add go build flags

helpmessage/message.go

@@ -1,4 +1,4 @@
-package main
+package helpmessage
 
 import (
 	"bufio"
@@ -11,7 +11,6 @@ import (
 	"unicode/utf8"
 
 	"github.com/jessevdk/go-flags"
-	"golang.org/x/sys/unix"
 )
 
 const (
@@ -40,7 +39,7 @@ type Options struct {
 	options []*Option
 }
 
-func scanStruct(realval reflect.Value, opt *Options) error {
+func ScanStruct(realval reflect.Value, opt *Options) error {
 
 	stype := realval.Type()
 
@@ -144,14 +143,6 @@ func getAlignmentInfo(options *Options, p *flags.Parser) alignmentInfo {
 	return ret
 }
 
-func getTerminalColumns() int {
-	ws, err := unix.IoctlGetWinsize(0, unix.TIOCGWINSZ)
-	if err != nil {
-		return 80
-	}
-	return int(ws.Col)
-}
-
 type alignmentInfo struct {
 	maxLongLen      int
 	hasShort        bool

helpmessage/termsize.go

@@ -0,0 +1,16 @@
+//go:build !windows && !plan9 && !appengine && !wasm
+// +build !windows,!plan9,!appengine,!wasm
+
+package helpmessage
+
+import (
+	"golang.org/x/sys/unix"
+)
+
+func getTerminalColumns() int {
+	ws, err := unix.IoctlGetWinsize(0, unix.TIOCGWINSZ)
+	if err != nil {
+		return 80
+	}
+	return int(ws.Col)
+}

helpmessage/termsize_nosysioctl.go

@@ -0,0 +1,8 @@
+//go:build plan9 || appengine || wasm
+// +build plan9 appengine wasm
+
+package helpmessage
+
+func getTerminalColumns() int {
+	return 80
+}

helpmessage/termsize_windows.go

@@ -0,0 +1,86 @@
+//go:build windows
+// +build windows
+
+package helpmessage
+
+import (
+	"syscall"
+	"unsafe"
+)
+
+type (
+	SHORT int16
+	WORD  uint16
+
+	SMALL_RECT struct {
+		Left   SHORT
+		Top    SHORT
+		Right  SHORT
+		Bottom SHORT
+	}
+
+	COORD struct {
+		X SHORT
+		Y SHORT
+	}
+
+	CONSOLE_SCREEN_BUFFER_INFO struct {
+		Size              COORD
+		CursorPosition    COORD
+		Attributes        WORD
+		Window            SMALL_RECT
+		MaximumWindowSize COORD
+	}
+)
+
+var kernel32DLL = syscall.NewLazyDLL("kernel32.dll")
+var getConsoleScreenBufferInfoProc = kernel32DLL.NewProc("GetConsoleScreenBufferInfo")
+
+func getError(r1, r2 uintptr, lastErr error) error {
+	// If the function fails, the return value is zero.
+	if r1 == 0 {
+		if lastErr != nil {
+			return lastErr
+		}
+		return syscall.EINVAL
+	}
+	return nil
+}
+
+func getStdHandle(stdhandle int) (uintptr, error) {
+	handle, err := syscall.GetStdHandle(stdhandle)
+	if err != nil {
+		return 0, err
+	}
+	return uintptr(handle), nil
+}
+
+// GetConsoleScreenBufferInfo retrieves information about the specified console screen buffer.
+// http://msdn.microsoft.com/en-us/library/windows/desktop/ms683171(v=vs.85).aspx
+func GetConsoleScreenBufferInfo(handle uintptr) (*CONSOLE_SCREEN_BUFFER_INFO, error) {
+	var info CONSOLE_SCREEN_BUFFER_INFO
+	if err := getError(getConsoleScreenBufferInfoProc.Call(handle, uintptr(unsafe.Pointer(&info)), 0)); err != nil {
+		return nil, err
+	}
+	return &info, nil
+}
+
+func getTerminalColumns() int {
+	defaultWidth := 80
+
+	stdoutHandle, err := getStdHandle(syscall.STD_OUTPUT_HANDLE)
+	if err != nil {
+		return defaultWidth
+	}
+
+	info, err := GetConsoleScreenBufferInfo(stdoutHandle)
+	if err != nil {
+		return defaultWidth
+	}
+
+	if info.MaximumWindowSize.X > 0 {
+		return int(info.MaximumWindowSize.X)
+	}
+
+	return defaultWidth
+}

main.go

@@ -20,6 +20,7 @@ import (
 	"github.com/lightninglabs/lndclient"
 	"github.com/lightningnetwork/lnd/lnrpc"
 	"github.com/lightningnetwork/lnd/lnrpc/routerrpc"
+	"github.com/rkfg/regolancer/helpmessage"
 )
 
 type configParams struct {
@@ -465,16 +466,16 @@ func main() {
 
 	// Print own Help message instead of using the builtin Help function of goflags to group output
 	if params.Help {
-		var opt Options
+		var opt helpmessage.Options
 		if reflect.ValueOf(params).Kind() == reflect.Struct {
 			v := reflect.ValueOf(params)
-			err := scanStruct(v, &opt)
+			err := helpmessage.ScanStruct(v, &opt)
 			if err != nil {
 				fmt.Println(err)
 				os.Exit(1)
 			}
 			var b bytes.Buffer
-			WriteHelp(&opt, parser, &b)
+			helpmessage.WriteHelp(&opt, parser, &b)
 		}
 		os.Exit(1)
 	}