Add filewatcher as a helper

Author: darkgeek

opensuse-riscv64/bin/watcher.go

@@ -0,0 +1,93 @@
+package main
+
+import (
+    "log/syslog"
+    "log"
+    "os"
+    "github.com/fsnotify/fsnotify"
+)
+
+var logger *log.Logger = getSyslog()
+
+type Watcher interface {
+    start(string)
+}
+
+type FsnotifyWatcher struct {
+}
+
+func (f FsnotifyWatcher) start(filePath string) {
+    // Create new watcher.
+    watcher, err := fsnotify.NewWatcher()
+    if err != nil {
+        logger.Fatal(err)
+    }
+    defer watcher.Close()
+
+    // Start listening for events.
+    go func() {
+        for {
+            select {
+            case event, ok := <-watcher.Events:
+                if !ok {
+                    return
+                }
+                logger.Println("[filewatcher] event:", event)
+                if event.Has(fsnotify.Write) {
+                    logger.Println("[filewatcher] modified file:", event.Name)
+                }
+                fileInfo, err := os.Stat(filePath)
+                if (err != nil) {
+                    logger.Println("[filewatcher] Error:", err)
+                }
+                if (fileInfo.Size() != 0) {
+                    logger.Printf("[filewatcher] file %s has content now.\n", filePath)
+                    os.Exit(0)
+                }
+            case err, ok := <-watcher.Errors:
+                if !ok {
+                    return
+                }
+                logger.Println("[filewatcher] error:", err)
+            }
+        }
+    }()
+
+    // Add a path.
+    err = watcher.Add(filePath)
+    if err != nil {
+        logger.Fatal(err)
+    }
+
+    // Block main goroutine forever.
+    <-make(chan struct{})
+}
+
+func getFilePath(args []string) string {
+    if (len(args) < 1) {
+        log.Fatalln("You must specify a file path to watch!")
+        os.Exit(1)
+    }
+
+    return args[0]
+}
+
+func getSyslog() *log.Logger {
+    logger,err := syslog.NewLogger(syslog.LOG_INFO, 0)
+    if err != nil {
+        log.Fatal(err)
+        os.Exit(2)
+    }
+
+    return logger
+}
+
+func start(watcher Watcher, filePath string) {
+    watcher.start(filePath)
+}
+
+func main() {
+    filePath := getFilePath(os.Args[1:])
+    fsWatcher := FsnotifyWatcher {}
+    start(fsWatcher, filePath)
+}