chore: Improve the flag parsing

Change-Id: Id2e25bb22b1ba1544f4da72d6397abc81e3b2442

config.go

@@ -17,8 +17,10 @@ package faygo
 import (
 	"flag"
 	"fmt"
+	"io/ioutil"
 	"math"
 	"os"
+	"path/filepath"
 	"sort"
 	"strconv"
 	"strings"
@@ -191,11 +193,25 @@ func ConfigDir() string {
 	return configDir
 }
 
+func resetFlag() {
+	flag.CommandLine.Init(os.Args[0], flag.ContinueOnError)
+	flag.CommandLine.SetOutput(nil)
+	for _, arg := range os.Args[1:] {
+		if arg == "-help" || arg == "--help" || arg == "-h" || arg == "--h" {
+			fmt.Fprintf(flag.CommandLine.Output(), "Usage:\n")
+			flag.PrintDefaults()
+			os.Exit(2)
+		}
+	}
+}
+
 // global config
 var globalConfig = func() GlobalConfig {
 	// get config dir
-	flag.StringVar(&configDir, "cfg_dir", configDir, "Configuration files directory")
-	flag.Parse()
+	flag.CommandLine.Init(os.Args[0], -1) // ignore error
+	flag.CommandLine.SetOutput(ioutil.Discard)
+	flag.CommandLine.StringVar(&configDir, "cfg_dir", configDir, "Configuration files directory")
+	flag.CommandLine.Parse(os.Args[1:])
 
 	var background = &GlobalConfig{
 		Cache: CacheConfig{
@@ -216,8 +232,7 @@ var globalConfig = func() GlobalConfig {
 			FileLevel:     "debug",
 		},
 	}
-	filename := configDir + globalConfigFile
-
+	filename := filepath.Join(configDir, globalConfigFile)
 	err := SyncINI(
 		background,
 		func(onceUpdateFunc func() error) error {

faygo.go

@@ -80,6 +80,7 @@ func GetFrame(name string, version ...string) (*Framework, bool) {
 
 // Run starts all web services.
 func Run() {
+	global.beforeRun()
 	global.framesLock.Lock()
 	for _, frame := range global.frames {
 		if !frame.Running() {
@@ -88,9 +89,6 @@ func Run() {
 		}
 	}
 	global.framesLock.Unlock()
-	global.graceOnce.Do(func() {
-		graceSignal()
-	})
 	select {}
 }
 
@@ -456,7 +454,7 @@ type (
 		// executed after services are closed, but not guaranteed to be completed.
 		postCloseFunc func() error
 
-		graceOnce sync.Once
+		beforeRunOnce sync.Once
 	}
 	// PresetStatic is the system default static file routing information
 	PresetStatic struct {
@@ -569,3 +567,11 @@ func addFrame(frame *Framework) {
 	}
 	global.frames = append(global.frames, frame)
 }
+
+func (g *GlobalVariables) beforeRun() {
+	g.beforeRunOnce.Do(func() {
+		resetFlag()
+		WritePid(LogDir() + "app.pid")
+		go graceSignal()
+	})
+}

framework.go

@@ -179,10 +179,8 @@ func (frame *Framework) Run() {
 	if frame.Running() {
 		return
 	}
+	global.beforeRun()
 	go frame.run()
-	global.graceOnce.Do(func() {
-		graceSignal()
-	})
 	select {}
 }
 

graceful_a.go

@@ -23,7 +23,6 @@ import (
 )
 
 func graceSignal() {
-	WritePid(LogDir() + "app.pid")
 	// subscribe to SIGINT signals
 	ch := make(chan os.Signal)
 	signal.Notify(ch, os.Interrupt, os.Kill)

graceful_b.go

@@ -25,7 +25,6 @@ import (
 )
 
 func graceSignal() {
-	WritePid(LogDir() + "app.pid")
 	// subscribe to SIGINT signals
 	ch := make(chan os.Signal)
 	signal.Notify(ch, syscall.SIGINT, syscall.SIGTERM, syscall.SIGUSR2)