Create and delete snapshot OK + version bump to 0.25

cmd/list.go

@@ -14,6 +14,7 @@ import (
 
 /********************************************************************************
  * List all properties a jail have, with their internal name
+ * Only print properties name. To get name & values, use GetJailProperties()
  *******************************************************************************/
 func ListJailsProps(args []string) {
 	var conf Jail
@@ -98,7 +99,7 @@ func ListJails(args []string, display bool) {
 	/     We support 3 sort criteria max
 	/**************************************************************/
 	if len(gSortFields) > 0 && gSortFields != "none" {
-		js := initSortStruct()
+		js := initJailSortStruct()
 
 		// The way we manage criteria quantity is not very elegant...
 		var fct1, fct2, fct3 *reflect.Value
@@ -126,11 +127,11 @@ func ListJails(args []string, display bool) {
 
 		switch len(strings.Split(gSortFields, ",")) {
 			case 1:
-				OrderedBy(fct1.Interface().(lessFunc)).Sort(jails)
+				JailsOrderedBy(fct1.Interface().(jailLessFunc)).Sort(jails)
 			case 2:
-				OrderedBy(fct1.Interface().(lessFunc), fct2.Interface().(lessFunc)).Sort(jails)
+				JailsOrderedBy(fct1.Interface().(jailLessFunc), fct2.Interface().(jailLessFunc)).Sort(jails)
 			case 3:
-				OrderedBy(fct1.Interface().(lessFunc), fct2.Interface().(lessFunc), fct3.Interface().(lessFunc)).Sort(jails)
+				JailsOrderedBy(fct1.Interface().(jailLessFunc), fct2.Interface().(jailLessFunc), fct3.Interface().(jailLessFunc)).Sort(jails)
 		}
 	}
 
@@ -138,7 +139,7 @@ func ListJails(args []string, display bool) {
 	/   Finally, display jails
 	/**************************************************************/
 	if display {
-		displayStructFields(jails, fields)
+		displayJailsFields(jails, fields)
 	}
 }
 

cmd/properties.go

@@ -0,0 +1,156 @@
+package cmd
+
+import (
+	"fmt"
+	"errors"
+	"reflect"
+	"strings"
+	"strconv"
+)
+
+func GetJailProperties(args []string) {
+	var props []string
+	var jail Jail
+	
+	if len(args) > 0 {
+		for i, a := range args {
+			// Last arg is the jail name
+			if i == len(args)-1 {
+				jail.Name = a
+			} else {
+				props = append(props, a)
+			}
+		}
+	} 
+	
+	if len(jail.Name) == 0 || len(args) == 0 {
+		// TODO : Show help
+		fmt.Printf("Error\n")
+		return
+	}
+	
+	if isStringInArray(props, "all") {
+		var result []string
+		result = getStructFieldNames(jail, result, "")
+		props = result
+	}
+	
+	for _, p := range props {
+		v, err := getJailProperty(&jail, p)
+		if err != nil {
+			fmt.Printf("Error: %s\n", err.Error())
+			return
+		} else {
+			fmt.Printf("%s = %s\n", p, v)
+		}
+	}
+}
+
+func getJailProperty(jail *Jail, propName string) (string, error) {
+	for i, j := range gJails {
+		if j.Name == jail.Name {
+			val, _, err := getStructFieldValue(&gJails[i], propName)
+			if err != nil {
+				return "", err
+			}
+			
+			switch val.Kind() {
+				case reflect.String:
+					return val.String(), nil
+				case reflect.Int:
+					return strconv.FormatInt(val.Int(), 10), nil
+				case reflect.Bool:
+					return strconv.FormatBool(val.Bool()), nil
+				default:
+					return "", errors.New(fmt.Sprintf("Error: Unknown type for property %s: %s\n", propName, val.Kind()))
+			}
+		}
+	}
+	
+	return "", errors.New(fmt.Sprintf("Jail not found: %s", jail.Name))
+}
+
+func SetJailProperties(args []string) {
+	type properties struct {
+		name	string
+		value	string
+	}
+	
+	var jail Jail
+	var props []properties
+	
+	if len(args) > 0 {
+		for i, a := range args {
+			// This is the jail name
+			if i == len(args)-1 {
+				jail.Name = a
+			} else {
+				kv := strings.Split(a, "=")
+				if len(kv) != 2 {
+					// TODO : Show help
+					fmt.Printf("Error parsing args: %s\n", a)
+					return
+				} else {
+					p := properties{name: kv[0], value: kv[1]}
+					props = append(props, p)
+				}
+			}
+		}
+	} 
+	
+	if len(jail.Name) == 0 || len(args) == 0 {
+		// TODO : Show help
+		fmt.Printf("Error\n")
+		return
+	}
+	
+	for _, p := range props {
+		err := setJailProperty(&jail, p.name, p.value)
+		if err != nil {
+			fmt.Printf("Error: %s\n", err.Error())
+			return
+		}
+	}
+}
+
+// setJailProperty takes a string as propValue, whatever the real property type is.
+//  It will be converted.
+func setJailProperty(jail *Jail, propName string, propValue string) error {
+	for i, j := range gJails {
+		if j.Name == jail.Name {
+			val, _, err := getStructFieldValue(&gJails[i], propName)
+			//val, _, err := getStructFieldValue(&gJails[i].Config, strings.Split(propName, ".")[1])
+			if err != nil {
+				return err
+			}
+			
+			if val.CanSet() {
+				switch val.Kind() {
+					case reflect.String:
+						val.SetString(propValue)
+					case reflect.Int:
+						ival, err := strconv.ParseInt(propValue, 10, 64)
+						if err != nil {
+							return err
+						}
+						val.SetInt(ival)
+					case reflect.Bool:
+						bval, err := strconv.ParseBool(propValue)
+						if err != nil {
+							return err
+						}
+						val.SetBool(bval)
+					default:
+						return errors.New(fmt.Sprintf("Field is an unkown type: %s: %s", propName, val.Kind().String()))
+				}
+				fmt.Printf("%s: %s set to %s\n", jail.Name, propName, propValue)
+				gJails[i].ConfigUpdated = true
+			} else {
+				return errors.New(fmt.Sprintf("Field is not writable : %s", propName))
+			}
+		}
+	}
+	
+	return nil
+}
+

cmd/root.go

@@ -5,6 +5,7 @@ import (
 	"fmt"
 	"strconv"
 	"strings"
+	"io/ioutil"
 	"encoding/json"
 
 	"github.com/spf13/cobra"
@@ -12,7 +13,7 @@ import (
 )
 
 const (
-	gVersion = "0.023"
+	gVersion = "0.25"
 )
 
 var (
@@ -28,8 +29,10 @@ var (
 
 	gHostVersion	float64
 	
+	gTimeZone		string
+	gSnapshotName	string
 
-	rootCmd = & cobra.Command{
+	rootCmd = & cobra.Command {
 		Use:    "gocage",
 		Short:  "GoCage is a FreeBSD Jail management tool",
 		Long:   `GoCage is a jail management tool. It support VNET, host-only, NAT networks. Provides snapshots and cloning.
@@ -40,7 +43,7 @@ It support iocage jails and can coexist with iocage.`,
 		},
 	}
 	
-	versionCmd = &cobra.Command{
+	versionCmd = &cobra.Command {
 		Use:   "version",
 		Short: "Print the version number of GoCage",
 		Long:  `Let this show you how much fail I had to get this *cough* perfect`,
@@ -50,7 +53,7 @@ It support iocage jails and can coexist with iocage.`,
 	    },
 	}
 
-	listCmd = &cobra.Command{
+	listCmd = &cobra.Command {
 		Use:   "list",
 		Short: "Print jails",
 		Long:  `Display jails, their IP and OS.
@@ -62,7 +65,7 @@ ex: gocage list srv-db srv-web`,
 		},
 	}
 	
-	listPropsCmd = &cobra.Command{
+	listPropsCmd = &cobra.Command {
 		Use:   "properties",
 		Short: "Print jails properties",
 		Long:  "Display jails properties. You can use properties to filter, get or set them.",
@@ -72,41 +75,101 @@ ex: gocage list srv-db srv-web`,
 		},
 	}
 	
-	stopCmd = &cobra.Command{
+	stopCmd = &cobra.Command {
 		Use:   "stop",
 		Short: "stop jail",
 		Long:  "shutdown jail",
 		Run: func(cmd *cobra.Command, args []string) {
-			// Get the inventory
+			// Load inventory
 			ListJails(args, false)
 			StopJail(args)
 			cleanAfterRun()
 		},
 	}
 
-	startCmd = &cobra.Command{
+	startCmd = &cobra.Command {
 		Use:   "start",
 		Short: "start jail",
 		Run: func(cmd *cobra.Command, args []string) {
-			// Get the inventory
+			// Load inventory
 			ListJails(args, false)
 			StartJail(args)
 			cleanAfterRun()
 		},
 	}
 	
-	setCmd = &cobra.Command{
+	setCmd = &cobra.Command {
 		Use:   "set",
 		Short: "Set a jail property",
 		Long:  `Set jail property value. Specify property=value, end command with jail name.
 Multiples properties can be specified, separated with space (Ex: gocage set allow_mlock=1 boot=1 myjail)`,
 		Run: func(cmd *cobra.Command, args []string) {
-			// Get the inventory
+			// Load inventory
 			ListJails(args, false)
 			SetJailProperties(args)
 			cleanAfterRun()
 		},
 	}
+	
+	getCmd = &cobra.Command {
+		Use:   "get",
+		Short: "Get a jail property",
+		Long:  `Get jail property value. Specify property, end command with jail name.
+Multiples properties can be specified, separated with space (Ex: gocage get allow_mlock boot myjail)
+For all properties specify "all" (Ex: gocage get all myjail)`,
+		Run: func(cmd *cobra.Command, args []string) {
+			// Load inventory
+			ListJails(args, false)
+			GetJailProperties(args)
+			cleanAfterRun()
+		},
+	}
+	
+	snapshotCmd = &cobra.Command {
+		Use:   "snapshot",
+		Short: "snapshot jail",
+		Long:  "Commands to manage jail snapshots. If no arguments given, ",
+		Run: func(cmd *cobra.Command, args []string) {
+
+		},
+	}
+	
+	snapshotListCmd = &cobra.Command {
+		Use:   "list",
+		Short: "list snapshots",
+		Long:  `List snapshots of a jail by specifying its name. 
+List all snapshots if no jail name specified.
+You can specify multiple jails.`,
+		Run: func(cmd *cobra.Command, args []string) {
+			// Load inventory
+			ListJails(args, false)
+			ListJailsSnapshots(args)
+		},
+	}
+	 
+	 snapshotCreateCmd = &cobra.Command {
+		 Use:   "create",
+		Short: "create snapshots",
+		Long:  `Create snapshot of a jail by specifying snapshot name and jail name.`,
+//		You can specify multiple jails.`,
+		Run: func(cmd *cobra.Command, args []string) {
+			// Load inventory
+			ListJails(args, false)
+			CreateJailSnapshot(args)
+		},
+	}
+	
+	snapshotDeleteCmd = &cobra.Command {
+		Use:   "destroy",
+		Short: "destroy snapshots",
+		Long:  `Destroy snapshot of a jail by specifying snapshot name and jail name.`,
+		//		You can specify multiple jails.`,
+		Run: func(cmd *cobra.Command, args []string) {
+			// Load inventory
+			ListJails(args, false)
+			DeleteJailSnapshot(args)
+		},
+	}
 )
 
 
@@ -117,20 +180,34 @@ func init() {
 // Global switches
 	rootCmd.PersistentFlags().StringVarP(&gConfigFile, "config", "c", "/usr/local/etc/gocage.conf.yml", "GoCage configuration file")
 	rootCmd.PersistentFlags().BoolVarP(&gUseSudo, "sudo", "u", false, "Use sudo to run commands")
+	rootCmd.PersistentFlags().StringVarP(&gTimeZone, "timezone", "t", "", "Specify timezone. Will get from /var/db/zoneinfo if not set.")
 
 // Command dependant switches
+
+	// These are persistent so we can reuse them in "gocage list snapshot myjail" command (TODO)
 	listCmd.PersistentFlags().StringVarP(&gDisplayColumns, "outcol", "o", "JID,Name,Config.Release,Config.Ip4_addr,Running", "Show these columns in output")
 	listCmd.PersistentFlags().BoolVarP(&gNoLineSep, "nolinesep", "l", false, "Do not display line separator between jails")
 	listCmd.PersistentFlags().StringVarP(&gFilterJails, "filter", "f", "none", "Only display jails with these values. Ex: \"gocage list -f Config.Boot=1\" will only list started on boot jails")
 	listCmd.PersistentFlags().StringVarP(&gSortFields, "sort", "s", "none", "Display jails sorted by field values. Ex: \"gocage list -s +Name,-Config.Priority\" will sort jails by their decreasing name, then increasing start priority. 3 critera max supported.")
 	
+	// This is local flag : Only available to gocage snapshot create command
+	snapshotCreateCmd.Flags().StringVarP(&gSnapshotName, "snapname", "n", "", "Name of the snapshot to create")
+	snapshotCreateCmd.MarkFlagRequired("snapname")
+	snapshotDeleteCmd.Flags().StringVarP(&gSnapshotName, "snapname", "n", "", "Name of the snapshot to destroy")
+	snapshotDeleteCmd.MarkFlagRequired("snapname")
+    
 // Now declare commands
 	rootCmd.AddCommand(versionCmd)
 	rootCmd.AddCommand(listCmd)
 	listCmd.AddCommand(listPropsCmd)
 	rootCmd.AddCommand(stopCmd)
 	rootCmd.AddCommand(startCmd)
+	rootCmd.AddCommand(getCmd)
 	rootCmd.AddCommand(setCmd)
+	rootCmd.AddCommand(snapshotCmd)
+	snapshotCmd.AddCommand(snapshotListCmd)
+	snapshotCmd.AddCommand(snapshotCreateCmd)
+	snapshotCmd.AddCommand(snapshotDeleteCmd)
 	
 	// Get FreeBSD version
 	out, err := executeCommand("freebsd-version")
@@ -165,6 +242,18 @@ func initConfig() {
 	if rootCmd.Flags().Lookup("sudo") != nil && false == rootCmd.Flags().Lookup("sudo").Changed {
 		gUseSudo = viper.GetBool("sudo")
 	}
+	if rootCmd.Flags().Lookup("timezone") != nil && false == rootCmd.Flags().Lookup("timezone").Changed {
+		gTimeZone = viper.GetString("timezone")
+	}
+	// If neither on cmdline nor config file, get from /var/db/zoneinfo
+	if len(gTimeZone) == 0 {
+		tz, err := ioutil.ReadFile("/var/db/zoneinfo")
+		if err != nil {
+			fmt.Println("Error reading /var/db/zoneinfo: %s\n", err.Error())
+			os.Exit(1)
+		}
+		gTimeZone = strings.Trim(string(tz), "\n")
+	}
 	if listCmd.Flags().Lookup("outcol") != nil && false == listCmd.Flags().Lookup("outcol").Changed {
 		gDisplayColumns = viper.GetString("outcol")
 	}
@@ -187,8 +276,6 @@ func initConfig() {
 func cleanAfterRun() {
 	for _, j := range gJails {
 		if j.ConfigUpdated {
-			// TODO : Marshall to disk
-			//fmt.Printf("Config for jail %s will be updated\n", j.Name)
 			marshaled, err := json.MarshalIndent(j.Config, "", "    ")
 			if err != nil {
 				fmt.Printf("ERROR marshaling config: %s\n", err.Error())

cmd/snapshots.go

@@ -0,0 +1,188 @@
+package cmd
+
+import (
+	"fmt"
+	"time"
+	"regexp"
+	"strings"
+)
+
+/********************************************************************************
+ * List all snapshots jails have
+ *******************************************************************************/
+func ListJailsSnapshots(args []string) {
+	var jailNames []string
+	var snapshots []Snapshot
+	
+	if len(args) > 0 {
+		for _, a := range args {
+			jailNames = append(jailNames, a)
+		}
+	} 
+	
+	if len(jailNames) == 0 || len(args) == 0 {
+		for _, j := range gJails {
+			snapshots = append(snapshots, listJailSnapshots(j)...)
+		}
+	} else {
+		for _, cj := range gJails {
+			for _, jn := range jailNames {
+				if strings.EqualFold(cj.Name, jn) {
+					snapshots = append(snapshots, listJailSnapshots(cj)...)
+				}
+			}
+		}
+	}
+	displaySnapshotsFields(snapshots, []string{"Jailname","Name","Creation","Referenced","Used"})
+}
+
+
+/********************************************************************************
+ * List all snapshots a jail have
+ *******************************************************************************/
+func listJailSnapshots(jail Jail) []Snapshot {
+	var snapshots []Snapshot
+	
+	// 1. List all datasets
+	// TODO : Include mounted filesystems?
+	rs := strings.Split(jail.RootPath, "/")
+	rootDataset := fmt.Sprintf("%s%s", jail.Zpool, strings.Join(rs[:len(rs)-1], "/"))
+	cmd := fmt.Sprintf("zfs list -r -H -o name,mountpoint,used,referenced,creation -t snapshot %s", rootDataset)
+	out, err := executeCommand(cmd)
+	if err != nil {
+		fmt.Printf("Error: %s\n", err.Error())
+		return snapshots
+	}
+	
+	dateLayout := "Mon Jan _2 15:04 2006"
+	loc, _ := time.LoadLocation(gTimeZone)
+	
+	for _, line := range strings.Split(out, "\n") {
+		if len(line) > 0 {
+			ls := strings.Split(line, "\t")
+			// Parse creation date so we can use it to sort snapshots
+			creationts, err := time.ParseInLocation(dateLayout, ls[4], loc)
+			if err != nil {
+				fmt.Println("Error while parsing date %s:", ls[4], err)
+				return snapshots
+			}
+			// Get subdir to append to snapshot name
+			subdir := strings.Replace(strings.Split(ls[0], "@")[0], rootDataset, "", 1)
+			
+			snapshots = append(snapshots, Snapshot{Dsname: ls[0],
+				Name: fmt.Sprintf("%s%s", strings.Split(ls[0], "@")[1], subdir),
+				Jailname: jail.Name,
+				Mountpoint: ls[1],
+				Used: ls[2],
+				Referenced: ls[3],
+				Creation: creationts})
+		}
+	}
+	
+	// Sort snapshots by creation date
+	ss := initSnapshotSortStruct()
+	SnapshotsOrderedBy(ss.CreationInc).Sort(snapshots)
+	
+	return snapshots
+}
+
+
+/********************************************************************************
+ * Create snapshot for jail(s)
+ *******************************************************************************/
+func CreateJailSnapshot(args []string) {
+	var jailNames []string
+	
+	if len(args) > 0 {
+		for _, a := range args {
+			jailNames = append(jailNames, a)
+		}
+	} 
+	
+	for _, cj := range gJails {
+		for _, jn := range jailNames {
+			if strings.EqualFold(cj.Name, jn) {
+				createJailSnapshot(cj)
+			}
+		}
+	}
+}
+
+/********************************************************************************
+ * Create snapshot for a jail
+ *******************************************************************************/
+func createJailSnapshot(jail Jail) error {
+	rs := strings.Split(jail.RootPath, "/")
+	rootDataset := fmt.Sprintf("%s%s", jail.Zpool, strings.Join(rs[:len(rs)-1], "/"))
+	cmd := fmt.Sprintf("zfs snapshot -r %s@%s", rootDataset, gSnapshotName)
+
+	_, err := executeCommand(cmd)
+	if err != nil {
+		fmt.Printf("Error creating snapshot %s@%s: %s\n", rootDataset, gSnapshotName, err.Error())
+		return err
+	}
+	fmt.Printf("Snapshot %s@%s created\n", rootDataset, gSnapshotName)
+	
+	return nil
+}
+
+/********************************************************************************
+ * Delete snapshot for jail(s)
+ *******************************************************************************/
+func DeleteJailSnapshot(args []string) {
+	var jailNames []string
+	
+	if len(args) > 0 {
+		for _, a := range args {
+			jailNames = append(jailNames, a)
+		}
+	} 
+	
+	for _, cj := range gJails {
+		for _, jn := range jailNames {
+			if strings.EqualFold(cj.Name, jn) {
+				deleteJailSnapshot(cj)
+			}
+		}
+	}
+}
+
+/********************************************************************************
+ * Delete snapshot for a jail
+ *******************************************************************************/
+func deleteJailSnapshot(jail Jail) error {
+	var snaptodel []string
+	
+	// Get all recursive snapshots
+	rs := strings.Split(jail.RootPath, "/")
+	rootDataset := fmt.Sprintf("%s%s", jail.Zpool, strings.Join(rs[:len(rs)-1], "/"))
+	cmd := fmt.Sprintf("zfs list -r -H -o name -t snapshot %s", rootDataset)
+	out, err := executeCommand(cmd)
+	if err != nil {
+		fmt.Printf("Error: listing snapshots: %s\n", err.Error())
+		return nil
+	}
+	
+	for _, line := range strings.Split(out, "\n") {
+		if len(line) > 0 {
+			ls := strings.Split(line, "@")
+			
+			matched, _ := regexp.Match(fmt.Sprintf("^%s(\\/.*)?$", gSnapshotName), []byte(ls[1]))
+			if matched {
+				snaptodel = append(snaptodel, strings.Join(ls, "@"))
+			}
+		}
+	}
+	
+	for _, s := range snaptodel {
+		cmd := fmt.Sprintf("zfs destroy %s", s)
+		_, err := executeCommand(cmd)
+		if err != nil {
+			fmt.Printf("Error deleting snapshot %s: %s\n", s, err.Error())
+			return nil
+		}
+		fmt.Printf("Snapshot %s deleted\n", s)
+	}
+	
+	return nil
+}

cmd/start.go

@@ -3,109 +3,11 @@ package cmd
 import (
 	"os"
 	"fmt"
-//	"log"
 	"errors"
 	"regexp"
-//	"os/exec"
-//	"reflect"
 	"strings"
-	"strconv"
 )
 
-func SetJailProperties(args []string) {
-	type properties struct {
-		name	string
-		value	string
-	}
-	
-	var jail Jail
-	var props []properties
-	
-	if len(args) > 0 {
-		for i, a := range args {
-			// This is the jail name
-			if i == len(args)-1 {
-				jail.Name = a
-			} else {
-				kv := strings.Split(a, "=")
-				if len(kv) != 2 {
-					// TODO : Show help
-					fmt.Printf("Error parsing args: %s\n", a)
-					return
-				} else {
-					p := properties{name: kv[0], value: kv[1]}
-					props = append(props, p)
-				}
-			}
-		}
-	} 
-	
-	if len(jail.Name) == 0 || len(args) == 0 {
-		// TODO : Show help
-		fmt.Printf("Error\n")
-		return
-	}
-	
-	for _, p := range props {
-		err := setJailProperty(&jail, p.name, p.value)
-		if err != nil {
-			fmt.Printf("Error: %s\n", err.Error())
-			return
-		}
-	}
-}
-
-// TODO : Support types. For now we just update int, other types will crash
-// WIP. Not working now (need to address the real struct field, not a copy of it)
-// setJailProperty takes a string as propValue, whatever the real property type is.
-//  It will be converted.
-func setJailProperty(jail *Jail, propName string, propValue string) error {
-	// First get propName type, to convert propValue
-/*	k, _, err := getStructFieldKind(jail, propName)
-	if err != nil {
-		return err
-	}
-	kind := k.String()
-*/
-
-	for i, j := range gJails {
-		if j.Name == jail.Name {
-			val, _, err := getStructFieldValue(&gJails[i], propName)
-			//val, _, err := getStructFieldValue(&gJails[i].Config, strings.Split(propName, ".")[1])
-			if err != nil {
-				return err
-			}
-
-			/*if kind == "string" {
-			// WIll the affectation be done in source object or a copy?
-				val.Set(propValue)
-			} else if kind == "int" {
-				v, err := strconv.Atoi(propValue)
-				if err != nil {
-					return errors.New(fmt.Sprintf("propValue have wrong type: %s\n", err.Error()))
-				}
-				val.Set(v)
-			} else {
-				return errors.New(fmt.Sprintf("Property %s have an unsupported type in setJailProperty!\n", propName))
-			}*/
-
-			if val.CanSet() {
-				ival, err := strconv.Atoi(propValue)
-				if err != nil {
-					return err
-				}
-				val.SetInt(int64(ival))
-				fmt.Printf("%s: %s set to %s\n", jail.Name, propName, propValue)
-				gJails[i].ConfigUpdated = true
-			} else {
-				return errors.New(fmt.Sprintf("Field is not writable : %s", propName))
-			}
-		}
-	}
-
-	return nil
-}
-
 // FIXME : Do not work?!
 //  We cant use internalName as the value exist only when jail is running
 func setJailConfigUpdated(jail *Jail) error {

cmd/struct.go

@@ -1,5 +1,8 @@
 package cmd
 
+import (
+	"time"
+)
 
 // To allow sorting, just duplicate fields in JailSort below
 type Jail struct {
@@ -174,303 +177,326 @@ type Mount struct {
 	Fs_Passno	int
 }
 
-
-// This struct hold "sort by jail fields" functions
-type lessFunc func(j1 *Jail, j2 *Jail) bool
+type Snapshot struct {
+	// snapshot name is stored after '@' in dataset name
+	Name		string
+	Dsname		string
+	Jailname	string
+	Mountpoint	string
+	Used		string
+	Referenced	string
+	Creation	time.Time
+}
 
 // Fields in this struct are acquired by their name using reflection
 //  So these char are forbidden for field name: -+.
 //
 type JailSort struct {
-    NameInc					lessFunc
-	NameDec					lessFunc
-    InternalNameInc			lessFunc
-    InternalNameDec			lessFunc
-    JIDInc					lessFunc 
-    JIDDec					lessFunc 
-    RootPathInc				lessFunc
-    RootPathDec				lessFunc
-	ConfigPathInc			lessFunc
-	ConfigPathDec			lessFunc
-    RunningInc				lessFunc
-    RunningDec				lessFunc
-    ZpoolInc				lessFunc
-    ZpoolDec				lessFunc
+	NameInc					jailLessFunc
+	NameDec					jailLessFunc
+	InternalNameInc			jailLessFunc
+	InternalNameDec			jailLessFunc
+	JIDInc					jailLessFunc 
+	JIDDec					jailLessFunc 
+	RootPathInc				jailLessFunc
+	RootPathDec				jailLessFunc
+	ConfigPathInc			jailLessFunc
+	ConfigPathDec			jailLessFunc
+	RunningInc				jailLessFunc
+	RunningDec				jailLessFunc
+    ZpoolInc				jailLessFunc
+    ZpoolDec				jailLessFunc
 	Config					JailConfigSort
 }
 
-
 type JailConfigSort struct {
-	Config_versionInc		lessFunc
-	Config_versionDec		lessFunc
-	Allow_chflagsInc		lessFunc
-	Allow_chflagsDec		lessFunc
-	Allow_mlockInc			lessFunc
-	Allow_mlockDec			lessFunc
-	Allow_mountInc			lessFunc
-	Allow_mountDec			lessFunc
-	Allow_mount_devfsInc	lessFunc
-	Allow_mount_devfsDec	lessFunc
-	Allow_mount_fusefsInc	lessFunc
-	Allow_mount_fusefsDec	lessFunc
-	Allow_mount_nullfsInc	lessFunc
-	Allow_mount_nullfsDec	lessFunc
-	Allow_mount_procfsInc	lessFunc
-	Allow_mount_procfsDec	lessFunc
-	Allow_mount_tmpfsInc	lessFunc
-	Allow_mount_tmpfsDec	lessFunc
-	Allow_mount_zfsInc		lessFunc
-	Allow_mount_zfsDec		lessFunc
-	Allow_quotasInc			lessFunc
-	Allow_quotasDec			lessFunc
-	Allow_raw_socketsInc	lessFunc
-	Allow_raw_socketsDec	lessFunc
-	Allow_set_hostnameInc	lessFunc
-	Allow_set_hostnameDec	lessFunc
-	Allow_socket_afInc		lessFunc
-	Allow_socket_afDec		lessFunc
-	Allow_sysvipcInc		lessFunc
-	Allow_sysvipcDec		lessFunc
-	Allow_tunInc			lessFunc
-	Allow_tunDec			lessFunc
-	Allow_vmmInc			lessFunc
-	Allow_vmmDec			lessFunc
-	Assign_localhostInc		lessFunc
-	Assign_localhostDec		lessFunc
-	AvailableInc			lessFunc
-	AvailableDec			lessFunc
-	BasejailInc				lessFunc
-	BasejailDec				lessFunc
-	BootInc					lessFunc
-	BootDec					lessFunc
-	BpfInc					lessFunc
-	BpfDec					lessFunc
-	Children_maxInc			lessFunc
-	Children_maxDec			lessFunc
-	Cloned_releaseInc		lessFunc
-	Cloned_releaseDec		lessFunc
-	CommentInc				lessFunc
-	CommentDec				lessFunc
-	CompressionInc			lessFunc
-	CompressionDec			lessFunc
-	CompressratioInc		lessFunc
-	CompressratioDec		lessFunc
-	CoredumpsizeInc			lessFunc
-	CoredumpsizeDec			lessFunc
-	CountInc				lessFunc
-	CountDec				lessFunc
-	CpusetInc				lessFunc
-	CpusetDec				lessFunc
-	CputimeInc				lessFunc
-	CputimeDec				lessFunc
-	DatasizeInc				lessFunc
-	DatasizeDec				lessFunc
-	DedupInc				lessFunc
-	DedupDec				lessFunc
-	DefaultrouterInc		lessFunc
-	DefaultrouterDec		lessFunc
-	Defaultrouter6Inc		lessFunc
-	Defaultrouter6Dec		lessFunc
-	DependsInc				lessFunc
-	DependsDec				lessFunc
-	Devfs_rulesetInc		lessFunc
-	Devfs_rulesetDec		lessFunc
-	DhcpInc					lessFunc
-	DhcpDec					lessFunc
-	Enforce_statfsInc		lessFunc
-	Enforce_statfsDec		lessFunc
-	Exec_cleanInc			lessFunc
-	Exec_cleanDec			lessFunc
-	Exec_createdInc			lessFunc
-	Exec_createdDec			lessFunc
-	Exec_fibInc				lessFunc
-	Exec_fibDec				lessFunc
-	Exec_jail_userInc		lessFunc
-	Exec_jail_userDec		lessFunc
-	Exec_poststartInc		lessFunc
-	Exec_poststartDec		lessFunc
-	Exec_poststopInc		lessFunc
-	Exec_poststopDec		lessFunc
-	Exec_prestartInc		lessFunc
-	Exec_prestartDec		lessFunc
-	Exec_prestopInc			lessFunc
-	Exec_prestopDec			lessFunc
-	Exec_startInc			lessFunc
-	Exec_startDec			lessFunc
-	Exec_stopInc			lessFunc
-	Exec_stopDec			lessFunc
-	Exec_system_jail_userInc	lessFunc
-	Exec_system_jail_userDec	lessFunc
-	Exec_system_userInc		lessFunc
-	Exec_system_userDec		lessFunc
-	Exec_timeoutInc			lessFunc
-	Exec_timeoutDec			lessFunc
-	Host_domainnameInc		lessFunc
-	Host_domainnameDec		lessFunc
-	Host_hostnameInc		lessFunc
-	Host_hostnameDec		lessFunc
-	Host_hostuuidInc		lessFunc
-	Host_hostuuidDec		lessFunc
-	Host_timeInc			lessFunc
-	Host_timeDec			lessFunc
-	HostidInc				lessFunc
-	HostidDec				lessFunc
-	Hostid_strict_checkInc	lessFunc
-	Hostid_strict_checkDec	lessFunc
-	InterfacesInc			lessFunc
-	InterfacesDec			lessFunc
-	Ip4Inc					lessFunc
-	Ip4Dec					lessFunc
-	Ip4_addrInc				lessFunc
-	Ip4_addrDec				lessFunc
-	Ip4_saddrselInc			lessFunc
-	Ip4_saddrselDec			lessFunc
-	Ip6Inc					lessFunc
-	Ip6Dec					lessFunc
-	Ip6_addrInc				lessFunc
-	Ip6_addrDec				lessFunc
-	Ip6_saddrselInc			lessFunc
-	Ip6_saddrselDec			lessFunc
-	Ip_hostnameInc			lessFunc
-	Ip_hostnameDec			lessFunc
-	Jail_zfsInc				lessFunc
-	Jail_zfsDec				lessFunc
-	Jail_zfs_datasetInc		lessFunc
-	Jail_zfs_datasetDec		lessFunc
-	Jail_zfs_mountpointInc	lessFunc
-	Jail_zfs_mountpointDec	lessFunc
-	Last_startedInc			lessFunc
-	Last_startedDec			lessFunc
-	Localhost_ipInc			lessFunc
-	Localhost_ipDec			lessFunc
-	Login_flagsInc			lessFunc
-	Login_flagsDec			lessFunc
-	Mac_prefixInc			lessFunc
-	Mac_prefixDec			lessFunc
-	MaxprocInc				lessFunc
-	MaxprocDec				lessFunc
-	MemorylockedInc			lessFunc
-	MemorylockedDec			lessFunc
-	MemoryuseInc			lessFunc
-	MemoryuseDec			lessFunc
-	Min_dyn_devfs_rulesetInc	lessFunc
-	Min_dyn_devfs_rulesetDec	lessFunc
-	Mount_devfsInc			lessFunc
-	Mount_devfsDec			lessFunc
-	Mount_fdescfsInc		lessFunc
-	Mount_fdescfsDec		lessFunc
-	Mount_linprocfsInc		lessFunc
-	Mount_linprocfsDec		lessFunc
-	Mount_procfsInc			lessFunc
-	Mount_procfsDec			lessFunc
-	MountpointInc			lessFunc
-	MountpointDec			lessFunc
-	MsgqqueuedInc			lessFunc
-	MsgqqueuedDec			lessFunc
-	MsgqsizeInc				lessFunc
-	MsgqsizeDec				lessFunc
-	NatInc					lessFunc
-	NatDec					lessFunc
-	Nat_backendInc			lessFunc
-	Nat_backendDec			lessFunc
-	Nat_forwardsInc			lessFunc
-	Nat_forwardsDec			lessFunc
-	Nat_interfaceInc		lessFunc
-	Nat_interfaceDec		lessFunc
-	Nat_prefixInc			lessFunc
-	Nat_prefixDec			lessFunc
-	NmsgqInc				lessFunc
-	NmsgqDec				lessFunc
-	NotesInc				lessFunc
-	NotesDec				lessFunc
-	NsemInc					lessFunc
-	NsemDec					lessFunc
-	NsemopInc				lessFunc
-	NsemopDec				lessFunc
-	NshmInc					lessFunc
-	NshmDec					lessFunc
-	NthrInc					lessFunc
-	NthrDec					lessFunc
-	OpenfilesInc			lessFunc
-	OpenfilesDec			lessFunc
-	OriginInc				lessFunc
-	OriginDec				lessFunc
-	OwnerInc				lessFunc
-	OwnerDec				lessFunc
-	PcpuInc					lessFunc
-	PcpuDec					lessFunc
-	Plugin_nameInc			lessFunc
-	Plugin_nameDec			lessFunc
-	Plugin_repositoryInc	lessFunc
-	Plugin_repositoryDec	lessFunc
-	PriorityInc				lessFunc
-	PriorityDec				lessFunc
-	PseudoterminalsInc		lessFunc
-	PseudoterminalsDec		lessFunc
-	QuotaInc				lessFunc
-	QuotaDec				lessFunc
-	ReadbpsInc				lessFunc
-	ReadbpsDec				lessFunc
-	ReadiopsInc				lessFunc
-	ReadiopsDec				lessFunc
-	ReleaseInc				lessFunc
-	ReleaseDec				lessFunc
-	ReservationInc			lessFunc
-	ReservationDec			lessFunc
-	ResolverInc				lessFunc
-	ResolverDec				lessFunc
-	RlimitsInc				lessFunc
-	RlimitsDec				lessFunc
-	RtsoldInc				lessFunc
-	RtsoldDec				lessFunc
-	SecurelevelInc			lessFunc	
-	SecurelevelDec			lessFunc	
-	ShmsizeInc				lessFunc	
-	ShmsizeDec				lessFunc	
-	StacksizeInc			lessFunc
-	StacksizeDec			lessFunc
-	Stop_timeoutInc			lessFunc
-	Stop_timeoutDec			lessFunc
-	SwapuseInc				lessFunc
-	SwapuseDec				lessFunc
-	Sync_stateInc			lessFunc
-	Sync_stateDec			lessFunc
-	Sync_targetInc			lessFunc
-	Sync_targetDec			lessFunc
-	Sync_tgt_zpoolInc		lessFunc
-	Sync_tgt_zpoolDec		lessFunc
-	SysvmsgInc				lessFunc
-	SysvmsgDec				lessFunc
-	SysvsemInc				lessFunc	
-	SysvsemDec				lessFunc	
-	SysvshmInc				lessFunc	
-	SysvshmDec				lessFunc	
-	TemplateInc				lessFunc
-	TemplateDec				lessFunc
-	JailtypeInc				lessFunc
-	JailtypeDec				lessFunc
-	UsedInc					lessFunc
-	UsedDec					lessFunc
-	VmemoryuseInc			lessFunc
-	VmemoryuseDec			lessFunc
-	VnetInc					lessFunc
-	VnetDec					lessFunc
-	Vnet0_macInc			lessFunc
-	Vnet0_macDec			lessFunc
-	Vnet1_macInc			lessFunc
-	Vnet1_macDec			lessFunc
-	Vnet2_macInc			lessFunc
-	Vnet2_macDec			lessFunc
-	Vnet3_macInc			lessFunc
-	Vnet3_macDec			lessFunc
-	Vnet_default_interfaceInc	lessFunc
-	Vnet_default_interfaceDec	lessFunc
-	Vnet_interfacesInc		lessFunc
-	Vnet_interfacesDec		lessFunc
-	WallclockInc			lessFunc
-	WallclockDec			lessFunc
-	WritebpsInc				lessFunc
-	WritebpsDec				lessFunc
-	WriteiopsInc			lessFunc
-	WriteiopsDec			lessFunc
+	Config_versionInc		jailLessFunc
+	Config_versionDec		jailLessFunc
+	Allow_chflagsInc		jailLessFunc
+	Allow_chflagsDec		jailLessFunc
+	Allow_mlockInc			jailLessFunc
+	Allow_mlockDec			jailLessFunc
+	Allow_mountInc			jailLessFunc
+	Allow_mountDec			jailLessFunc
+	Allow_mount_devfsInc	jailLessFunc
+	Allow_mount_devfsDec	jailLessFunc
+	Allow_mount_fusefsInc	jailLessFunc
+	Allow_mount_fusefsDec	jailLessFunc
+	Allow_mount_nullfsInc	jailLessFunc
+	Allow_mount_nullfsDec	jailLessFunc
+	Allow_mount_procfsInc	jailLessFunc
+	Allow_mount_procfsDec	jailLessFunc
+	Allow_mount_tmpfsInc	jailLessFunc
+	Allow_mount_tmpfsDec	jailLessFunc
+	Allow_mount_zfsInc		jailLessFunc
+	Allow_mount_zfsDec		jailLessFunc
+	Allow_quotasInc			jailLessFunc
+	Allow_quotasDec			jailLessFunc
+	Allow_raw_socketsInc	jailLessFunc
+	Allow_raw_socketsDec	jailLessFunc
+	Allow_set_hostnameInc	jailLessFunc
+	Allow_set_hostnameDec	jailLessFunc
+	Allow_socket_afInc		jailLessFunc
+	Allow_socket_afDec		jailLessFunc
+	Allow_sysvipcInc		jailLessFunc
+	Allow_sysvipcDec		jailLessFunc
+	Allow_tunInc			jailLessFunc
+	Allow_tunDec			jailLessFunc
+	Allow_vmmInc			jailLessFunc
+	Allow_vmmDec			jailLessFunc
+	Assign_localhostInc		jailLessFunc
+	Assign_localhostDec		jailLessFunc
+	AvailableInc			jailLessFunc
+	AvailableDec			jailLessFunc
+	BasejailInc				jailLessFunc
+	BasejailDec				jailLessFunc
+	BootInc					jailLessFunc
+	BootDec					jailLessFunc
+	BpfInc					jailLessFunc
+	BpfDec					jailLessFunc
+	Children_maxInc			jailLessFunc
+	Children_maxDec			jailLessFunc
+	Cloned_releaseInc		jailLessFunc
+	Cloned_releaseDec		jailLessFunc
+	CommentInc				jailLessFunc
+	CommentDec				jailLessFunc
+	CompressionInc			jailLessFunc
+	CompressionDec			jailLessFunc
+	CompressratioInc		jailLessFunc
+	CompressratioDec		jailLessFunc
+	CoredumpsizeInc			jailLessFunc
+	CoredumpsizeDec			jailLessFunc
+	CountInc				jailLessFunc
+	CountDec				jailLessFunc
+	CpusetInc				jailLessFunc
+	CpusetDec				jailLessFunc
+	CputimeInc				jailLessFunc
+	CputimeDec				jailLessFunc
+	DatasizeInc				jailLessFunc
+	DatasizeDec				jailLessFunc
+	DedupInc				jailLessFunc
+	DedupDec				jailLessFunc
+	DefaultrouterInc		jailLessFunc
+	DefaultrouterDec		jailLessFunc
+	Defaultrouter6Inc		jailLessFunc
+	Defaultrouter6Dec		jailLessFunc
+	DependsInc				jailLessFunc
+	DependsDec				jailLessFunc
+	Devfs_rulesetInc		jailLessFunc
+	Devfs_rulesetDec		jailLessFunc
+	DhcpInc					jailLessFunc
+	DhcpDec					jailLessFunc
+	Enforce_statfsInc		jailLessFunc
+	Enforce_statfsDec		jailLessFunc
+	Exec_cleanInc			jailLessFunc
+	Exec_cleanDec			jailLessFunc
+	Exec_createdInc			jailLessFunc
+	Exec_createdDec			jailLessFunc
+	Exec_fibInc				jailLessFunc
+	Exec_fibDec				jailLessFunc
+	Exec_jail_userInc		jailLessFunc
+	Exec_jail_userDec		jailLessFunc
+	Exec_poststartInc		jailLessFunc
+	Exec_poststartDec		jailLessFunc
+	Exec_poststopInc		jailLessFunc
+	Exec_poststopDec		jailLessFunc
+	Exec_prestartInc		jailLessFunc
+	Exec_prestartDec		jailLessFunc
+	Exec_prestopInc			jailLessFunc
+	Exec_prestopDec			jailLessFunc
+	Exec_startInc			jailLessFunc
+	Exec_startDec			jailLessFunc
+	Exec_stopInc			jailLessFunc
+	Exec_stopDec			jailLessFunc
+	Exec_system_jail_userInc	jailLessFunc
+	Exec_system_jail_userDec	jailLessFunc
+	Exec_system_userInc		jailLessFunc
+	Exec_system_userDec		jailLessFunc
+	Exec_timeoutInc			jailLessFunc
+	Exec_timeoutDec			jailLessFunc
+	Host_domainnameInc		jailLessFunc
+	Host_domainnameDec		jailLessFunc
+	Host_hostnameInc		jailLessFunc
+	Host_hostnameDec		jailLessFunc
+	Host_hostuuidInc		jailLessFunc
+	Host_hostuuidDec		jailLessFunc
+	Host_timeInc			jailLessFunc
+	Host_timeDec			jailLessFunc
+	HostidInc				jailLessFunc
+	HostidDec				jailLessFunc
+	Hostid_strict_checkInc	jailLessFunc
+	Hostid_strict_checkDec	jailLessFunc
+	InterfacesInc			jailLessFunc
+	InterfacesDec			jailLessFunc
+	Ip4Inc					jailLessFunc
+	Ip4Dec					jailLessFunc
+	Ip4_addrInc				jailLessFunc
+	Ip4_addrDec				jailLessFunc
+	Ip4_saddrselInc			jailLessFunc
+	Ip4_saddrselDec			jailLessFunc
+	Ip6Inc					jailLessFunc
+	Ip6Dec					jailLessFunc
+	Ip6_addrInc				jailLessFunc
+	Ip6_addrDec				jailLessFunc
+	Ip6_saddrselInc			jailLessFunc
+	Ip6_saddrselDec			jailLessFunc
+	Ip_hostnameInc			jailLessFunc
+	Ip_hostnameDec			jailLessFunc
+	Jail_zfsInc				jailLessFunc
+	Jail_zfsDec				jailLessFunc
+	Jail_zfs_datasetInc		jailLessFunc
+	Jail_zfs_datasetDec		jailLessFunc
+	Jail_zfs_mountpointInc	jailLessFunc
+	Jail_zfs_mountpointDec	jailLessFunc
+	Last_startedInc			jailLessFunc
+	Last_startedDec			jailLessFunc
+	Localhost_ipInc			jailLessFunc
+	Localhost_ipDec			jailLessFunc
+	Login_flagsInc			jailLessFunc
+	Login_flagsDec			jailLessFunc
+	Mac_prefixInc			jailLessFunc
+	Mac_prefixDec			jailLessFunc
+	MaxprocInc				jailLessFunc
+	MaxprocDec				jailLessFunc
+	MemorylockedInc			jailLessFunc
+	MemorylockedDec			jailLessFunc
+	MemoryuseInc			jailLessFunc
+	MemoryuseDec			jailLessFunc
+	Min_dyn_devfs_rulesetInc	jailLessFunc
+	Min_dyn_devfs_rulesetDec	jailLessFunc
+	Mount_devfsInc			jailLessFunc
+	Mount_devfsDec			jailLessFunc
+	Mount_fdescfsInc		jailLessFunc
+	Mount_fdescfsDec		jailLessFunc
+	Mount_linprocfsInc		jailLessFunc
+	Mount_linprocfsDec		jailLessFunc
+	Mount_procfsInc			jailLessFunc
+	Mount_procfsDec			jailLessFunc
+	MountpointInc			jailLessFunc
+	MountpointDec			jailLessFunc
+	MsgqqueuedInc			jailLessFunc
+	MsgqqueuedDec			jailLessFunc
+	MsgqsizeInc				jailLessFunc
+	MsgqsizeDec				jailLessFunc
+	NatInc					jailLessFunc
+	NatDec					jailLessFunc
+	Nat_backendInc			jailLessFunc
+	Nat_backendDec			jailLessFunc
+	Nat_forwardsInc			jailLessFunc
+	Nat_forwardsDec			jailLessFunc
+	Nat_interfaceInc		jailLessFunc
+	Nat_interfaceDec		jailLessFunc
+	Nat_prefixInc			jailLessFunc
+	Nat_prefixDec			jailLessFunc
+	NmsgqInc				jailLessFunc
+	NmsgqDec				jailLessFunc
+	NotesInc				jailLessFunc
+	NotesDec				jailLessFunc
+	NsemInc					jailLessFunc
+	NsemDec					jailLessFunc
+	NsemopInc				jailLessFunc
+	NsemopDec				jailLessFunc
+	NshmInc					jailLessFunc
+	NshmDec					jailLessFunc
+	NthrInc					jailLessFunc
+	NthrDec					jailLessFunc
+	OpenfilesInc			jailLessFunc
+	OpenfilesDec			jailLessFunc
+	OriginInc				jailLessFunc
+	OriginDec				jailLessFunc
+	OwnerInc				jailLessFunc
+	OwnerDec				jailLessFunc
+	PcpuInc					jailLessFunc
+	PcpuDec					jailLessFunc
+	Plugin_nameInc			jailLessFunc
+	Plugin_nameDec			jailLessFunc
+	Plugin_repositoryInc	jailLessFunc
+	Plugin_repositoryDec	jailLessFunc
+	PriorityInc				jailLessFunc
+	PriorityDec				jailLessFunc
+	PseudoterminalsInc		jailLessFunc
+	PseudoterminalsDec		jailLessFunc
+	QuotaInc				jailLessFunc
+	QuotaDec				jailLessFunc
+	ReadbpsInc				jailLessFunc
+	ReadbpsDec				jailLessFunc
+	ReadiopsInc				jailLessFunc
+	ReadiopsDec				jailLessFunc
+	ReleaseInc				jailLessFunc
+	ReleaseDec				jailLessFunc
+	ReservationInc			jailLessFunc
+	ReservationDec			jailLessFunc
+	ResolverInc				jailLessFunc
+	ResolverDec				jailLessFunc
+	RlimitsInc				jailLessFunc
+	RlimitsDec				jailLessFunc
+	RtsoldInc				jailLessFunc
+	RtsoldDec				jailLessFunc
+	SecurelevelInc			jailLessFunc	
+	SecurelevelDec			jailLessFunc	
+	ShmsizeInc				jailLessFunc	
+	ShmsizeDec				jailLessFunc	
+	StacksizeInc			jailLessFunc
+	StacksizeDec			jailLessFunc
+	Stop_timeoutInc			jailLessFunc
+	Stop_timeoutDec			jailLessFunc
+	SwapuseInc				jailLessFunc
+	SwapuseDec				jailLessFunc
+	Sync_stateInc			jailLessFunc
+	Sync_stateDec			jailLessFunc
+	Sync_targetInc			jailLessFunc
+	Sync_targetDec			jailLessFunc
+	Sync_tgt_zpoolInc		jailLessFunc
+	Sync_tgt_zpoolDec		jailLessFunc
+	SysvmsgInc				jailLessFunc
+	SysvmsgDec				jailLessFunc
+	SysvsemInc				jailLessFunc	
+	SysvsemDec				jailLessFunc	
+	SysvshmInc				jailLessFunc	
+	SysvshmDec				jailLessFunc	
+	TemplateInc				jailLessFunc
+	TemplateDec				jailLessFunc
+	JailtypeInc				jailLessFunc
+	JailtypeDec				jailLessFunc
+	UsedInc					jailLessFunc
+	UsedDec					jailLessFunc
+	VmemoryuseInc			jailLessFunc
+	VmemoryuseDec			jailLessFunc
+	VnetInc					jailLessFunc
+	VnetDec					jailLessFunc
+	Vnet0_macInc			jailLessFunc
+	Vnet0_macDec			jailLessFunc
+	Vnet1_macInc			jailLessFunc
+	Vnet1_macDec			jailLessFunc
+	Vnet2_macInc			jailLessFunc
+	Vnet2_macDec			jailLessFunc
+	Vnet3_macInc			jailLessFunc
+	Vnet3_macDec			jailLessFunc
+	Vnet_default_interfaceInc	jailLessFunc
+	Vnet_default_interfaceDec	jailLessFunc
+	Vnet_interfacesInc		jailLessFunc
+	Vnet_interfacesDec		jailLessFunc
+	WallclockInc			jailLessFunc
+	WallclockDec			jailLessFunc
+	WritebpsInc				jailLessFunc
+	WritebpsDec				jailLessFunc
+	WriteiopsInc			jailLessFunc
+	WriteiopsDec			jailLessFunc
+}
+
+type SnapshotSort struct {
+	NameInc					snapshotLessFunc
+	NameDec					snapshotLessFunc
+	DsnameInc				snapshotLessFunc
+	DsnameDec				snapshotLessFunc
+	JailnameInc				snapshotLessFunc
+	JailnameDec				snapshotLessFunc
+	MountpointInc			snapshotLessFunc 
+	MountpointDec			snapshotLessFunc 
+	UsedInc					snapshotLessFunc
+	UsedDec					snapshotLessFunc
+	ReferencedInc			snapshotLessFunc
+	ReferencedDec			snapshotLessFunc
+	CreationInc				snapshotLessFunc
+	CreationDec				snapshotLessFunc
 }

cmd/utils.go

@@ -288,9 +288,9 @@ func getStructField(parentStruct interface{}, fieldName string) (reflect.Value,
 /********************************************************************************
  * Pretty display of jails field
  *   Fields to show are given in a string array parameter
- *   Ex. : displayJails(["Name", "JID", "RootPath"])
+ *   Ex. : displayJailsFields(["Name", "JID", "RootPath"])
 *******************************************************************************/
-func displayStructFields(jails []Jail, valsToDisplay []string) {
+func displayJailsFields(jails []Jail, valsToDisplay []string) {
 	/* A line is defined by :
 	 *		Nr of fields
 	 *		For each field :
@@ -495,6 +495,215 @@ func displayStructFields(jails []Jail, valsToDisplay []string) {
 	fmt.Printf("\n")
 }
 
+/********************************************************************************
+ * Pretty display of snapshots field
+ *   Fields to show are given in a string array parameter
+ *   Ex. : displaySnapshotsFields(["Name", "Dsname", "Used"])
+ *******************************************************************************/
+func displaySnapshotsFields(snaps []Snapshot, valsToDisplay []string) {
+	/* A line is defined by :
+	 *		Nr of fields
+	 *		For each field :
+	 *			Its name
+	 *			Its max length
+	 *			Its value
+	 */
+	type Field struct {
+		Name	string
+		MaxLen	int
+		Value	string
+	}
+	
+	type Line []Field
+	
+	type Output []Line
+	var out Output
+	
+	//fmt.Printf("%d fields in a %d items structure\n", len(valsToDisplay), len(jails))
+	
+	// Browse structure to get max length and values
+	for _, s := range snaps {
+		// Have to use a pointer, else reflect.Value.Elem() will panic : https://pkg.go.dev/reflect#Value.Elem
+		tj := &s
+		
+		line := make([]Field, len(valsToDisplay))
+		for i, f := range valsToDisplay {
+			a, f := getStructField(tj, f)
+			
+			field := Field {
+				Name: f,
+			}
+			if a.FieldByName(f).IsValid() {
+				// For now this just contains this item length, will adjust later
+				//  We need to divide length by number of items in string fields (because we can have more than 1 ip4_addr)
+				if reflect.TypeOf(a.FieldByName(f).Interface()).Kind() == reflect.String {
+					itnr := len(strings.Split(string(a.FieldByName(f).Interface().(string)), ","))
+					field.MaxLen = len(fmt.Sprintf("%v", a.FieldByName(f).Interface())) / itnr
+				} else {
+					field.MaxLen = len(fmt.Sprintf("%v", a.FieldByName(f).Interface()))
+				}
+				field.Value = fmt.Sprintf("%v", a.FieldByName(f).Interface())
+			} else {
+				fmt.Printf("Invalid field name: %s\n", f)
+			}
+			line[i] = field
+			
+		}
+		out = append(out, line)
+	}
+	
+	if len(out) == 0 {
+		fmt.Printf("Nothing to see here!\n")
+		return
+	}
+	
+	// Get real maximum length
+	maxlen := make([]int, len(valsToDisplay))
+	for i := 0; i< len(valsToDisplay); i++ {
+		maxlen[i] = len(valsToDisplay[i])
+	}
+	for _, l := range out {
+		for i, f := range l {
+			if f.MaxLen > maxlen[i] {
+				maxlen[i] = f.MaxLen
+			}
+		}
+	}
+	
+	// Align maxlen to the real maximum length
+	for io, l := range out {
+		for ii, _ := range l {
+			// We need to access slice by index if we want to modify content
+			out[io][ii].MaxLen = maxlen[ii]
+		}
+	}
+	
+	totalLen := 0
+	// For each field, add separator and 2 blank spaces 
+	for _, f := range out[0] {
+		totalLen += f.MaxLen + 3
+	}
+	// Then add starting delimiter 
+	totalLen += 1
+	
+	Debug := false
+	if Debug == true {
+		for _, f := range out[0] {
+			fmt.Printf("%s max length : %d\n", f.Name, f.MaxLen)
+		}
+	}
+	
+	// Lets draw things on the screen!
+	// First, headers: 1st separator line
+	for i, f := range out[0] {
+		if i == 0 {	fmt.Printf("+")	}
+		for i := 0 ; i < f.MaxLen+2 ; i++ {	fmt.Printf("=")	}
+		fmt.Printf("+")
+	}
+	fmt.Printf("\n")
+	
+	
+	//  Column names
+	for i, f := range out[0] {
+		if i == 0 {
+			fmt.Printf("|")
+		}
+		/* Use vlsToDisplay to get real name (with "Config.")
+		 *		fmt.Printf(" %s", f.Name)
+		 *		for i := len(f.Name)+1 ; i < f.MaxLen+1 ; i++ {  */
+		fmt.Printf(" %s", valsToDisplay[i])
+		for i := len(valsToDisplay[i])+1 ; i < f.MaxLen+1 ; i++ {
+			fmt.Printf(" ")
+		}
+		fmt.Printf(" |")
+	}
+	//  Finally separator line
+	fmt.Printf("\n")
+	for i, f := range out[0] {
+		if i == 0 {	fmt.Printf("+")	}
+		for i := 0 ; i < f.MaxLen+2 ; i++ {	fmt.Printf("=")	}
+		fmt.Printf("+")
+	}
+	fmt.Printf("\n")
+	
+	// Then display data
+	//  Loop through lines
+	for _, l := range out {
+		
+		// Loop through fields
+		//  In case we need to add a line for a 2nd IP, or whatever object
+		var supplines = make(map[string]string)
+		for i, f := range l {
+			if i == 0 {
+				fmt.Printf("|")
+			}
+			// Special cases of value displaying
+/*			if f.Name == "JID" && f.Value == "0" {
+				fmt.Printf("  ")
+			} else if f.Name == "Ip4_addr" {
+				ia := strings.Split(f.Value, ",")
+				// If we have more than 1 value we need to finish this line, and store value for writing at the end of line loop
+				for i, inter := range ia {
+					if i > 0 {
+						supplines[f.Name] = inter
+					} else {
+						fmt.Printf(" %s", inter)
+					}
+				}
+				//fmt.Printf(" %s", strings.Split(strings.Split(f.Value, "|")[1], "/")[0])
+			} else {*/
+				fmt.Printf(" %s", f.Value)
+			/*}*/
+			// Complete with spaces to the max length
+			for i := len(f.Value)+1 ; i < f.MaxLen+1 ; i++ {
+				fmt.Printf(" ")
+			}
+			fmt.Printf(" |")
+		}
+		// Draw supplementary lines
+		if len(supplines) > 0 {
+			for i, f := range l {
+				if i == 0 {
+					fmt.Printf("\n|")
+				}
+				// Overwrite value in this scope
+				v, exists := supplines[f.Name]
+				if exists {
+					fmt.Printf(" %s", v)
+				} else {
+					// 1st option : Do not redisplay precedent line values
+					fmt.Printf(" ")
+					// 2nd option : Redisplay precedenet line values
+					//fmt.Printf(" %s", f.Value)
+				}
+				// Complete with spaces to the max length
+				for i := len(v)+1 ; i < f.MaxLen+1 ; i++ {
+					fmt.Printf(" ")
+				}
+				fmt.Printf(" |")
+			}
+		}
+		// Draw line separator between jails
+		if !gNoLineSep {
+			fmt.Printf("\n")
+			for i, f := range out[0] {
+				if i == 0 {	fmt.Printf("+")	}
+				for i := 0 ; i < f.MaxLen+2 ; i++ {	fmt.Printf("-")	}
+				fmt.Printf("+")
+			}
+		}
+		fmt.Printf("\n")
+	}
+	if gNoLineSep {
+		for i, f := range out[0] {
+			if i == 0 {	fmt.Printf("+")	}
+			for i := 0 ; i < f.MaxLen+2 ; i++ {	fmt.Printf("-")	}
+			fmt.Printf("+")
+		}
+	}
+	
+	fmt.Printf("\n")
+}
 
 
 /*****************************************************************************
@@ -503,9 +712,10 @@ func displayStructFields(jails []Jail, valsToDisplay []string) {
 *
 *****************************************************************************/
 
-// already defined in cmd/struct.go
-//type lessFunc func(j1 *Jail, j2 *Jail) bool
-func initSortStruct() JailSort {
+// This struct hold "sort by jail fields" functions
+type jailLessFunc func(j1 *Jail, j2 *Jail) bool
+
+func initJailSortStruct() JailSort {
 	jcs := JailConfigSort{
 		Allow_chflagsInc: func(j1, j2 *Jail) bool {
 			return j1.Config.Allow_chflags < j2.Config.Allow_chflags
@@ -1374,34 +1584,34 @@ func initSortStruct() JailSort {
 	return js
 }
 
-// multiSorter implements the Sort interface, sorting the jails within.
-type multiSorter struct {
+// jailSorter implements the Sort interface, sorting the jails within.
+type jailSorter struct {
 	jails	[]Jail
-	less	[]lessFunc
+	less	[]jailLessFunc
 }
 
-// Sort sorts the argument slice according to the less functions passed to OrderedBy.
-func (ms *multiSorter) Sort(jails []Jail) {
-	ms.jails = jails
-	sort.Sort(ms)
+// Sort sorts the argument slice according to the less functions passed to JailsOrderedBy.
+func (js *jailSorter) Sort(jails []Jail) {
+	js.jails = jails
+	sort.Sort(js)
 }
 
-// OrderedBy returns a Sorter that sorts using the less functions, in order.
+// JailsOrderedBy returns a Sorter that sorts using the less functions, in order.
 // Call its Sort method to sort the data.
-func OrderedBy(less ...lessFunc) *multiSorter {
-	return &multiSorter{
+func JailsOrderedBy(less ...jailLessFunc) *jailSorter {
+	return &jailSorter{
 		less: less,
 	}
 }
 
 // Len is part of sort.Interface.
-func (ms *multiSorter) Len() int {
-	return len(ms.jails)
+func (js *jailSorter) Len() int {
+	return len(js.jails)
 }
 
 // Swap is part of sort.Interface.
-func (ms *multiSorter) Swap(i, j int) {
-	ms.jails[i], ms.jails[j] = ms.jails[j], ms.jails[i]
+func (js *jailSorter) Swap(i, j int) {
+	js.jails[i], js.jails[j] = js.jails[j], js.jails[i]
 }
 
 // Less is part of sort.Interface. It is implemented by looping along the
@@ -1410,12 +1620,12 @@ func (ms *multiSorter) Swap(i, j int) {
 // less functions twice per call. We could change the functions to return
 // -1, 0, 1 and reduce the number of calls for greater efficiency: an
 // exercise for the reader.
-func (ms *multiSorter) Less(i, j int) bool {
-	p, q := &ms.jails[i], &ms.jails[j]
+func (js *jailSorter) Less(i, j int) bool {
+	p, q := &js.jails[i], &js.jails[j]
 	// Try all but the last comparison.
 	var k int
-	for k = 0; k < len(ms.less)-1; k++ {
-		less := ms.less[k]
+	for k = 0; k < len(js.less)-1; k++ {
+		less := js.less[k]
 		switch {
 		case less(p, q):
 			// p < q, so we have a decision.
@@ -1428,7 +1638,136 @@ func (ms *multiSorter) Less(i, j int) bool {
 	}
 	// All comparisons to here said "equal", so just return whatever
 	// the final comparison reports.
-	return ms.less[k](p, q)
+	return js.less[k](p, q)
 }
 
 
+/*****************************************************************************
+ * 
+ * Sorting snapshots
+ *
+ *****************************************************************************/
+
+// This struct hold "sort by jail fields" functions
+type snapshotLessFunc func(s1 *Snapshot, s2 *Snapshot) bool
+
+func initSnapshotSortStruct() SnapshotSort {
+	ss := SnapshotSort{
+		NameInc: func(s1, s2 *Snapshot) bool {
+			return s1.Name < s2.Name
+		},
+		NameDec: func(s1, s2 *Snapshot) bool {
+			return s1.Name > s2.Name
+		},
+		DsnameInc: func(s1, s2 *Snapshot) bool {
+			return s1.Dsname < s2.Dsname
+		},
+		DsnameDec: func(s1, s2 *Snapshot) bool {
+			return s1.Dsname > s2.Dsname
+		},
+		JailnameInc: func(s1, s2 *Snapshot) bool {
+			return s1.Jailname < s2.Jailname
+		},
+		JailnameDec: func(s1, s2 *Snapshot) bool {
+			return s1.Jailname > s2.Jailname
+		},
+		MountpointInc: func(s1, s2 *Snapshot) bool {
+			return s1.Mountpoint < s2.Mountpoint
+		},
+		MountpointDec: func(s1, s2 *Snapshot) bool {
+			return s1.Mountpoint > s2.Mountpoint
+		},
+		UsedInc: func(s1, s2 *Snapshot) bool {
+			return s1.Used < s2.Used
+		},
+		UsedDec: func(s1, s2 *Snapshot) bool {
+			return s1.Used > s2.Used
+		},
+		ReferencedInc: func(s1, s2 *Snapshot) bool {
+			return s1.Referenced < s2.Referenced
+		},
+		ReferencedDec: func(s1, s2 *Snapshot) bool {
+			return s1.Referenced > s2.Referenced
+		},
+		CreationInc: func(s1, s2 *Snapshot) bool {
+			return s1.Creation.Unix() < s2.Creation.Unix()
+		},
+		CreationDec: func(s1, s2 *Snapshot) bool {
+			return s1.Creation.Unix() > s2.Creation.Unix()
+		},
+	}
+	return ss
+}
+
+// snapshotSorter implements the Sort interface, sorting the jails within.
+type snapshotSorter struct {
+	snapshots	[]Snapshot
+	less		[]snapshotLessFunc
+}
+
+// Sort sorts the argument slice according to the less functions passed to OrderedBy.
+func (ss *snapshotSorter) Sort(snapshots []Snapshot) {
+	ss.snapshots = snapshots
+	sort.Sort(ss)
+}
+
+// OrderedBy returns a Sorter that sorts using the less functions, in order.
+// Call its Sort method to sort the data.
+func SnapshotsOrderedBy(less ...snapshotLessFunc) *snapshotSorter {
+	return &snapshotSorter{
+		less: less,
+	}
+}
+
+// Len is part of sort.Interface.
+func (ss *snapshotSorter) Len() int {
+	return len(ss.snapshots)
+}
+
+// Swap is part of sort.Interface.
+func (ss *snapshotSorter) Swap(i, j int) {
+	ss.snapshots[i], ss.snapshots[j] = ss.snapshots[j], ss.snapshots[i]
+}
+
+// Less is part of sort.Interface. It is implemented by looping along the
+// less functions until it finds a comparison that discriminates between
+// the two items (one is less than the other). Note that it can call the
+// less functions twice per call. We could change the functions to return
+// -1, 0, 1 and reduce the number of calls for greater efficiency: an
+// exercise for the reader.
+func (ss *snapshotSorter) Less(i, j int) bool {
+	p, q := &ss.snapshots[i], &ss.snapshots[j]
+	// Try all but the last comparison.
+	var k int
+	for k = 0; k < len(ss.less)-1; k++ {
+		less := ss.less[k]
+		switch {
+			case less(p, q):
+				// p < q, so we have a decision.
+				return true
+			case less(q, p):
+				// p > q, so we have a decision.
+				return false
+		}
+		// p == q; try the next comparison.
+	}
+	// All comparisons to here said "equal", so just return whatever
+	// the final comparison reports.
+	return ss.less[k](p, q)
+}
+
+
+/*****************************************************************************
+ *
+ * Generic utilities
+ *
+ *****************************************************************************/
+func isStringInArray(strarr []string, searched string) bool {
+	for _, s := range strarr {
+		if strings.EqualFold(s, searched) {
+			return true
+		}
+	}
+	return false
+}
+