Parse global options

tools/cmd/at/main.go

@@ -1,7 +1,15 @@
 package at
 
 import (
+	"fmt"
+	"io/ioutil"
+	"os"
+	"strings"
+
+	"github.com/mattn/go-isatty"
 	"github.com/spf13/cobra"
+	"golang.org/x/sys/unix"
+	"golang.org/x/term"
 
 	"kitty/tools/cli"
 	"kitty/tools/crypto"
@@ -9,36 +17,100 @@ import (
 
 var encrypt_cmd = crypto.Encrypt_cmd
 
+type GlobalOptions struct {
+	to, password, use_password string
+	to_from_env                bool
+}
+
+var global_options GlobalOptions
+
+func get_password(password string, password_file string, password_env string, use_password string) (string, error) {
+	if use_password == "never" {
+		return "", nil
+	}
+	ans := ""
+	if password != "" {
+		ans = password
+	}
+	if ans == "" && password_file != "" {
+		if password_file == "-" {
+			if isatty.IsTerminal(os.Stdin.Fd()) {
+				q, err := term.ReadPassword(int(os.Stdin.Fd()))
+				if err != nil {
+					ans = string(q)
+				}
+			} else {
+				q, err := ioutil.ReadAll(os.Stdin)
+				if err != nil {
+					ans = strings.TrimRight(string(q), " \n\t")
+				}
+				ttyf, err := os.Open("/dev/tty")
+				if err != nil {
+					err = unix.Dup2(int(ttyf.Fd()), int(os.Stdin.Fd()))
+					ttyf.Close()
+				}
+			}
+		} else {
+			q, err := ioutil.ReadFile(password_file)
+			if err != nil {
+				ans = strings.TrimRight(string(q), " \n\t")
+			}
+		}
+	}
+	if ans == "" && password_env != "" {
+		ans = os.Getenv(password_env)
+	}
+	if ans == "" && use_password == "always" {
+		return ans, fmt.Errorf("No password was found")
+	}
+	if len(ans) > 1024 {
+		return ans, fmt.Errorf("Specified password is too long")
+	}
+	return ans, nil
+}
+
 func EntryPoint(tool_root *cobra.Command) *cobra.Command {
+	var to, password, password_file, password_env, use_password *string
 	var root = cli.CreateCommand(&cobra.Command{
 		Use:   "@ [global options] command [command options] [command args]",
 		Short: "Control kitty remotely",
 		Long:  "Control kitty by sending it commands. Set the allow_remote_control option in :file:`kitty.conf` or use a password, for this to work.",
+		PersistentPreRunE: func(cmd *cobra.Command, args []string) error {
+			if *to == "" {
+				*to = os.Getenv("KITTY_LISTEN_ON")
+				global_options.to_from_env = true
+			}
+			global_options.to = *to
+			global_options.use_password = *use_password
+			q, err := get_password(*password, *password_file, *password_env, *use_password)
+			global_options.password = q
+			return err
+		},
 	})
 	root.Annotations["options_title"] = "Global options"
 
-	root.PersistentFlags().String("to", "",
+	to = root.PersistentFlags().String("to", "",
 		"An address for the kitty instance to control. Corresponds to the address given"+
 			" to the kitty instance via the :option:`kitty --listen-on` option or the :opt:`listen_on` setting in :file:`kitty.conf`. If not"+
-			" specified, the environment variable :env:`KITTY_LISTEN_ON` is checked. If that"+
+			" specified, the environment variable :envvar:`KITTY_LISTEN_ON` is checked. If that"+
 			" is also not found, messages are sent to the controlling terminal for this"+
 			" process, i.e. they will only work if this process is run within a kitty window.")
 
-	root.PersistentFlags().String("password", "",
+	password = root.PersistentFlags().String("password", "",
 		"A password to use when contacting kitty. This will cause kitty to ask the user"+
 			" for permission to perform the specified action, unless the password has been"+
 			" accepted before or is pre-configured in :file:`kitty.conf`.")
 
-	root.PersistentFlags().String("password-file", "rc-pass",
+	password_file = root.PersistentFlags().String("password-file", "rc-pass",
 		"A file from which to read the password. Trailing whitespace is ignored. Relative"+
 			" paths are resolved from the kitty configuration directory. Use - to read from STDIN."+
 			" Used if no :option:`--password` is supplied. Defaults to checking for the"+
 			" :file:`rc-pass` file in the kitty configuration directory.")
 
-	root.PersistentFlags().String("password-env", "KITTY_RC_PASSWORD",
+	password_env = root.PersistentFlags().String("password-env", "KITTY_RC_PASSWORD",
 		"The name of an environment variable to read the password from."+
 			" Used if no :option:`--password-file` or :option:`--password` is supplied.")
 
-	cli.PersistentChoices(root, "use-password", "If no password is available, kitty will usually just send the remote control command without a password. This option can be used to force it to always or never use the supplied password.", "if-available", "always", "never")
+	use_password = cli.PersistentChoices(root, "use-password", "If no password is available, kitty will usually just send the remote control command without a password. This option can be used to force it to always or never use the supplied password.", "if-available", "always", "never")
 	return root
 }

tools/cmd/main.go

@@ -19,7 +19,7 @@ func main() {
 
 	cli.Init(root)
 	if err := root.Execute(); err != nil {
-		fmt.Fprintln(os.Stderr, err)
+		fmt.Fprintln(os.Stderr, "Error:", err)
 		os.Exit(1)
 	}
 }