diff options
author | Brad Fitzpatrick <bradfitz@golang.org> | 2011-04-22 09:30:30 -0700 |
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committer | Brad Fitzpatrick <bradfitz@golang.org> | 2011-04-22 09:30:30 -0700 |
commit | 4335bee42e5c45b3d6cb9919af9867d94c251486 (patch) | |
tree | 857ef68d0b8003d7b159c33e732885c41748b58b | |
parent | 81cfb4ec2b37a296722de4172a4a0d29cce06961 (diff) | |
download | go-4335bee42e5c45b3d6cb9919af9867d94c251486.tar.gz go-4335bee42e5c45b3d6cb9919af9867d94c251486.zip |
os/user: new package to look up users
Only for Unix presently. Other operating systems
are stubbed out, as well as arm (lacks cgo).
R=rsc, r, bradfitzwork
CC=golang-dev
https://golang.org/cl/4440057
-rw-r--r-- | src/pkg/Makefile | 1 | ||||
-rw-r--r-- | src/pkg/os/user/Makefile | 26 | ||||
-rw-r--r-- | src/pkg/os/user/lookup_stubs.go | 19 | ||||
-rw-r--r-- | src/pkg/os/user/lookup_unix.go | 104 | ||||
-rw-r--r-- | src/pkg/os/user/user.go | 35 | ||||
-rw-r--r-- | src/pkg/os/user/user_test.go | 61 |
6 files changed, 246 insertions, 0 deletions
diff --git a/src/pkg/Makefile b/src/pkg/Makefile index d3ec7dd290..44d4473fcb 100644 --- a/src/pkg/Makefile +++ b/src/pkg/Makefile @@ -120,6 +120,7 @@ DIRS=\ netchan\ os\ os/signal\ + os/user\ patch\ path\ path/filepath\ diff --git a/src/pkg/os/user/Makefile b/src/pkg/os/user/Makefile new file mode 100644 index 0000000000..731f7999ac --- /dev/null +++ b/src/pkg/os/user/Makefile @@ -0,0 +1,26 @@ +# Copyright 2011 The Go Authors. All rights reserved. +# Use of this source code is governed by a BSD-style +# license that can be found in the LICENSE file. + +include ../../../Make.inc + +TARG=os/user +GOFILES=\ + user.go\ + +ifneq ($(GOARCH),arm) +CGOFILES_linux=\ + lookup_unix.go +CGOFILES_freebsd=\ + lookup_unix.go +CGOFILES_darwin=\ + lookup_unix.go +endif + +ifneq ($(CGOFILES_$(GOOS)),) +CGOFILES+=$(CGOFILES_$(GOOS)) +else +GOFILES+=lookup_stubs.go +endif + +include ../../../Make.pkg diff --git a/src/pkg/os/user/lookup_stubs.go b/src/pkg/os/user/lookup_stubs.go new file mode 100644 index 0000000000..2f08f70fd5 --- /dev/null +++ b/src/pkg/os/user/lookup_stubs.go @@ -0,0 +1,19 @@ +// Copyright 2011 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +package user + +import ( + "fmt" + "os" + "runtime" +) + +func Lookup(username string) (*User, os.Error) { + return nil, fmt.Errorf("user: Lookup not implemented on %s/%s", runtime.GOOS, runtime.GOARCH) +} + +func LookupId(int) (*User, os.Error) { + return nil, fmt.Errorf("user: LookupId not implemented on %s/%s", runtime.GOOS, runtime.GOARCH) +} diff --git a/src/pkg/os/user/lookup_unix.go b/src/pkg/os/user/lookup_unix.go new file mode 100644 index 0000000000..678de802b5 --- /dev/null +++ b/src/pkg/os/user/lookup_unix.go @@ -0,0 +1,104 @@ +// Copyright 2011 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +package user + +import ( + "fmt" + "os" + "runtime" + "strings" + "unsafe" +) + +/* +#include <unistd.h> +#include <sys/types.h> +#include <pwd.h> +#include <stdlib.h> + +static int mygetpwuid_r(int uid, struct passwd *pwd, + char *buf, size_t buflen, struct passwd **result) { + return getpwuid_r(uid, pwd, buf, buflen, result); +} +*/ +import "C" + +// Lookup looks up a user by username. If the user cannot be found, +// the returned error is of type UnknownUserError. +func Lookup(username string) (*User, os.Error) { + return lookup(-1, username, true) +} + +// LookupId looks up a user by userid. If the user cannot be found, +// the returned error is of type UnknownUserIdError. +func LookupId(uid int) (*User, os.Error) { + return lookup(uid, "", false) +} + +func lookup(uid int, username string, lookupByName bool) (*User, os.Error) { + var pwd C.struct_passwd + var result *C.struct_passwd + + var bufSize C.long + if runtime.GOOS == "freebsd" { + // FreeBSD doesn't have _SC_GETPW_R_SIZE_MAX + // and just returns -1. So just use the same + // size that Linux returns + bufSize = 1024 + } else { + bufSize = C.sysconf(C._SC_GETPW_R_SIZE_MAX) + if bufSize <= 0 || bufSize > 1<<20 { + return nil, fmt.Errorf("user: unreasonable _SC_GETPW_R_SIZE_MAX of %d", bufSize) + } + } + buf := C.malloc(C.size_t(bufSize)) + defer C.free(buf) + var rv C.int + if lookupByName { + nameC := C.CString(username) + defer C.free(unsafe.Pointer(nameC)) + rv = C.getpwnam_r(nameC, + &pwd, + (*C.char)(buf), + C.size_t(bufSize), + &result) + if rv != 0 { + return nil, fmt.Errorf("user: lookup username %s: %s", username, os.Errno(rv)) + } + if result == nil { + return nil, UnknownUserError(username) + } + } else { + // mygetpwuid_r is a wrapper around getpwuid_r to + // to avoid using uid_t because C.uid_t(uid) for + // unknown reasons doesn't work on linux. + rv = C.mygetpwuid_r(C.int(uid), + &pwd, + (*C.char)(buf), + C.size_t(bufSize), + &result) + if rv != 0 { + return nil, fmt.Errorf("user: lookup userid %d: %s", uid, os.Errno(rv)) + } + if result == nil { + return nil, UnknownUserIdError(uid) + } + } + u := &User{ + Uid: int(pwd.pw_uid), + Gid: int(pwd.pw_gid), + Username: C.GoString(pwd.pw_name), + Name: C.GoString(pwd.pw_gecos), + HomeDir: C.GoString(pwd.pw_dir), + } + // The pw_gecos field isn't quite standardized. Some docs + // say: "It is expected to be a comma separated list of + // personal data where the first item is the full name of the + // user." + if i := strings.Index(u.Name, ","); i >= 0 { + u.Name = u.Name[:i] + } + return u, nil +} diff --git a/src/pkg/os/user/user.go b/src/pkg/os/user/user.go new file mode 100644 index 0000000000..dd009211d7 --- /dev/null +++ b/src/pkg/os/user/user.go @@ -0,0 +1,35 @@ +// Copyright 2011 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +// Package user allows user account lookups by name or id. +package user + +import ( + "strconv" +) + +// User represents a user account. +type User struct { + Uid int // user id + Gid int // primary group id + Username string + Name string + HomeDir string +} + +// UnknownUserIdError is returned by LookupId when +// a user cannot be found. +type UnknownUserIdError int + +func (e UnknownUserIdError) String() string { + return "user: unknown userid " + strconv.Itoa(int(e)) +} + +// UnknownUserError is returned by Lookup when +// a user cannot be found. +type UnknownUserError string + +func (e UnknownUserError) String() string { + return "user: unknown user " + string(e) +} diff --git a/src/pkg/os/user/user_test.go b/src/pkg/os/user/user_test.go new file mode 100644 index 0000000000..2c142bf181 --- /dev/null +++ b/src/pkg/os/user/user_test.go @@ -0,0 +1,61 @@ +// Copyright 2011 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +package user + +import ( + "os" + "reflect" + "runtime" + "syscall" + "testing" +) + +func skip(t *testing.T) bool { + if runtime.GOARCH == "arm" { + t.Logf("user: cgo not implemented on arm; skipping tests") + return true + } + + if runtime.GOOS == "linux" || runtime.GOOS == "freebsd" || runtime.GOOS == "darwin" { + return false + } + + t.Logf("user: Lookup not implemented on %s; skipping test", runtime.GOOS) + return true +} + +func TestLookup(t *testing.T) { + if skip(t) { + return + } + + // Test LookupId on the current user + uid := syscall.Getuid() + u, err := LookupId(uid) + if err != nil { + t.Fatalf("LookupId: %v", err) + } + if e, g := uid, u.Uid; e != g { + t.Errorf("expected Uid of %d; got %d", e, g) + } + fi, err := os.Stat(u.HomeDir) + if err != nil || !fi.IsDirectory() { + t.Errorf("expected a valid HomeDir; stat(%q): err=%v, IsDirectory=%v", err, fi.IsDirectory()) + } + if u.Username == "" { + t.Fatalf("didn't get a username") + } + + // Test Lookup by username, using the username from LookupId + un, err := Lookup(u.Username) + if err != nil { + t.Fatalf("Lookup: %v", err) + } + if !reflect.DeepEqual(u, un) { + t.Errorf("Lookup by userid vs. name didn't match\n"+ + "LookupId(%d): %#v\n"+ + "Lookup(%q): %#v\n",uid, u, u.Username, un) + } +} |