Basic idea is working. It watches a directory and runs a command when you change things.

go.mod

@@ -1,3 +1,7 @@
 module lcthw.dev/go/ttarpit
 
 go 1.25.3
+
+require github.com/fsnotify/fsnotify v1.9.0
+
+require golang.org/x/sys v0.13.0 // indirect

go.sum

@@ -0,0 +1,4 @@
+github.com/fsnotify/fsnotify v1.9.0 h1:2Ml+OJNzbYCTzsxtv8vKSFD9PbJjmhYF14k/jKC7S9k=
+github.com/fsnotify/fsnotify v1.9.0/go.mod h1:8jBTzvmWwFyi3Pb8djgCCO5IBqzKJ/Jwo8TRcHyHii0=
+golang.org/x/sys v0.13.0 h1:Af8nKPmuFypiUBjVoU9V20FiaFXOcuZI21p0ycVYYGE=
+golang.org/x/sys v0.13.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=

main.go

@@ -6,11 +6,14 @@ import (
   "log"
   "io"
   "os"
+  "io/fs"
+  "path/filepath"
   "errors"
   "lcthw.dev/go/ttarpit/config"
-  "sync"
+  "github.com/fsnotify/fsnotify"
 )
 
+
 func LaunchLogger(in io.Reader, out io.Writer, err error) {
   if err != nil { log.Fatal(err) }
 
@@ -50,11 +53,7 @@ func LaunchProcess(proc *config.Process) {
   }
 }
 
-func main() {
-  config.Load()
-
-  var wg sync.WaitGroup
-
+func RunBuild() {
   fmt.Println("CONFIG:", config.Settings.ConfigPath)
   fmt.Println("COMMANDs:", config.Settings.Processes)
 
@@ -62,11 +61,76 @@ func main() {
     fmt.Println("PROCESS:", name)
 
     proc.Ready = make(chan string)
-    wg.Go(func() {
     LaunchProcess(&proc)
+  }
+}
+
+func AddWatchDir(watcher *fsnotify.Watcher, name string) error {
+  return filepath.WalkDir(name,
+  func(path string, d fs.DirEntry, err error) error {
+    if err != nil {
+      log.Printf("WATCH ERROR! walking=%s path=%s: err=%v", name, path, err)
+      return err
+    }
+
+    if d.IsDir() {
+      log.Println("WATCHING: ", path)
+      err = watcher.Add(path)
+      if err != nil {
+        log.Printf("failed to watch %s", path)
+        return err
+      }
+    }
+
+    return nil
   })
+}
+
+func WatchDir() {
+  watcher, err := fsnotify.NewWatcher()
+  if err != nil {
+    log.Fatal("Failed to start fsnotify", err)
+  }
+  defer watcher.Close()
+
+  go func() {
+    for {
+      select {
+      case event, ok := <-watcher.Events:
+        if !ok {
+          return
+        }
+
+        if event.Has(fsnotify.Create) {
+          log.Println("---> CREATE", event.Name)
+          // ADD DIR
+        } else {
+          log.Println("event:", event)
         }
+        // check if match then do thing
+        go RunBuild()
+      case err, ok := <-watcher.Errors:
+        if !ok {
+          return
+        }
+        log.Println("error: ", err)
+      }
+    }
+  }()
+
+  err = AddWatchDir(watcher, ".")
+
+  if err != nil {
+    log.Fatal(err, "Failed to watch .")
+  }
+
+  <-make(chan struct{})
+}
+
+
+func main() {
+  config.Load()
 
   fmt.Println("WAITING....")
-  wg.Wait()
+  WatchDir()
 }