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_cat.go

@@ -34,6 +34,10 @@ func (c *commandFsCat) HasTag(CommandTag) bool {
 
 func (c *commandFsCat) 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

weed/shell/command_fs_cd.go

@@ -34,6 +34,10 @@ func (c *commandFsCd) HasTag(CommandTag) bool {
 
 func (c *commandFsCd) 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

weed/shell/command_fs_du.go

@@ -36,6 +36,10 @@ func (c *commandFsDu) HasTag(CommandTag) bool {
 
 func (c *commandFsDu) 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

weed/shell/command_fs_ls.go

@@ -40,6 +40,10 @@ func (c *commandFsLs) HasTag(CommandTag) bool {
 
 func (c *commandFsLs) Do(args []string, commandEnv *CommandEnv, writer io.Writer) (err error) {
 
+	if handleHelpRequest(c, args, writer) {
+		return nil
+	}
+
 	var isLongFormat, showHidden bool
 	for _, arg := range args {
 		if !strings.HasPrefix(arg, "-") {

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

weed/shell/command_fs_meta_notify.go

@@ -36,6 +36,10 @@ func (c *commandFsMetaNotify) HasTag(CommandTag) bool {
 
 func (c *commandFsMetaNotify) 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

weed/shell/command_fs_mkdir.go

@@ -2,11 +2,12 @@ package shell
 
 import (
 	"context"
-	"github.com/seaweedfs/seaweedfs/weed/pb/filer_pb"
-	"github.com/seaweedfs/seaweedfs/weed/util"
 	"io"
 	"os"
 	"time"
+
+	"github.com/seaweedfs/seaweedfs/weed/pb/filer_pb"
+	"github.com/seaweedfs/seaweedfs/weed/util"
 )
 
 func init() {
@@ -33,6 +34,10 @@ func (c *commandFsMkdir) HasTag(CommandTag) bool {
 
 func (c *commandFsMkdir) 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

weed/shell/command_fs_mv.go

@@ -40,6 +40,10 @@ func (c *commandFsMv) HasTag(CommandTag) bool {
 
 func (c *commandFsMv) Do(args []string, commandEnv *CommandEnv, writer io.Writer) (err error) {
 
+	if handleHelpRequest(c, args, writer) {
+		return nil
+	}
+
 	if len(args) != 2 {
 		return fmt.Errorf("need to have 2 arguments")
 	}

weed/shell/command_fs_pwd.go

@@ -26,6 +26,10 @@ func (c *commandFsPwd) HasTag(CommandTag) bool {
 
 func (c *commandFsPwd) Do(args []string, commandEnv *CommandEnv, writer io.Writer) (err error) {
 
+	if handleHelpRequest(c, args, writer) {
+		return nil
+	}
+
 	fmt.Fprintf(writer, "%s\n", commandEnv.option.Directory)
 
 	return nil

weed/shell/command_fs_rm.go

@@ -39,6 +39,11 @@ func (c *commandFsRm) HasTag(CommandTag) bool {
 }
 
 func (c *commandFsRm) Do(args []string, commandEnv *CommandEnv, writer io.Writer) (err error) {
+
+	if handleHelpRequest(c, args, writer) {
+		return nil
+	}
+
 	isRecursive := false
 	ignoreRecursiveError := false
 	var entries []string

weed/shell/command_fs_tree.go

@@ -35,6 +35,10 @@ func (c *commandFsTree) HasTag(CommandTag) bool {
 
 func (c *commandFsTree) 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

weed/shell/commands.go

@@ -3,13 +3,15 @@ package shell
 import (
 	"context"
 	"fmt"
-	"github.com/seaweedfs/seaweedfs/weed/operation"
+	"io"
-	"github.com/seaweedfs/seaweedfs/weed/pb/volume_server_pb"
-	"github.com/seaweedfs/seaweedfs/weed/storage/needle_map"
 	"net/url"
 	"strconv"
 	"strings"
 
+	"github.com/seaweedfs/seaweedfs/weed/operation"
+	"github.com/seaweedfs/seaweedfs/weed/pb/volume_server_pb"
+	"github.com/seaweedfs/seaweedfs/weed/storage/needle_map"
+
 	"google.golang.org/grpc"
 
 	"github.com/seaweedfs/seaweedfs/weed/pb"
@@ -147,6 +149,37 @@ func findInputDirectory(args []string) (input string) {
 	return input
 }
 
+// isHelpRequest checks if the args contain a help flag (-h, --help, or -help)
+// It also handles combined short flags like -lh or -hl
+func isHelpRequest(args []string) bool {
+	for _, arg := range args {
+		// Check for exact matches
+		if arg == "-h" || arg == "--help" || arg == "-help" {
+			return true
+		}
+		// Check for combined short flags (e.g., -lh, -hl, -rfh)
+		// Limit to reasonable length (2-4 chars total) to avoid matching long options like -verbose
+		if strings.HasPrefix(arg, "-") && !strings.HasPrefix(arg, "--") && len(arg) > 1 && len(arg) <= 4 {
+			for _, char := range arg[1:] {
+				if char == 'h' {
+					return true
+				}
+			}
+		}
+	}
+	return false
+}
+
+// handleHelpRequest checks for help flags and prints the help message if requested.
+// It returns true if the help message was printed, indicating the command should exit.
+func handleHelpRequest(c command, args []string, writer io.Writer) bool {
+	if isHelpRequest(args) {
+		fmt.Fprintln(writer, c.Help())
+		return true
+	}
+	return false
+}
+
 func readNeedleMeta(grpcDialOption grpc.DialOption, volumeServer pb.ServerAddress, volumeId uint32, needleValue needle_map.NeedleValue) (resp *volume_server_pb.ReadNeedleMetaResponse, err error) {
 	err = operation.WithVolumeServerClient(false, volumeServer, grpcDialOption,
 		func(client volume_server_pb.VolumeServerClient) error {