Decided to implement an inotify watcher for a playlist file. Dunno if it works correctly, but it seems like, not tested yet.

internal/radio/playlist.go

@@ -1,9 +1,12 @@
 package radio
 
 import (
+	"dwelling-radio/pkg/watcher"
+	"log"
 	"os"
 	"strings"
 	"sync"
+	"syscall"
 )
 
 // Playlist holds a list of paths to a song files.
@@ -13,6 +16,8 @@ type Playlist struct {
 	playlist []string
 	cur      int
 	repeat   bool
+	watcher  *watcher.InotifyWatcher
+	changed  chan uint32
 }
 
 // NewPlaylist returns an instance of a Playlist struct with a loaded playlist.
@@ -58,3 +63,34 @@ func (p *Playlist) load() error {
 func (p *Playlist) Reload() error {
 	return p.load()
 }
+
+func (p *Playlist) Watch() (err error) {
+	p.watcher, err = watcher.NewInotifyWatcher()
+	if err != nil {
+		return err
+	}
+
+	err = p.watcher.AddWatch(p.filePath, watcher.ModIgnMask)
+	if err != nil {
+		return err
+	}
+
+	p.watcher.WatchForMask(p.changed, watcher.ModIgnMask)
+
+	go func() {
+		for {
+			mask := <-p.changed
+
+			if mask&syscall.IN_MODIFY > 0 {
+				if err := p.load(); err != nil {
+					log.Fatalln("cannot reload a changed playlist:", err)
+				}
+			} else if mask&syscall.IN_IGNORED > 0 {
+				p.watcher.Close()
+				p.Watch()
+			}
+		}
+	}()
+
+	return nil
+}