Shell: Added a helper function isHelpRequest() (#7380)

* Added a helper function `isHelpRequest()`

* also handles combined short flags like -lh or -hl

* Created handleHelpRequest() helper function

encapsulates both:
Checking for help flags
Printing the help message

* Limit to reasonable length (2-4 chars total) to avoid matching long options like -verbose

weed/shell/command_fs_meta_cat.go

@@ -3,11 +3,12 @@ package shell
 import (
 	"context"
 	"fmt"
-	"github.com/seaweedfs/seaweedfs/weed/filer"
-	"google.golang.org/protobuf/proto"
 	"io"
 	"sort"
 
+	"github.com/seaweedfs/seaweedfs/weed/filer"
+	"google.golang.org/protobuf/proto"
+
 	"github.com/seaweedfs/seaweedfs/weed/pb/filer_pb"
 	"github.com/seaweedfs/seaweedfs/weed/util"
 )
@@ -37,6 +38,10 @@ func (c *commandFsMetaCat) HasTag(CommandTag) bool {
 
 func (c *commandFsMetaCat) Do(args []string, commandEnv *CommandEnv, writer io.Writer) (err error) {
 
+	if handleHelpRequest(c, args, writer) {
+		return nil
+	}
+
 	path, err := commandEnv.parseUrl(findInputDirectory(args))
 	if err != nil {
 		return err