Imported Upstream version 2011.04.27upstream/2011.04.27

1 files changed, 104 insertions, 0 deletions

diff --git a/src/pkg/os/user/lookup_unix.go b/src/pkg/os/user/lookup_unix.go
new file mode 100644
index 000000000..678de802b
--- /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
+}