osusers.go: introduce Simulate() for glenda

This is just an quick and dirty hack, a better implementation exists.

osusers.go

@@ -5,6 +5,7 @@
 package ninep
 
 import (
+	"errors"
 	"os/user"
 	"strconv"
 	"sync"
@@ -19,6 +20,7 @@ type osUser struct {
 }
 
 type osUsers struct {
+	simulating *osUser
 	groups map[int]*osGroup
 	sync.Mutex
 }
@@ -48,6 +50,7 @@ func (g *osGroup) Members() []User { return nil }
 func initOsusers() {
 	OsUsers = new(osUsers)
 	OsUsers.groups = make(map[int]*osGroup)
+	OsUsers.simulating = nil
 }
 
 func newUser(u *user.User) *osUser {
@@ -60,6 +63,17 @@ func newUser(u *user.User) *osUser {
 	return &osUser{u, uid, gid}
 }
 
+func (up *osUsers) Simulate(u *user.User) error {
+	once.Do(initOsusers)
+	_, err := user.Lookup(u.Username)
+	if err != nil {
+		OsUsers.simulating = newUser(u)
+		return nil
+	}
+	return errors.New("cannot simulate an existing user.")
+}
+
+
 func (up *osUsers) Uid2User(uid int) User {
 	u, err := user.LookupId(strconv.Itoa(uid))
 	if err != nil {
@@ -69,6 +83,10 @@ func (up *osUsers) Uid2User(uid int) User {
 }
 
 func (up *osUsers) Uname2User(uname string) User {
+	once.Do(initOsusers)
+	if OsUsers.simulating != nil && uname == OsUsers.simulating.Username {
+		return OsUsers.simulating
+	}
 	u, err := user.Lookup(uname)
 	if err != nil {
 		return nil

srv/examples/ufs/ufs.go

@@ -7,14 +7,15 @@ package main
 import (
 	"flag"
 	"log"
+	"os/user"
 
+	"github.com/lionkov/ninep"
 	"github.com/lionkov/ninep/srv/ufs"
 )
 
 var (
 	debug = flag.Int("d", 0, "print debug messages")
 	addr = flag.String("addr", ":5640", "network address")
-	user = flag.String("user", "", "user name")
 )
 
 func main() {
@@ -24,12 +25,14 @@ func main() {
 	ufs.Id = "ufs"
 	ufs.Debuglevel = *debug
 	ufs.Start(ufs)
-	if *user != "" {
-		u := ufs.Upool.Uname2User(*user)
-		if u == nil {
-			log.Printf("Warning: Adding %v failed", *user)
-		}
+
+	u, uerr := user.Current()
+	if uerr != nil {
+		log.Fatalln(uerr)
 	}
+	u.Username = "glenda"
+	u.HomeDir = "/usr/glenda"
+	ninep.OsUsers.Simulate(u)
 
 	err := ufs.StartNetListener("tcp", *addr)
 	if err != nil {