added fsnotify example, to check bahavior on windows.

cmd/fsnotifytest/monitor.go

@@ -0,0 +1,58 @@
+package main
+
+import (
+	"fmt"
+	"log"
+
+	"github.com/fsnotify/fsnotify"
+)
+
+// create .hold
+//     CREATE + CHMOD
+// remove
+//     REMOVE
+// touch existing:
+//     CHMOD
+// echo > .hold
+//
+// file name:    ./.hold on linux
+
+func main() {
+	// Create a new watcher
+	watcher, err := fsnotify.NewWatcher()
+	if err != nil {
+		log.Fatal(err)
+	}
+	defer watcher.Close()
+
+	// Start listening for events
+	go func() {
+		for {
+			select {
+			case event, ok := <-watcher.Events:
+				if !ok {
+					return
+				}
+				fmt.Printf("Event: %s File: %s\n", event.Op, event.Name)
+
+				if event.Op&fsnotify.Write == fsnotify.Write {
+					fmt.Println("Modified file:", event.Name)
+				}
+			case err, ok := <-watcher.Errors:
+				if !ok {
+					return
+				}
+				fmt.Println("Error:", err)
+			}
+		}
+	}()
+
+	// Add a directory to watch
+	err = watcher.Add(".")
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	// Block main goroutine forever
+	<-make(chan struct{})
+}

go.mod

@@ -5,6 +5,7 @@ go 1.21
 require (
 	github.com/ActiveState/termtest/conpty v0.5.0
 	github.com/creack/pty v1.1.21
+	github.com/fsnotify/fsnotify v1.7.0
 	github.com/gliderlabs/ssh v0.3.7
 	github.com/gorilla/websocket v1.5.3
 	github.com/hashicorp/yamux v0.1.1

go.sum

@@ -9,6 +9,8 @@ github.com/creack/pty v1.1.21/go.mod h1:MOBLtS5ELjhRRrroQr9kyvTxUAFNvYEK993ew/Vr
 github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
 github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/fsnotify/fsnotify v1.7.0 h1:8JEhPFa5W2WU7YfeZzPNqzMP6Lwt7L2715Ggo0nosvA=
+github.com/fsnotify/fsnotify v1.7.0/go.mod h1:40Bi/Hjc2AVfZrqy+aj+yEI+/bRxZnMJyTJwOpGvigM=
 github.com/gliderlabs/ssh v0.3.7 h1:iV3Bqi942d9huXnzEF2Mt+CY9gLu8DNM4Obd+8bODRE=
 github.com/gliderlabs/ssh v0.3.7/go.mod h1:zpHEXBstFnQYtGnB8k8kQLol82umzn/2/snG7alWVD8=
 github.com/gorilla/websocket v1.5.3 h1:saDtZ6Pbx/0u+bgYQ3q96pZgCzfhKXGPqt7kZ72aNNg=

pkg/agent/session.go

@@ -13,6 +13,15 @@ import (
 	_ "embed"
 )
 
+// TDDO fix concurrency
+// All methods put a message on a channel
+//
+// Using a channel of functions will work.
+// When default is used, channel will block always and thereby
+// effectively serializing everything.
+//
+// make(chan func())
+
 // global configuration
 
 type AgentState struct {
@@ -168,6 +177,7 @@ func (state *AgentState) expiryTime(filename string) time.Time {
 //  4. If the last user logs out, the aagent will exit immediately if no .hold file is
 //     present. Otherwise it will exit after the epxiry time. This allows users to
 //     reconnect later.
+
 func check() {
 	now := time.Now()