feat: «Здесь» from a machine's terminal opens the file pane in the terminal's folder (asked of the agent); Аккаунт › Вид can turn «Здесь» back to the home folder. Version 0.2.1

internal/agent/session.go

@@ -26,6 +26,8 @@ func (a *Agent) runTerminal(parent context.Context, sid, user, dir string) {
 		return
 	}
 	log.Printf("term %s: shell started (user %q)", sid, user)
+	termsBySID.Store(sid, term)
+	defer termsBySID.Delete(sid)
 	a.bridgeStream(parent, sid, term, term.Resize)
 	log.Printf("term %s: ended", sid)
 }

internal/agent/termcwd.go

@@ -0,0 +1,62 @@
+package agent
+
+import (
+	"errors"
+	"os"
+	"os/exec"
+	"runtime"
+	"strconv"
+	"strings"
+	"sync"
+
+	"golang.org/x/sys/unix"
+)
+
+// termsBySID are the running terminals by their session, so the panel can
+// ask where one of them is.
+var termsBySID sync.Map // sid -> *PTY
+
+// Cwd is the folder the terminal is in now: that of the program in front
+// (the shell, or what it runs), else of the shell itself.
+func (p *PTY) Cwd() (string, error) {
+	pid := 0
+	if g, err := unix.IoctlGetInt(int(p.f.Fd()), unix.TIOCGPGRP); err == nil && g > 0 {
+		pid = g
+	}
+	if pid > 0 {
+		if d, err := procCwd(pid); err == nil {
+			return d, nil
+		}
+	}
+	return procCwd(p.cmd.Process.Pid)
+}
+
+// procCwd is a process's working folder: /proc on Linux, lsof elsewhere.
+func procCwd(pid int) (string, error) {
+	if runtime.GOOS == "linux" {
+		return os.Readlink("/proc/" + strconv.Itoa(pid) + "/cwd")
+	}
+	out, err := exec.Command("lsof", "-a", "-p", strconv.Itoa(pid), "-d", "cwd", "-Fn").Output()
+	if err != nil {
+		return "", err
+	}
+	for _, l := range strings.Split(string(out), "\n") {
+		if strings.HasPrefix(l, "n/") {
+			return l[1:], nil
+		}
+	}
+	return "", errors.New("папка терминала не найдена")
+}
+
+// termCwd answers the panel: where the terminal of session sid is now.
+func termCwd(sid string) (any, error) {
+	v, ok := termsBySID.Load(sid)
+	if !ok {
+		return nil, errors.New("терминал не найден")
+	}
+	d, err := v.(*PTY).Cwd()
+	if err != nil {
+		return nil, err
+	}
+	return map[string]string{"path": d}, nil
+}

internal/agent/terminal_test.go

@@ -1,11 +1,14 @@
 package agent
 
 import (
+	"io"
 	"os"
 	"path/filepath"
 	"strings"
 	"testing"
 	"time"
+
+	"github.com/x-grk/longpolling-remote-access/internal/proto"
 )
 
 // A terminal opened with a folder starts its shell there; a folder that is
@@ -60,3 +63,53 @@ func ptyPwd(t *testing.T, dir string) string {
 	t.Fatalf("no pwd in %q", out.String())
 	return ""
 }
+
+// A terminal tells the folder its shell is in now, after a cd.
+func TestPTYCwd(t *testing.T) {
+	dir, err := filepath.EvalSymlinks(t.TempDir())
+	if err != nil {
+		t.Fatal(err)
+	}
+	sub := filepath.Join(dir, "next one")
+	if err := os.Mkdir(sub, 0o755); err != nil {
+		t.Fatal(err)
+	}
+	t.Setenv("SHELL", "/bin/sh")
+	p, err := StartPTY("", dir)
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer p.Close()
+	go func() { _, _ = io.Copy(io.Discard, p) }()
+	if _, err := p.Write([]byte("cd 'next one'\n")); err != nil {
+		t.Fatal(err)
+	}
+	var got string
+	for i := 0; i < 50; i++ {
+		if got, err = p.Cwd(); err == nil && got == sub {
+			return
+		}
+		time.Sleep(100 * time.Millisecond)
+	}
+	t.Fatalf("Cwd = %q, %v; want %q", got, err, sub)
+}
+
+// The panel asks for a terminal's folder by its session.
+func TestTermCwdTask(t *testing.T) {
+	dir, _ := filepath.EvalSymlinks(t.TempDir())
+	t.Setenv("SHELL", "/bin/sh")
+	p, err := StartPTY("", dir)
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer p.Close()
+	termsBySID.Store("s1", p)
+	defer termsBySID.Delete("s1")
+	res, err := dispatchTask(proto.TaskEnvelope{Type: proto.TaskTermCwd, Args: []byte(`{"session":"s1"}`)})
+	if err != nil || res.(map[string]string)["path"] != dir {
+		t.Fatalf("term.cwd = %v, %v; want %q", res, err, dir)
+	}
+	if _, err := dispatchTask(proto.TaskEnvelope{Type: proto.TaskTermCwd, Args: []byte(`{"session":"nope"}`)}); err == nil {
+		t.Fatal("an unknown session has a folder")
+	}
+}

internal/agent/users.go

@@ -41,6 +41,10 @@ func dispatchTask(env proto.TaskEnvelope) (any, error) {
 		return nil, addUser(a)
 	case proto.TaskDBTables, proto.TaskDBRows, proto.TaskDBSet, proto.TaskDBAdd, proto.TaskDBDel, proto.TaskDBSQL:
 		return dbTask(env)
+	case proto.TaskTermCwd:
+		var a proto.TermCwdArgs
+		_ = json.Unmarshal(env.Args, &a)
+		return termCwd(a.Session)
 	}
 	return dispatchFS(env)
 }