filepath"
+	"strings"
+	"testing"
+
+	"github.com/spf13/cobra"
+)
+
+type infoResponseForTest struct {
+	Schema   string             `json:"schema"`
+	OK       bool               `json:"ok"`
+	Hostname string             `json:"hostname"`
+	Result   *infoResultForTest `json:"result"`
+	Error    *infoErrorForTest  `json:"error"`
+}
+
+type infoResultForTest struct {
+	CanonicalName string             `json:"canonical_name"`
+	Target        infoTargetForTest  `json:"target"`
+	IdentityFile  *string            `json:"identity_file"`
+	ProxyJump     *string            `json:"proxy_jump"`
+	ProxyCommand  *string            `json:"proxy_command"`
+	Options       *string            `json:"options"`
+	Tags          []string           `json:"tags"`
+	RemoteCommand *string            `json:"remote_command"`
+	RequestTTY    *string            `json:"request_tty"`
+	Source        *infoSourceForTest `json:"source"`
+}
+
+type infoTargetForTest struct {
+	Host     string  `json:"host"`
+	Hostname *string `json:"hostname"`
+	User     *string `json:"user"`
+	Port     *int    `json:"port"`
+}
+
+type infoSourceForTest struct {
+	File string `json:"file"`
+	Line int    `json:"line"`
+}
+
+type infoErrorForTest struct {
+	Code    string          `json:"code"`
+	Message string          `json:"message"`
+	Details json.RawMessage `json:"details"`
+}
+
+func TestInfoCommandConfig(t *testing.T) {
+	if infoCmd.Use != "info <hostname>" {
+		t.Fatalf("infoCmd.Use=%q", infoCmd.Use)
+	}
+
+	err := infoCmd.Args(infoCmd, []string{})
+	if err == nil {
+		t.Fatalf("expected args error for no args")
+	}
+
+	err = infoCmd.Args(infoCmd, []string{"one", "two"})
+	if err == nil {
+		t.Fatalf("expected args error for too many args")
+	}
+
+	err = infoCmd.Args(infoCmd, []string{"host"})
+	if err != nil {
+		t.Fatalf("expected no args error, got %v", err)
+	}
+}
+
+func TestInfoCommandRegistration(t *testing.T) {
+	found := false
+	for _, c := range RootCmd.Commands() {
+		if c.Name() == "info" {
+			found = true
+			break
+		}
+	}
+	if !found {
+		t.Fatalf("info command not registered")
+	}
+}
+
+func TestRunInfoSuccessJSON(t *testing.T) {
+	tempDir := t.TempDir()
+	cfg := filepath.Join(tempDir, "config")
+
+	cfgContent := `# Tags: prod, web
+Host prod-web
+    HostName 10.0.0.10
+    User deploy
+    Port 2222
+    IdentityFile ~/.ssh/id_prod
+    ProxyJump bastion
+    ServerAliveInterval 60
+`
+
+	if err := os.WriteFile(cfg, []byte(cfgContent), 0600); err != nil {
+		t.Fatalf("write config: %v", err)
+	}
+
+	buf := new(bytes.Buffer)
+	exitCode := runInfo(buf, "prod-web", cfg, false)
+	if exitCode != 0 {
+		t.Fatalf("exitCode=%d", exitCode)
+	}
+
+	out := buf.String()
+	if strings.TrimSpace(out) == "" {
+		t.Fatalf("expected output")
+	}
+
+	var resp infoResponseForTest
+	if err := json.Unmarshal([]byte(out), &resp); err != nil {
+		t.Fatalf("output not JSON: %v\noutput=%q", err, out)
+	}
+
+	if resp.Schema != "sshm.info.v1" {
+		t.Fatalf("schema=%q", resp.Schema)
+	}
+	if !resp.OK {
+		t.Fatalf("ok=false")
+	}
+	if resp.Result == nil {
+		t.Fatalf("result is nil")
+	}
+	if resp.Error != nil {
+		t.Fatalf("error is non-nil")
+	}
+
+	if resp.Result.CanonicalName != "prod-web" {
+		t.Fatalf("canonical_name=%q", resp.Result.CanonicalName)
+	}
+	if resp.Result.Target.Host != "prod-web" {
+		t.Fatalf("target.host=%q", resp.Result.Target.Host)
+	}
+	if resp.Result.Target.Hostname == nil || *resp.Result.Target.Hostname != "10.0.0.10" {
+		t.Fatalf("target.hostname=%v", resp.Result.Target.Hostname)
+	}
+	if resp.Result.Target.User == nil || *resp.Result.Target.User != "deploy" {
+		t.Fatalf("target.user=%v", resp.Result.Target.User)
+	}
+	if resp.Result.Target.Port == nil || *resp.Result.Target.Port != 2222 {
+		t.Fatalf("target.port=%v", resp.Result.Target.Port)
+	}
+	if resp.Result.Source == nil || resp.Result.Source.File == "" || resp.Result.Source.Line == 0 {
+		t.Fatalf("source missing: %#v", resp.Result.Source)
+	}
+	if resp.Result.IdentityFile == nil || *resp.Result.IdentityFile != "~/.ssh/id_prod" {
+		t.Fatalf("identity_file=%v", resp.Result.IdentityFile)
+	}
+	if resp.Result.ProxyJump == nil || *resp.Result.ProxyJump != "bastion" {
+		t.Fatalf("proxy_jump=%v", resp.Result.ProxyJump)
+	}
+}
+
+func TestRunInfoNotFoundJSON(t *testing.T) {
+	tempDir := t.TempDir()
+	cfg := filepath.Join(tempDir, "config")
+	cfgContent := `Host known
+    HostName example.com
+`
+	if err := os.WriteFile(cfg, []byte(cfgContent), 0600); err != nil {
+		t.Fatalf("write config: %v", err)
+	}
+
+	buf := new(bytes.Buffer)
+	exitCode := runInfo(buf, "missing", cfg, false)
+	if exitCode != 2 {
+		t.Fatalf("exitCode=%d", exitCode)
+	}
+
+	var resp infoResponseForTest
+	if err := json.Unmarshal(buf.Bytes(), &resp); err != nil {
+		t.Fatalf("output not JSON: %v", err)
+	}
+	if resp.OK {
+		t.Fatalf("ok=true")
+	}
+	if resp.Error == nil {
+		t.Fatalf("error is nil")
+	}
+	if resp.Error.Code != "NOT_FOUND" {
+		t.Fatalf("error.code=%q", resp.Error.Code)
+	}
+}
+
+func TestRunInfoPrettyJSON(t *testing.T) {
+	tempDir := t.TempDir()
+	cfg := filepath.Join(tempDir, "config")
+	cfgContent := `Host known
+    HostName 127.0.0.1
+`
+	if err := os.WriteFile(cfg, []byte(cfgContent), 0600); err != nil {
+		t.Fatalf("write config: %v", err)
+	}
+
+	buf := new(bytes.Buffer)
+	exitCode := runInfo(buf, "known", cfg, true)
+	if exitCode != 0 {
+		t.Fatalf("exitCode=%d", exitCode)
+	}
+
+	out := buf.String()
+	if !strings.Contains(out, "\n") {
+		t.Fatalf("expected pretty output")
+	}
+
+	var resp infoResponseForTest
+	if err := json.Unmarshal(buf.Bytes(), &resp); err != nil {
+		t.Fatalf("output not JSON: %v", err)
+	}
+	if !resp.OK {
+		t.Fatalf("ok=false")
+	}
+}
+
+func TestInfoValidArgsFunction(t *testing.T) {
+	if infoCmd.ValidArgsFunction == nil {
+		t.Fatalf("expected ValidArgsFunction to be set on infoCmd")
+	}
+}
+
+func TestInfoValidArgsFunctionWithSSHConfig(t *testing.T) {
+	tmpDir := t.TempDir()
+	testConfigFile := filepath.Join(tmpDir, "config")
+
+	sshConfig := `Host prod-server
+    HostName 192.168.1.1
+    User admin
+
+Host dev-server
+    HostName 192.168.1.2
+    User developer
+
+Host staging-db
+    HostName 192.168.1.3
+    User dbadmin
+`
+	if err := os.WriteFile(testConfigFile, []byte(sshConfig), 0600); err != nil {
+		t.Fatalf("Failed to write test config: %v", err)
+	}
+
+	originalConfigFile := configFile
+	defer func() { configFile = originalConfigFile }()
+	configFile = testConfigFile
+
+	tests := []struct {
+		name       string
+		toComplete string
+		args       []string
+		wantCount  int
+		wantHosts  []string
+	}{
+		{
+			name:       "empty prefix returns all hosts",
+			toComplete: "",
+			args:       []string{},
+			wantCount:  3,
+			wantHosts:  []string{"prod-server", "dev-server", "staging-db"},
+		},
+		{
+			name:       "prefix filters hosts",
+			toComplete: "prod",
+			args:       []string{},
+			wantCount:  1,
+			wantHosts:  []string{"prod-server"},
+		},
+		{
+			name:       "prefix case insensitive",
+			toComplete: "DEV",
+			args:       []string{},
+			wantCount:  1,
+			wantHosts:  []string{"dev-server"},
+		},
+		{
+			name:       "no match returns empty",
+			toComplete: "nonexistent",
+			args:       []string{},
+			wantCount:  0,
+			wantHosts:  []string{},
+		},
+		{
+			name:       "already has host arg returns nothing",
+			toComplete: "",
+			args:       []string{"existing-host"},
+			wantCount:  0,
+			wantHosts:  []string{},
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			completions, directive := infoCmd.ValidArgsFunction(infoCmd, tt.args, tt.toComplete)
+
+			if len(completions) != tt.wantCount {
+				t.Fatalf("Expected %d completions, got %d: %v", tt.wantCount, len(completions), completions)
+			}
+
+			if directive != cobra.ShellCompDirectiveNoFileComp {
+				t.Fatalf("Expected ShellCompDirectiveNoFileComp, got %v", directive)
+			}
+
+			for _, wantHost := range tt.wantHosts {
+				found := false
+				for _, comp := range completions {
+					if comp == wantHost {
+						found = true
+						break
+					}
+				}
+				if !found {
+					t.Fatalf("Expected completion %q not found in %v", wantHost, completions)
+				}
+			}
+		})
+	}
+}

cmd/root.go

@@ -1,19 +1,16 @@
 package cmd
 
 import (
-	"context"
 	"fmt"
 	"log"
 	"os"
 	"os/exec"
 	"strings"
 	"syscall"
-	"time"
 
 	"github.com/Gu1llaum-3/sshm/internal/config"
 	"github.com/Gu1llaum-3/sshm/internal/history"
 	"github.com/Gu1llaum-3/sshm/internal/ui"
-	"github.com/Gu1llaum-3/sshm/internal/version"
 
 	"github.com/spf13/cobra"
 )
@@ -30,6 +27,9 @@ var forceTTY bool
 // searchMode enables the focus on search mode at startup
 var searchMode bool
 
+// noUpdateCheck disables the async update check in the TUI
+var noUpdateCheck bool
+
 // RootCmd is the base command when called without any subcommands
 var RootCmd = &cobra.Command{
 	Use:   "sshm [host] [command...]",
@@ -143,7 +143,7 @@ func runInteractiveMode() {
 	}
 
 	// Run the interactive TUI
-	if err := ui.RunInteractiveMode(hosts, configFile, searchMode, AppVersion); err != nil {
+	if err := ui.RunInteractiveMode(hosts, configFile, searchMode, AppVersion, noUpdateCheck); err != nil {
 		log.Fatalf("Error running interactive mode: %v", err)
 	}
 }
@@ -196,6 +196,15 @@ func connectToHost(hostName string, remoteCommand []string) {
 		fmt.Printf("Connecting to %s...\n", hostName)
 	}
 
+	sshPath, lookErr := exec.LookPath("ssh")
+	if lookErr == nil {
+		argv := append([]string{"ssh"}, args...)
+		// On Unix, Exec replaces the process and never returns on success.
+		// On Windows, Exec is not supported and returns an error; fall through to the exec.Command fallback.
+		_ = syscall.Exec(sshPath, argv, os.Environ())
+	}
+
+	// Fallback for Windows or if LookPath failed
 	sshCmd := exec.Command("ssh", args...)
 	sshCmd.Stdin = os.Stdin
 	sshCmd.Stdout = os.Stdout
@@ -213,30 +222,6 @@ func connectToHost(hostName string, remoteCommand []string) {
 	}
 }
 
-// getVersionWithUpdateCheck returns a custom version string with update check
-func getVersionWithUpdateCheck() string {
-	versionText := fmt.Sprintf("sshm version %s", AppVersion)
-
-	// Check for updates
-	ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
-	defer cancel()
-
-	updateInfo, err := version.CheckForUpdates(ctx, AppVersion)
-	if err != nil {
-		// Return just version if check fails
-		return versionText + "\n"
-	}
-
-	if updateInfo != nil && updateInfo.Available {
-		versionText += fmt.Sprintf("\n🚀 Update available: %s → %s (%s)",
-			updateInfo.CurrentVer,
-			updateInfo.LatestVer,
-			updateInfo.ReleaseURL)
-	}
-
-	return versionText + "\n"
-}
-
 // Execute adds all child commands to the root command and sets flags appropriately.
 func Execute() {
 	if err := RootCmd.Execute(); err != nil {
@@ -258,7 +243,7 @@ func init() {
 	RootCmd.PersistentFlags().StringVarP(&configFile, "config", "c", "", "SSH config file to use (default: ~/.ssh/config)")
 	RootCmd.Flags().BoolVarP(&forceTTY, "tty", "t", false, "Force pseudo-TTY allocation (useful for interactive remote commands)")
 	RootCmd.PersistentFlags().BoolVarP(&searchMode, "search", "s", false, "Focus on search input at startup")
+	RootCmd.PersistentFlags().BoolVar(&noUpdateCheck, "no-update-check", false, "Disable automatic update check")
 
-	// Set custom version template with update check
-	RootCmd.SetVersionTemplate(getVersionWithUpdateCheck())
+	RootCmd.SetVersionTemplate("{{.Name}} version {{.Version}}\n")
 }

cmd/root_test.go

@@ -45,7 +45,7 @@ func TestRootCommandFlags(t *testing.T) {
 func TestRootCommandSubcommands(t *testing.T) {
 	// Test that all expected subcommands are registered
 	// Note: completion and help are automatically added by Cobra and may not always appear in Commands()
-	expectedCommands := []string{"add", "edit", "search"}
+	expectedCommands := []string{"add", "edit", "search", "info"}
 
 	commands := RootCmd.Commands()
 	commandNames := make(map[string]bool)

internal/config/appconfig.go

@@ -18,9 +18,18 @@ type KeyBindings struct {
 
 // AppConfig represents the main application configuration
 type AppConfig struct {
+	CheckForUpdates *bool       `json:"check_for_updates,omitempty"`
 	KeyBindings     KeyBindings `json:"key_bindings"`
 }
 
+// IsUpdateCheckEnabled returns true if the update check is enabled (default: true)
+func (c *AppConfig) IsUpdateCheckEnabled() bool {
+	if c == nil || c.CheckForUpdates == nil {
+		return true
+	}
+	return *c.CheckForUpdates
+}
+
 // GetDefaultKeyBindings returns the default key bindings configuration
 func GetDefaultKeyBindings() KeyBindings {
 	return KeyBindings{

internal/config/appconfig_test.go

@@ -104,6 +104,58 @@ func TestAppConfigBasics(t *testing.T) {
 	if len(defaultConfig.KeyBindings.QuitKeys) != len(expectedQuitKeys) {
 		t.Errorf("Expected %d quit keys, got %d", len(expectedQuitKeys), len(defaultConfig.KeyBindings.QuitKeys))
 	}
+
+	// CheckForUpdates should be nil by default
+	if defaultConfig.CheckForUpdates != nil {
+		t.Error("Default configuration should have CheckForUpdates as nil")
+	}
+
+	// IsUpdateCheckEnabled should return true by default
+	if !defaultConfig.IsUpdateCheckEnabled() {
+		t.Error("IsUpdateCheckEnabled should return true when CheckForUpdates is nil")
+	}
+}
+
+func boolPtr(b bool) *bool {
+	return &b
+}
+
+func TestIsUpdateCheckEnabled(t *testing.T) {
+	tests := []struct {
+		name     string
+		config   *AppConfig
+		expected bool
+	}{
+		{
+			name:     "nil AppConfig returns true",
+			config:   nil,
+			expected: true,
+		},
+		{
+			name:     "CheckForUpdates nil returns true",
+			config:   &AppConfig{},
+			expected: true,
+		},
+		{
+			name:     "CheckForUpdates true returns true",
+			config:   &AppConfig{CheckForUpdates: boolPtr(true)},
+			expected: true,
+		},
+		{
+			name:     "CheckForUpdates false returns false",
+			config:   &AppConfig{CheckForUpdates: boolPtr(false)},
+			expected: false,
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			result := tt.config.IsUpdateCheckEnabled()
+			if result != tt.expected {
+				t.Errorf("IsUpdateCheckEnabled() = %v, expected %v", result, tt.expected)
+			}
+		})
+	}
 }
 
 func TestMergeWithDefaults(t *testing.T) {
@@ -141,6 +193,7 @@ func TestSaveAndLoadAppConfigIntegration(t *testing.T) {
 	configPath := filepath.Join(tempDir, "config.json")
 
 	customConfig := AppConfig{
+		CheckForUpdates: boolPtr(false),
 		KeyBindings: KeyBindings{
 			QuitKeys:       []string{"q"},
 			DisableEscQuit: true,
@@ -178,4 +231,15 @@ func TestSaveAndLoadAppConfigIntegration(t *testing.T) {
 	if len(loadedConfig.KeyBindings.QuitKeys) != 1 || loadedConfig.KeyBindings.QuitKeys[0] != "q" {
 		t.Errorf("Expected quit keys to be ['q'], got %v", loadedConfig.KeyBindings.QuitKeys)
 	}
+
+	// Verify CheckForUpdates is correctly persisted and reloaded
+	if loadedConfig.CheckForUpdates == nil {
+		t.Fatal("CheckForUpdates should not be nil after round-trip")
+	}
+	if *loadedConfig.CheckForUpdates != false {
+		t.Errorf("CheckForUpdates should be false after round-trip, got %v", *loadedConfig.CheckForUpdates)
+	}
+	if loadedConfig.IsUpdateCheckEnabled() {
+		t.Error("IsUpdateCheckEnabled should return false when CheckForUpdates is false")
+	}
 }

internal/config/ssh.go

@@ -11,6 +11,18 @@ import (
 	"sync"
 )
 
+func getHomeDir() (string, error) {
+	home := os.Getenv("HOME")
+	if home != "" {
+		return home, nil
+	}
+	home = os.Getenv("USERPROFILE")
+	if home != "" {
+		return home, nil
+	}
+	return os.UserHomeDir()
+}
+
 // SSHHost represents an SSH host configuration
 type SSHHost struct {
 	Name          string
@@ -33,7 +45,7 @@ type SSHHost struct {
 
 // GetDefaultSSHConfigPath returns the default SSH config path for the current platform
 func GetDefaultSSHConfigPath() (string, error) {
-	homeDir, err := os.UserHomeDir()
+	homeDir, err := getHomeDir()
 	if err != nil {
 		return "", err
 	}
@@ -49,7 +61,7 @@ func GetDefaultSSHConfigPath() (string, error) {
 
 // GetSSHMConfigDir returns the SSHM config directory
 func GetSSHMConfigDir() (string, error) {
-	homeDir, err := os.UserHomeDir()
+	homeDir, err := getHomeDir()
 	if err != nil {
 		return "", err
 	}
@@ -88,7 +100,7 @@ func GetSSHMBackupDir() (string, error) {
 
 // GetSSHDirectory returns the .ssh directory path
 func GetSSHDirectory() (string, error) {
-	homeDir, err := os.UserHomeDir()
+	homeDir, err := getHomeDir()
 	if err != nil {
 		return "", err
 	}
@@ -386,7 +398,7 @@ func parseSSHConfigFileWithProcessedFiles(configPath string, processedFiles map[
 func processIncludeDirective(pattern string, baseConfigPath string, processedFiles map[string]bool) ([]SSHHost, error) {
 	// Expand tilde to home directory
 	if strings.HasPrefix(pattern, "~") {
-		homeDir, err := os.UserHomeDir()
+		homeDir, err := getHomeDir()
 		if err != nil {
 			return nil, fmt.Errorf("failed to get home directory: %w", err)
 		}
@@ -918,7 +930,7 @@ func quickHostSearchInFile(hostName string, configPath string, processedFiles ma
 func quickSearchInclude(hostName, pattern, baseConfigPath string, processedFiles map[string]bool) (bool, error) {
 	// Expand tilde to home directory
 	if strings.HasPrefix(pattern, "~") {
-		homeDir, err := os.UserHomeDir()
+		homeDir, err := getHomeDir()
 		if err != nil {
 			return false, fmt.Errorf("failed to get home directory: %w", err)
 		}

internal/config/ssh_test.go

@@ -456,15 +456,21 @@ func TestBackupConfigToSSHMDirectory(t *testing.T) {
 	// Create temporary directory for test files
 	tempDir := t.TempDir()
 
-	// Override the home directory for this test
 	originalHome := os.Getenv("HOME")
 	if originalHome == "" {
-		originalHome = os.Getenv("USERPROFILE") // Windows
+		originalHome = os.Getenv("USERPROFILE")
 	}
+	originalXDG := os.Getenv("XDG_CONFIG_HOME")
+	originalAppData := os.Getenv("APPDATA")
 
-	// Set test home directory
 	os.Setenv("HOME", tempDir)
-	defer os.Setenv("HOME", originalHome)
+	os.Setenv("XDG_CONFIG_HOME", tempDir)
+	os.Setenv("APPDATA", tempDir)
+	defer func() {
+		os.Setenv("HOME", originalHome)
+		os.Setenv("XDG_CONFIG_HOME", originalXDG)
+		os.Setenv("APPDATA", originalAppData)
+	}()
 
 	// Create a test SSH config file
 	sshDir := filepath.Join(tempDir, ".ssh")

internal/connectivity/ping.go

@@ -2,12 +2,15 @@ package connectivity
 
 import (
 	"context"
+	"fmt"
 	"net"
-	"github.com/Gu1llaum-3/sshm/internal/config"
+	"os/exec"
 	"strings"
 	"sync"
 	"time"
 
+	"github.com/Gu1llaum-3/sshm/internal/config"
+
 	"golang.org/x/crypto/ssh"
 )
 
@@ -48,13 +51,15 @@ type PingManager struct {
 	results    map[string]*HostPingResult
 	mutex      sync.RWMutex
 	timeout    time.Duration
+	configFile string
 }
 
 // NewPingManager creates a new ping manager with the specified timeout
-func NewPingManager(timeout time.Duration) *PingManager {
+func NewPingManager(timeout time.Duration, configFile string) *PingManager {
 	return &PingManager{
 		results:    make(map[string]*HostPingResult),
 		timeout:    timeout,
+		configFile: configFile,
 	}
 }
 
@@ -98,6 +103,14 @@ func (pm *PingManager) PingHost(ctx context.Context, host config.SSHHost) *HostP
 	// Mark as connecting
 	pm.updateStatus(host.Name, StatusConnecting, nil, 0)
 
+	// If the host uses a ProxyJump or ProxyCommand, we need to use the external SSH command
+	// because implementing jump host support with pure Go ssh library requires
+	// handling authentication for the jump host, which is complex and requires
+	// access to the user's SSH agent or keys.
+	if host.ProxyJump != "" || host.ProxyCommand != "" {
+		return pm.pingWithExternalCommand(ctx, host, start)
+	}
+
 	// Determine the actual hostname and port
 	hostname := host.Hostname
 	if hostname == "" {
@@ -159,6 +172,53 @@ func (pm *PingManager) PingHost(ctx context.Context, host config.SSHHost) *HostP
 	}
 }
 
+// pingWithExternalCommand pings a host using the external SSH command
+func (pm *PingManager) pingWithExternalCommand(ctx context.Context, host config.SSHHost, start time.Time) *HostPingResult {
+	// Construct the SSH command
+	// ssh -q -o BatchMode=yes -o StrictHostKeyChecking=no -o ConnectTimeout=5 host exit
+	args := []string{"-q", "-o", "BatchMode=yes", "-o", "StrictHostKeyChecking=no"}
+
+	// Set timeout matching the manager's timeout
+	// Convert duration to seconds (rounding up to ensure we don't timeout too early in the command)
+	timeoutSec := int(pm.timeout.Seconds())
+	if timeoutSec < 1 {
+		timeoutSec = 1
+	}
+	args = append(args, "-o", fmt.Sprintf("ConnectTimeout=%d", timeoutSec))
+
+	// If we have a specific config file, use it
+	if pm.configFile != "" {
+		args = append(args, "-F", pm.configFile)
+	}
+
+	// Add the host name and the command to run (exit)
+	args = append(args, host.Name, "exit")
+
+	// Create command with context for timeout cancellation
+	// Note: We used pm.timeout for the ssh command option, but we also respect the context deadline
+	cmd := exec.CommandContext(ctx, "ssh", args...)
+
+	// Run the command
+	err := cmd.Run()
+	duration := time.Since(start)
+
+	var status PingStatus
+	if err != nil {
+		// SSH returns non-zero exit code on connection failure
+		status = StatusOffline
+	} else {
+		status = StatusOnline
+	}
+
+	pm.updateStatus(host.Name, status, err, duration)
+	return &HostPingResult{
+		HostName: host.Name,
+		Status:   status,
+		Error:    err,
+		Duration: duration,
+	}
+}
+
 // PingAllHosts pings all hosts concurrently and returns a channel of results
 func (pm *PingManager) PingAllHosts(ctx context.Context, hosts []config.SSHHost) <-chan *HostPingResult {
 	resultChan := make(chan *HostPingResult, len(hosts))

internal/connectivity/ping_test.go

@@ -9,7 +9,7 @@ import (
 )
 
 func TestNewPingManager(t *testing.T) {
-	pm := NewPingManager(5 * time.Second)
+	pm := NewPingManager(5*time.Second, "")
 	if pm == nil {
 		t.Error("NewPingManager() returned nil")
 	}
@@ -19,7 +19,7 @@ func TestNewPingManager(t *testing.T) {
 }
 
 func TestPingManager_PingHost(t *testing.T) {
-	pm := NewPingManager(1 * time.Second)
+	pm := NewPingManager(1*time.Second, "")
 	ctx := context.Background()
 
 	// Test ping method exists and doesn't panic
@@ -38,7 +38,7 @@ func TestPingManager_PingHost(t *testing.T) {
 }
 
 func TestPingManager_GetStatus(t *testing.T) {
-	pm := NewPingManager(1 * time.Second)
+	pm := NewPingManager(1*time.Second, "")
 
 	// Test unknown host
 	status := pm.GetStatus("unknown.host")
@@ -57,7 +57,7 @@ func TestPingManager_GetStatus(t *testing.T) {
 }
 
 func TestPingManager_PingMultipleHosts(t *testing.T) {
-	pm := NewPingManager(1 * time.Second)
+	pm := NewPingManager(1*time.Second, "")
 	hosts := []config.SSHHost{
 		{Name: "localhost", Hostname: "127.0.0.1", Port: "22"},
 		{Name: "invalid", Hostname: "invalid.host.12345", Port: "22"},
@@ -81,7 +81,7 @@ func TestPingManager_PingMultipleHosts(t *testing.T) {
 }
 
 func TestPingManager_GetResult(t *testing.T) {
-	pm := NewPingManager(1 * time.Second)
+	pm := NewPingManager(1*time.Second, "")
 	ctx := context.Background()
 
 	// Test getting result for unknown host
@@ -126,7 +126,7 @@ func TestPingStatus_String(t *testing.T) {
 
 func TestPingHost_Basic(t *testing.T) {
 	// Test that the ping functionality exists
-	pm := NewPingManager(1 * time.Second)
+	pm := NewPingManager(1*time.Second, "")
 	ctx := context.Background()
 	host := config.SSHHost{Name: "test", Hostname: "127.0.0.1", Port: "22"}
 

internal/ui/tui.go

@@ -16,7 +16,7 @@ import (
 )
 
 // NewModel creates a new TUI model with the given SSH hosts
-func NewModel(hosts []config.SSHHost, configFile string, searchMode bool, currentVersion string) Model {
+func NewModel(hosts []config.SSHHost, configFile string, searchMode bool, currentVersion string, noUpdateCheck bool) Model {
 	// Load application configuration
 	appConfig, err := config.LoadAppConfig()
 	if err != nil {
@@ -26,6 +26,12 @@ func NewModel(hosts []config.SSHHost, configFile string, searchMode bool, curren
 		appConfig = &defaultConfig
 	}
 
+	// CLI flag overrides config file setting
+	if noUpdateCheck {
+		f := false
+		appConfig.CheckForUpdates = &f
+	}
+
 	// Initialize the history manager
 	historyManager, err := history.NewHistoryManager()
 	if err != nil {
@@ -38,7 +44,7 @@ func NewModel(hosts []config.SSHHost, configFile string, searchMode bool, curren
 	styles := NewStyles(80) // Default width
 
 	// Initialize ping manager with 5 second timeout
-	pingManager := connectivity.NewPingManager(5 * time.Second)
+	pingManager := connectivity.NewPingManager(5*time.Second, configFile)
 
 	// Create the model with default sorting by name
 	m := Model{
@@ -151,8 +157,8 @@ func NewModel(hosts []config.SSHHost, configFile string, searchMode bool, curren
 }
 
 // RunInteractiveMode starts the interactive TUI interface
-func RunInteractiveMode(hosts []config.SSHHost, configFile string, searchMode bool, currentVersion string) error {
-	m := NewModel(hosts, configFile, searchMode, currentVersion)
+func RunInteractiveMode(hosts []config.SSHHost, configFile string, searchMode bool, currentVersion string, noUpdateCheck bool) error {
+	m := NewModel(hosts, configFile, searchMode, currentVersion, noUpdateCheck)
 
 	// Start the application in alt screen mode for clean output
 	p := tea.NewProgram(m, tea.WithAltScreen())

internal/ui/update.go

@@ -74,8 +74,8 @@ func (m Model) Init() tea.Cmd {
 	// Basic initialization commands
 	cmds = append(cmds, textinput.Blink)
 
-	// Check for version updates if we have a current version
-	if m.currentVersion != "" {
+	// Check for version updates if we have a current version and updates are enabled
+	if m.currentVersion != "" && m.appConfig.IsUpdateCheckEnabled() {
 		cmds = append(cmds, checkVersionCmd(m.currentVersion))
 	}
 

internal/validation/ssh.go

@@ -66,6 +66,25 @@ func ValidateIdentityFile(path string) bool {
 	if path == "" {
 		return true // Optional field
 	}
+	// SSH tokens (e.g. %d, %h, %r, %u) are resolved by SSH at connection time
+	sshTokenRegex := regexp.MustCompile(`%[hprunCdiklLT]`)
+	if sshTokenRegex.MatchString(path) {
+		return true
+	}
+	// Expand environment variables ($VAR and ${VAR}); track undefined ones
+	hasUndefined := false
+	path = os.Expand(path, func(key string) string {
+		val, ok := os.LookupEnv(key)
+		if !ok {
+			hasUndefined = true
+			return "$" + key
+		}
+		return val
+	})
+	// If any variable was undefined, accept the path (SSH will report the error)
+	if hasUndefined {
+		return true
+	}
 	// Expand ~ to home directory
 	if strings.HasPrefix(path, "~/") {
 		homeDir, err := os.UserHomeDir()

internal/validation/ssh_test.go

@@ -133,6 +133,9 @@ func TestValidateIdentityFile(t *testing.T) {
 		t.Fatal(err)
 	}
 
+	// Set up an env var pointing to the valid file's directory for env var tests
+	t.Setenv("TEST_SSHM_DIR", tmpDir)
+
 	tests := []struct {
 		name string
 		path string
@@ -143,6 +146,13 @@ func TestValidateIdentityFile(t *testing.T) {
 		{"non-existent file", "/path/to/nonexistent", false},
 		// Skip tilde path test in CI environments where ~/.ssh/id_rsa may not exist
 		// {"tilde path", "~/.ssh/id_rsa", true}, // Will pass if file exists
+		// Environment variable expansion (issue #33)
+		{"env var $VAR/key defined", "$TEST_SSHM_DIR/test_key", true},
+		{"env var ${VAR}/key defined", "${TEST_SSHM_DIR}/test_key", true},
+		{"env var undefined", "$UNDEFINED_SSHM_VAR_XYZ/key", true},
+		// SSH tokens
+		{"SSH token %d", "%d/.ssh/id_rsa", true},
+		{"SSH token %h", "%h-key", true},
 	}
 
 	for _, tt := range tests {
@@ -170,6 +180,7 @@ func TestValidateHost(t *testing.T) {
 	if err := os.WriteFile(validIdentity, []byte("test"), 0600); err != nil {
 		t.Fatal(err)
 	}
+	t.Setenv("TEST_SSHM_HOST_DIR", tmpDir)
 
 	tests := []struct {
 		name     string
@@ -187,6 +198,9 @@ func TestValidateHost(t *testing.T) {
 		{"invalid hostname", "myserver", "invalid..hostname", "22", "", true},
 		{"invalid port", "myserver", "example.com", "99999", "", true},
 		{"invalid identity", "myserver", "example.com", "22", "/nonexistent", true},
+		// Environment variables and SSH tokens in identity (issue #33)
+		{"identity with env var", "myserver", "example.com", "22", "$TEST_SSHM_HOST_DIR/test_key", false},
+		{"identity with SSH token", "myserver", "example.com", "22", "%d/.ssh/id_rsa", false},
 	}
 
 	for _, tt := range tests {