Python os.access() Method

Python File(文件) 方法 Python OS File/Directory Methods

Overview

The os.access() method uses the current uid/gid to attempt to access the path. Most operations use the effective uid/gid, so the runtime environment can attempt in the suid/sgid environment.

Syntax

access()The method syntax is as follows:

os.access(path, mode);

Parameters

path-- The path to check for access permissions.
mode-- mode is F_OK, test whether the path exists, or it can be one or more of R_OK, W_OK, and X_OK.
- os.F_OK:As the mode parameter of access(), test whether the path exists.
- os.R_OK:Included in the mode parameter of access(), test whether the path is readable.
- os.W_OKIncluded in the mode parameter of access(), test whether the path is writable.
- os.X_OKIncluded in the mode parameter of access(), test whether the path is executable.

Return Value

Returns True if access is allowed, otherwise returns False.

Example

The following example demonstrates the use of the access() method:

#!/usr/bin/python
# -*- coding: UTF-8 -*-

import os, sys

# 假定 /tmp/foo.txt 文件存在，并有读写权限

ret = os.access("/tmp/foo.txt", os.F_OK)
print "F_OK - 返回值 %s"% ret

ret = os.access("/tmp/foo.txt", os.R_OK)
print "R_OK - 返回值 %s"% ret

ret = os.access("/tmp/foo.txt", os.W_OK)
print "W_OK - 返回值 %s"% ret

ret = os.access("/tmp/foo.txt", os.X_OK)
print "X_OK - 返回值 %s"% ret

The output of the above program is:

F_OK - 返回值 True
R_OK - 返回值 True
W_OK - 返回值 True
X_OK - 返回值 False