improve commands (#648)

* stat show json refactor
> will show {} since scripts should expect it, its the json style of blank value

* combine statistics commands to one

* code optimize

* fix runtime flag

* remove json indent

* change overridden to override

* api bi -json

* convert stdin support
code optimize

* writeRow() code optimize
add stats tittle
revert back to restartlogger

* api log -restart

* follow log

* codeql

* move -json to shared flags

* flags optimize
* update flag descriptions
* change "-v" of "api bo" to duration
* change "-expire" of "tls cert" to days

* cmds short description optimize

* fix multiple log followers

* Format loader refactor
* "infra/conf/merge" refactor
* "LoadConfig" refactor
* add "infra/conf/mergers"
    * contribute to it will benifit `v2ray run`,`v2ray test`,`v2ray convert`
    * easily add new formats, by just adding a converter like json.FromTOML
* default format auto, to all cmds above
    * auto detect input format
    * mixed formats support
* better stdin behavior
    * don't wait if no content
    * don't use 'stdin:' placeholder
* `v2ray test` now behaves exactly the same with `v2ray run`, including stdin reading

* api ado, adi, rmo, rmi refactor
* support folders to files resolving, mixed formats
* remove remaining 'stdin:' placeholders

* fix tests
* os.Stdin.Stat() behaves different in platforms, removed

* code optimize

Co-authored-by: loyalsoldier <10487845+Loyalsoldier@users.noreply.github.com>

app/log/command/command.go

@@ -4,14 +4,17 @@ package command
 
 import (
 	"context"
+	"time"
 
 	grpc "google.golang.org/grpc"
 
 	core "github.com/v2fly/v2ray-core/v4"
 	"github.com/v2fly/v2ray-core/v4/app/log"
 	"github.com/v2fly/v2ray-core/v4/common"
+	cmlog "github.com/v2fly/v2ray-core/v4/common/log"
 )
 
+// LoggerServer is the implemention of LoggerService
 type LoggerServer struct {
 	V *core.Instance
 }
@@ -31,6 +34,34 @@ func (s *LoggerServer) RestartLogger(ctx context.Context, request *RestartLogger
 	return &RestartLoggerResponse{}, nil
 }
 
+// FollowLog implements LoggerService.
+func (s *LoggerServer) FollowLog(_ *FollowLogRequest, stream LoggerService_FollowLogServer) error {
+	logger := s.V.GetFeature((*log.Instance)(nil))
+	if logger == nil {
+		return newError("unable to get logger instance")
+	}
+	follower, ok := logger.(cmlog.Follower)
+	if !ok {
+		return newError("logger not support following")
+	}
+	var err error
+	f := func(msg cmlog.Message) {
+		err = stream.Send(&FollowLogResponse{
+			Message: msg.String(),
+		})
+	}
+	follower.AddFollower(f)
+	defer follower.RemoveFollower(f)
+	ticker := time.NewTicker(time.Second)
+	for {
+		<-ticker.C
+		if err != nil {
+			ticker.Stop()
+			return nil
+		}
+	}
+}
+
 func (s *LoggerServer) mustEmbedUnimplementedLoggerServiceServer() {}
 
 type service struct {