Work on outputting help for commands

tools/cli/help.go

@@ -0,0 +1,142 @@
+// License: GPLv3 Copyright: 2022, Kovid Goyal, <kovid at kovidgoyal.net>
+
+package cli
+
+import (
+	"fmt"
+	"io"
+	"os"
+	"os/exec"
+	"strings"
+
+	"golang.org/x/sys/unix"
+
+	"kitty"
+	"kitty/tools/cli/markup"
+	"kitty/tools/tty"
+	"kitty/tools/utils/style"
+)
+
+var _ = fmt.Print
+
+func ShowError(err error) {
+	formatter := markup.New(tty.IsTerminal(os.Stderr.Fd()))
+	msg := formatter.Prettify(err.Error())
+	fmt.Fprintln(os.Stderr, formatter.Err("Error")+":", msg)
+}
+
+func (self *Command) ShowVersion() {
+	formatter := markup.New(tty.IsTerminal(os.Stdout.Fd()))
+	fmt.Fprintln(os.Stdout, formatter.Italic(self.CommandStringForUsage()), formatter.Opt(kitty.VersionString), "created by", formatter.Title("Kovid Goyal"))
+}
+
+func format_with_indent(output io.Writer, text string, indent string, screen_width int) {
+	text = formatter.Prettify(text)
+	indented := style.WrapText(text, indent, screen_width, "#placeholder_for_formatting#")
+	io.WriteString(output, indented)
+}
+
+func (self *Command) FormatSubCommands(output io.Writer, formatter *markup.Context, screen_width int) {
+	for _, g := range self.SubCommandGroups {
+		if !g.HasVisibleSubCommands() {
+			continue
+		}
+		fmt.Fprintln(output)
+		if g.Title != "" {
+			fmt.Fprintln(output, formatter.Title(g.Title))
+		}
+		for _, c := range g.SubCommands {
+			if c.Hidden {
+				continue
+			}
+			fmt.Fprintln(output, "  ", formatter.Opt(c.Name))
+			format_with_indent(output, formatter.Prettify(c.ShortDescription), "    ", screen_width)
+		}
+	}
+
+}
+
+func (self *Option) FormatOption(output io.Writer, formatter *markup.Context, screen_width int) {
+	for i, a := range self.Aliases {
+		fmt.Fprint(output, formatter.Opt(a.String()))
+		if i != len(self.Aliases)-1 {
+			fmt.Fprint(output, ", ")
+		}
+	}
+	defval := ""
+	switch self.OptionType {
+	case BoolOption:
+	default:
+		defval = self.Default
+		fallthrough
+	case StringOption:
+		if self.IsList {
+			defval = ""
+		}
+	}
+	if defval != "" {
+		fmt.Fprintf(output, " [=%s]", formatter.Italic(defval))
+	}
+	fmt.Fprintln(output)
+	format_with_indent(output, formatter.Prettify(prepare_help_text_for_display(self.Help)), "    ", screen_width)
+}
+
+func (self *Command) ShowHelp() {
+	formatter := markup.New(tty.IsTerminal(os.Stdout.Fd()))
+	screen_width := 80
+	if formatter.EscapeCodesAllowed() {
+		var sz *unix.Winsize
+		var tty_size_err error
+		for {
+			sz, tty_size_err = unix.IoctlGetWinsize(int(os.Stdout.Fd()), unix.TIOCGWINSZ)
+			if tty_size_err != unix.EINTR {
+				break
+			}
+		}
+		if tty_size_err == nil && sz.Col < 80 {
+			screen_width = int(sz.Col)
+		}
+	}
+	var output strings.Builder
+
+	fmt.Fprintln(&output, formatter.Title("Usage")+":", formatter.Exe(strings.TrimSpace(self.CommandStringForUsage())),
+		strings.TrimSpace(formatter.Prettify(self.Usage)))
+	fmt.Fprintln(&output)
+	format_with_indent(&output, formatter.Prettify(prepare_help_text_for_display(self.HelpText)), "", screen_width)
+
+	if self.HasVisibleSubCommands() {
+		fmt.Fprintln(&output)
+		fmt.Fprintln(&output, formatter.Title("Commands")+":")
+		self.FormatSubCommands(&output, formatter, screen_width)
+		fmt.Fprintln(&output)
+		format_with_indent(&output, "Get help for an individual command by running:", "", screen_width)
+		fmt.Fprintln(&output, "   ", strings.TrimSpace(self.CommandStringForUsage()), formatter.Italic("command"), "-h")
+	}
+
+	group_titles, gmap := self.GetVisibleOptions()
+	if len(group_titles) > 0 {
+		fmt.Fprintln(&output)
+		fmt.Fprintln(&output, formatter.Title("Options")+":")
+		for _, title := range group_titles {
+			fmt.Fprintln(&output)
+			if title != "" {
+				fmt.Fprintln(&output, formatter.Title(title))
+			}
+			for _, opt := range gmap[title] {
+				opt.FormatOption(&output, formatter, screen_width)
+				fmt.Fprintln(&output)
+			}
+		}
+	}
+	output_text := output.String()
+	// fmt.Printf("%#v\n", output_text)
+	if formatter.EscapeCodesAllowed() {
+		pager := exec.Command(kitty.DefaultPager[0], kitty.DefaultPager[1:]...)
+		pager.Stdin = strings.NewReader(output_text)
+		pager.Stdout = os.Stdout
+		pager.Stderr = os.Stderr
+		pager.Run()
+	} else {
+		os.Stdout.Write([]byte(output_text))
+	}
+}