Make sure non one-shot executions perform reloads.

Allow for instant ^C without waiting for sleep.

cmd/hostpersister/main.go

@@ -62,6 +62,9 @@ func main() {
 		sigs := make(chan os.Signal, 1)
 		signal.Notify(sigs, syscall.SIGINT, syscall.SIGTERM)
 
+		//Finished notifier:
+		finNotf := make(chan bool, 1)
+
 		z := time.Now().Sub(y)
 		log.Printf("[Main] Took '%s' to fully initialize modules\n", z.String())
 
@@ -69,9 +72,19 @@ func main() {
 		syncDur := time.Duration(syncTime) * time.Millisecond
 
 		go func(exec *bool) {
-			for *exec {
 			executePersistence(hostsFile, sourceFile, overwriteMode)
-				time.Sleep(syncDur)
+			sleep(syncDur, finNotf)
+			for *exec {
+				err := hostsFile.ReadHostsFile()
+				if err != nil {
+					log.Fatalln("Failed to load HOSTS_FILE")
+				}
+				err = sourceFile.ReadHostsFile()
+				if err != nil {
+					log.Fatalln("Failed to load SOURCE_FILE")
+				}
+				executePersistence(hostsFile, sourceFile, overwriteMode)
+				sleep(syncDur, finNotf)
 			}
 		}(&exec)
 
@@ -80,6 +93,7 @@ func main() {
 			fmt.Printf("\n")
 
 			*exec = false
+			finNotf <- true
 
 			a := time.Now()
 			log.Printf("[Main] Signalling program exit...\n")
@@ -107,3 +121,12 @@ func executePersistence(hostsFile *hosts.File, sourceFile *hosts.File, ovrw bool
 		log.Println("[Main] Error Writing Hosts File.")
 	}
 }
+
+func sleep(d time.Duration, n chan bool) {
+	select {
+	case <-n:
+		break
+	case <-time.After(d):
+		break
+	}
+}

hosts/File.go

@@ -9,52 +9,14 @@ import (
 const readBufferSize = 8192
 
 func NewHostsFile(filePath string) (*File, error) {
-	theFile, err := os.Open(filePath)
-	if err != nil {
-		return nil, err
-	}
-	defer theFile.Close()
-	var theEntries []Entry
-	var lenIn int
-	lineEnding := ""
-	theCBuffer := ""
-	theBuffer := make([]byte, readBufferSize)
-	for err == nil {
-		lenIn, err = theFile.Read(theBuffer)
-		if lenIn > 0 {
-			theCBuffer += string(theBuffer[:lenIn])
-			if lineEnding == "" {
-				if strings.Contains(theCBuffer, "\r\n") {
-					lineEnding = "\r\n"
-				} else if strings.Contains(theCBuffer, "\r") {
-					lineEnding = "\r"
-				} else if strings.Contains(theCBuffer, "\n") {
-					lineEnding = "\n"
-				}
-			}
-			if lineEnding == "\r\n" {
-				strings.ReplaceAll(theCBuffer, "\r\n", "\n")
-			} else if lineEnding == "\r" {
-				strings.ReplaceAll(theCBuffer, "\r", "\n")
-			}
-			splt := strings.Split(theCBuffer, "\n")
-			for i := 0; i < len(splt)-1; i++ {
-				theEntries = append(theEntries, NewHostsEntry(splt[i]))
-			}
-			theCBuffer = splt[len(splt)-1]
-		}
-	}
-	if err != io.EOF {
-		return nil, err
-	}
-	if theCBuffer != "" {
-		theEntries = append(theEntries, NewHostsEntry(theCBuffer))
-	}
-	return &File{
+	theHostFile := &File{
 		filePath: filePath,
-		Entries:    theEntries,
-		lineEnding: lineEnding,
-	}, nil
+	}
+	err := theHostFile.ReadHostsFile()
+	if err == nil {
+		return theHostFile, nil
+	}
+	return nil, err
 }
 
 type File struct {
@@ -63,6 +25,51 @@ type File struct {
 	lineEnding string
 }
 
+func (f *File) ReadHostsFile() error {
+	f.Entries = nil
+	theFile, err := os.Open(f.filePath)
+	if err != nil {
+		return err
+	}
+	defer theFile.Close()
+	var lenIn int
+	f.lineEnding = ""
+	theCBuffer := ""
+	theBuffer := make([]byte, readBufferSize)
+	for err == nil {
+		lenIn, err = theFile.Read(theBuffer)
+		if lenIn > 0 {
+			theCBuffer += string(theBuffer[:lenIn])
+			if f.lineEnding == "" {
+				if strings.Contains(theCBuffer, "\r\n") {
+					f.lineEnding = "\r\n"
+				} else if strings.Contains(theCBuffer, "\r") {
+					f.lineEnding = "\r"
+				} else if strings.Contains(theCBuffer, "\n") {
+					f.lineEnding = "\n"
+				}
+			}
+			if f.lineEnding == "\r\n" {
+				strings.ReplaceAll(theCBuffer, "\r\n", "\n")
+			} else if f.lineEnding == "\r" {
+				strings.ReplaceAll(theCBuffer, "\r", "\n")
+			}
+			splt := strings.Split(theCBuffer, "\n")
+			for i := 0; i < len(splt)-1; i++ {
+				f.Entries = append(f.Entries, NewHostsEntry(splt[i]))
+			}
+			theCBuffer = splt[len(splt)-1]
+		}
+	}
+	if err != io.EOF {
+		return err
+	}
+	if theCBuffer != "" {
+		f.Entries = append(f.Entries, NewHostsEntry(theCBuffer))
+	}
+	return nil
+}
+
 func (f File) WriteHostsFile() error {
 	theFile, err := os.OpenFile(f.filePath, os.O_CREATE|os.O_TRUNC|os.O_WRONLY, 0644)
 	if err != nil {