Added the requirements for the "sort" package to work on a snapshotList

main.go

@@ -6,6 +6,7 @@ import (
 	"fmt"
 	"os/exec"
 	"regexp"
+	"sort"
 	"strings"
 )
 
@@ -29,31 +30,35 @@ func main() {
 	for snapScanner.Scan() {
 		if snapshotLineRegex.MatchString(snapScanner.Text()) {
 			var temp = strings.SplitN(snapScanner.Text(), "\t", 2)
-			var snapshot = ParseSnapshot(temp[0])
-			if snapshot != nil {
-
-				/* var sender = exec.Command("zfs", "send", "-c",
-					snapshot.String())
-				var inData, err = sender.StdoutPipe()
-				if err != nil {
-					break
-				}
-				var receiver = exec.Command("zfs", "receive", "-x",
-					"mountpoint", "backups/test/"+snapshot.Path())
-				var outData io.WriteCloser
-				outData, err = receiver.StdinPipe()
-				if err != nil {
-					break
-				}
-				fmt.Println("Writing ", snapshot.String(), " to backups/test")
-				buf := make([]byte, 4*1024*1024)
-				sender.Start()
-				receiver.Start()
-				io.CopyBuffer(outData, inData, buf)
-				sender.Wait()
-				receiver.Wait()
-				break */
+			var snapshot, err = ParseSnapshot(temp[0])
+			if err != nil {
+				// Ignore the bad input
+			}
+			snapshots[snapshot.Path()].addSnapshot(snapshot)
+			/* var sender = exec.Command("zfs", "send", "-c",
+				snapshot.String())
+			var inData, err = sender.StdoutPipe()
+			if err != nil {
+				break
 			}
+			var receiver = exec.Command("zfs", "receive", "-x",
+				"mountpoint", "backups/test/"+snapshot.Path())
+			var outData io.WriteCloser
+			outData, err = receiver.StdinPipe()
+			if err != nil {
+				break
+			}
+			fmt.Println("Writing ", snapshot.String(), " to backups/test")
+			buf := make([]byte, 4*1024*1024)
+			sender.Start()
+			receiver.Start()
+			io.CopyBuffer(outData, inData, buf)
+			sender.Wait()
+			receiver.Wait()
+			break */
 		}
 	}
+	for i := range snapshots {
+		sort.Sort(snapshots[i])
+	}
 }

snapshot.go

@@ -28,13 +28,11 @@ ParseSnapshot parses a string into a Snapshot.
 
 It returns nil on error.
 */
-func ParseSnapshot(input string) *Snapshot {
-	var snapshotOnly, err = regexp.Compile("^" + PoolNameRegex + "@" + ZfsSnapshotNameRegex + "$")
-	if err != nil {
-		return nil
-	}
+func ParseSnapshot(input string) (result Snapshot, err error) {
+	var snapshotOnly = regexp.MustCompile("^" + PoolNameRegex + "@" + ZfsSnapshotNameRegex + "$")
 	if !snapshotOnly.MatchString(input) {
-		return nil
+		err = errors.New("Input is not a snapshot")
+		return
 	}
 	var snapshotPieces []string = snapshotOnly.FindStringSubmatch(input)
 	var theSnapshot = Snapshot{}
@@ -42,28 +40,28 @@ func ParseSnapshot(input string) *Snapshot {
 	var year, month, day, hour, minute int
 	year, err = strconv.Atoi(snapshotPieces[2])
 	if err != nil {
-		return nil
+		return
 	}
 	month, err = strconv.Atoi(snapshotPieces[3])
 	if err != nil {
-		return nil
+		return
 	}
 	day, err = strconv.Atoi(snapshotPieces[4])
 	if err != nil {
-		return nil
+		return
 	}
 	hour, err = strconv.Atoi(snapshotPieces[5])
 	if err != nil {
-		return nil
+		return
 	}
 	minute, err = strconv.Atoi(snapshotPieces[6])
 	if err != nil {
-		return nil
+		return
 	}
 	theSnapshot.TimeStamp = time.Date(year, time.Month(month), day, hour, minute, 0, 0, time.UTC)
 	var splitInput []string = strings.Split(input, "@")
 	if len(splitInput) != 2 {
-		return nil
+		return
 	}
 	var paths []string = strings.Split(splitInput[0], "/")
 	theSnapshot.pool = paths[0]
@@ -71,7 +69,7 @@ func ParseSnapshot(input string) *Snapshot {
 		theSnapshot.fsTree = make([]string, len(paths)-1)
 		copy(theSnapshot.fsTree, paths[1:])
 	}
-	return &theSnapshot
+	return theSnapshot, nil
 }
 
 func intervalStringToUInt(input string) uint64 {

snapshotlist.go

@@ -3,3 +3,34 @@ package main
 type snapshotList struct {
 	Snapshots []Snapshot
 }
+
+func (snapList snapshotList) addSnapshot(snap Snapshot) {
+	if len(snapList.Snapshots) == 0 {
+		snapList.Snapshots = append(snapList.Snapshots, snap)
+	}
+	snapList.Snapshots = append(snapList.Snapshots, snap)
+}
+
+/*
+Len is required for the sort interface.
+*/
+func (snapList snapshotList) Len() int {
+	return len(snapList.Snapshots)
+}
+
+/*
+Less is required for the sort interface.
+*/
+func (snapList snapshotList) Less(i, j int) bool {
+	return snapList.Snapshots[i].TimeStamp.Before(
+		snapList.Snapshots[j].TimeStamp)
+}
+
+/*
+Swap is required for the sort interface.
+*/
+func (snapList snapshotList) Swap(i, j int) {
+	t := snapList.Snapshots[i]
+	snapList.Snapshots[i] = snapList.Snapshots[j]
+	snapList.Snapshots[j] = t
+}