refactor: using xconf.Usage as default error output

tests/replit/main.go

@@ -2,13 +2,11 @@ package main
 
 import (
 	"bytes"
-	"flag"
 	"fmt"
 	"os"
 
 	"github.com/sandwich-go/xconf"
 	"github.com/sandwich-go/xconf/tests/replit/config"
-	"github.com/sandwich-go/xconf/xflag"
 )
 
 func panicErr(err error) {
@@ -61,7 +59,5 @@ func main() {
 	fmt.Println("empty config etcd : ", empteOne.GetETCD())  // {[10.0.0.1 10.0.0.2 10.0.0.3 10.0.0.4]
 	fmt.Println("empty config redis: ", empteOne.GetRedis()) // {[192.168.0.1 192.168.0.2] true {16m40s 16m40s 16m40s}}
 
-	xconf.DumpInfo()
-	xflag.PrintDefaults(flag.CommandLine)
-
+	xconf.Usage()
 }

xconf.go

@@ -195,18 +195,14 @@ func (x *XConf) parse(valPtr interface{}) (err error) {
 			if !got {
 				val, got = parsedOptions["h"]
 			}
-			if got {
-				if strings.EqualFold(xutil.StringTrim(val), "xconf") {
-					// 指定xconf_usage的FlagArgs为空，避免再次触发help逻辑
-					xx := New(WithFlagSet(newFlagSetContinueOnError("xconf_usage")), WithFlagArgs(), WithErrorHandling(ContinueOnError))
-					cc := NewOptions()
-					xutil.PanicErr(xx.Parse(cc))
-					xx.Usage()
-				} else {
-					x.Usage()
-				}
+			if got && strings.EqualFold(xutil.StringTrim(val), "xconf") {
+				// 指定xconf_usage的FlagArgs为空，避免再次触发help逻辑
+				xx := New(WithFlagSet(newFlagSetContinueOnError("xconf_usage")), WithFlagArgs(), WithErrorHandling(ContinueOnError))
+				cc := NewOptions()
+				xutil.PanicErr(xx.Parse(cc))
+				xx.Usage()
 			} else {
-				xflag.PrintDefaults(x.cc.FlagSet, x.optionUsage)
+				x.Usage()
 			}
 		}
 	}