Handle invalid args and passthrough

tools/cmd/ssh/main.go

@@ -3,9 +3,15 @@
 package ssh
 
 import (
+	"errors"
 	"fmt"
+	"os"
+	"strings"
 
 	"kitty/tools/cli"
+
+	"golang.org/x/exp/maps"
+	"golang.org/x/sys/unix"
 )
 
 var _ = fmt.Print
@@ -20,6 +26,27 @@ func main(cmd *cli.Command, o *Options, args []string) (rc int, err error) {
 			return
 		}
 	}
+	ssh_args, server_args, passthrough, found_extra_args, err := ParseSSHArgs(args, "--kitten")
+	if err != nil {
+		var invargs *ErrInvalidSSHArgs
+		switch {
+		case errors.As(err, &invargs):
+			if invargs.Msg != "" {
+				fmt.Fprintln(os.Stderr, invargs.Msg)
+			}
+			return 1, unix.Exec(ssh_exe(), []string{"ssh"}, os.Environ())
+		}
+		return 1, err
+	}
+	if passthrough {
+		if len(found_extra_args) > 0 {
+			return 1, fmt.Errorf("The SSH kitten cannot work with the options: %s", strings.Join(maps.Keys(PassthroughArgs()), " "))
+		}
+		return 1, unix.Exec(ssh_exe(), append([]string{"ssh"}, args...), os.Environ())
+	}
+	if false {
+		return len(ssh_args) + len(server_args), nil
+	}
 	return
 }
 

tools/cmd/ssh/utils.go

@@ -16,6 +16,18 @@ var _ = fmt.Print
 var ssh_options map[string]string
 var query_ssh_for_options_once sync.Once
 
+func ssh_exe() string {
+	ans := utils.Which("ssh")
+	if ans != "" {
+		return ans
+	}
+	ans = utils.Which("ssh", "/usr/local/bin", "/opt/bin", "/opt/homebrew/bin", "/usr/bin", "/bin")
+	if ans == "" {
+		ans = "ssh"
+	}
+	return ans
+}
+
 func get_ssh_options() {
 	defer func() {
 		if ssh_options == nil {
@@ -30,7 +42,7 @@ func get_ssh_options() {
 			}
 		}
 	}()
-	cmd := exec.Command("ssh")
+	cmd := exec.Command(ssh_exe())
 	stderr, err := cmd.StderrPipe()
 	if err != nil {
 		return
@@ -111,6 +123,10 @@ func (self *ErrInvalidSSHArgs) Error() string {
 	return self.Msg
 }
 
+func PassthroughArgs() map[string]bool {
+	return map[string]bool{"-N": true, "-n": true, "-f": true, "-G": true, "-T": true}
+}
+
 func ParseSSHArgs(args []string, extra_args ...string) (ssh_args []string, server_args []string, passthrough bool, found_extra_args []string, err error) {
 	if extra_args == nil {
 		extra_args = []string{}
@@ -119,7 +135,7 @@ func ParseSSHArgs(args []string, extra_args ...string) (ssh_args []string, serve
 		passthrough = true
 		return
 	}
-	passthrough_args := map[string]bool{"-N": true, "-n": true, "-f": true, "-G": true, "-T": true}
+	passthrough_args := PassthroughArgs()
 	boolean_ssh_args, other_ssh_args := GetSSHCLI()
 	ssh_args, server_args, found_extra_args = make([]string, 0, 16), make([]string, 0, 16), make([]string, 0, 16)
 	expecting_option_val := false
@@ -184,8 +200,8 @@ func ParseSSHArgs(args []string, extra_args ...string) (ssh_args []string, serve
 		}
 		server_args = append(server_args, argument)
 	}
-	if len(server_args) == 0 {
-		err = &ErrInvalidSSHArgs{Msg: "No server to connect to specified"}
+	if len(server_args) == 0 && !passthrough {
+		err = &ErrInvalidSSHArgs{Msg: ""}
 	}
 	return
 }