如何按名称更改目录的用户和组权限？

Question

os.chown正是我想要的,但我想按名称指定用户和组,而不是ID(我不知道它们是什么).我怎样才能做到这一点？

Answer 1

import pwd
import grp
import os

uid = pwd.getpwnam("nobody").pw_uid
gid = grp.getgrnam("nogroup").gr_gid
path = '/tmp/f.txt'
os.chown(path, uid, gid)

Answer 2

自Python 3.3起 https://docs.python.org/3.3/library/shutil.html#shutil.chown

import shutil
shutil.chown(path, user=None, group=None)

更改给定路径的所有者用户和/或组.

user可以是系统用户名或uid; 同样适用于群体.

至少需要一个参数.

可用性:Unix.

Answer 3

由于 Shutil 版本支持组可选，因此我将代码复制并粘贴到我的 Python2 项目中。

https://hg.python.org/cpython/file/tip/Lib/shutil.py#l1010

def chown(path, user=None, group=None):
    """Change owner user and group of the given path.

    user and group can be the uid/gid or the user/group names, and in that case,
    they are converted to their respective uid/gid.
    """

    if user is None and group is None:
        raise ValueError("user and/or group must be set")

    _user = user
    _group = group

    # -1 means don't change it
    if user is None:
        _user = -1
    # user can either be an int (the uid) or a string (the system username)
    elif isinstance(user, basestring):
        _user = _get_uid(user)
        if _user is None:
            raise LookupError("no such user: {!r}".format(user))

    if group is None:
        _group = -1
    elif not isinstance(group, int):
        _group = _get_gid(group)
        if _group is None:
            raise LookupError("no such group: {!r}".format(group))

    os.chown(path, _user, _group)