如何使用python在* nix上获得文件的权限掩码,如644或755?
是否有用于执行此操作的函数或类?非常感谢!
[os.stat
是stat(2)系统调用接口的包装。
>>> import os
>>> from stat import *
>>> os.stat("test.txt") # returns 10-tupel, you really want the 0th element ...
posix.stat_result(st_mode=33188, st_ino=57197013, \
st_dev=234881026L, st_nlink=1, st_uid=501, st_gid=20, st_size=0, \
st_atime=1300354697, st_mtime=1300354697, st_ctime=1300354697)
>>> os.stat("test.txt")[ST_MODE] # this is an int, but we like octal ...
33188
>>> oct(os.stat("test.txt")[ST_MODE])
'0100644'
从这里您将了解典型的八进制权限。
S_IRWXU 00700 mask for file owner permissions
S_IRUSR 00400 owner has read permission
S_IWUSR 00200 owner has write permission
S_IXUSR 00100 owner has execute permission
S_IRWXG 00070 mask for group permissions
S_IRGRP 00040 group has read permission
S_IWGRP 00020 group has write permission
S_IXGRP 00010 group has execute permission
S_IRWXO 00007 mask for permissions for others (not in group)
S_IROTH 00004 others have read permission
S_IWOTH 00002 others have write permission
S_IXOTH 00001 others have execute permission
您实际上只对较低的[[bits感兴趣,所以您可以砍掉其余的:
>>> oct(os.stat("test.txt")[ST_MODE])[-3:]
'644'
>>> # or better
>>> oct(os.stat("test.txt").st_mode & 0o777)
边注:上部确定文件类型,例如:
S_IFMT 0170000 bitmask for the file type bitfields S_IFSOCK 0140000 socket S_IFLNK 0120000 symbolic link S_IFREG 0100000 regular file S_IFBLK 0060000 block device S_IFDIR 0040000 directory S_IFCHR 0020000 character device S_IFIFO 0010000 FIFO S_ISUID 0004000 set UID bit S_ISGID 0002000 set-group-ID bit (see below) S_ISVTX 0001000 sticky bit (see below)
stat.S_IMODE(os.lstat("file").st_mode)
os.lstat函数将在文件为符号链接的情况下为您提供链接本身的模式,而os.stat将取消引用链接。因此,我发现os.lstat最有用。这是一个示例,给定常规文件“ testfile”并链接到后者“ testlink”:
import stat import os print oct(stat.S_IMODE(os.lstat("testlink").st_mode)) print oct(stat.S_IMODE(os.stat("testlink").st_mode))
此脚本为我输出以下内容:
0777 0666
但请阅读有关可能的安全问题的文档
例如,检查具有读取/写入权限的文件test.dat的权限os.access("test.dat",os.R_OK)
>>> True
#Execute permissions
os.access("test.dat",os.X_OK)
>>> False
#And Combinations thereof
os.access("test.dat",os.R_OK or os.X_OK)
>>> True
os.access("test.dat",os.R_OK and os.X_OK)
>>> False
os.stat(filename)
,则始终可以插入结果。stats = os.stat('file.txt')
print stats.st_mode
可用模式为:
ls -l /tmp/temp.sh
-rw-r--r-- 1 * * 0 Mar 2 12:05 /tmp/temp.sh
os.access('/tmp/temp.sh',os.X_OK)
False
after changing the file permission to +x
chmod +x /tmp/temp.sh
ls -l /tmp/temp.sh
-rwxr-xr-x 1 * * 0 Mar 2 12:05 /tmp/temp.sh
os.access('/tmp/temp.sh',os.X_OK)
True
普通的Bash命令:
jlc@server:~/NetBeansProjects/LineReverse$ stat -c '%A %a %n' revline.c
-rw-rw-r-- 664 revline.c
然后使用Python:
>>> from subprocess import Popen, PIPE >>> fname = 'revline.c' >>> cmd = "stat -c '%A %a %n' " + fname >>> out = Popen(cmd, shell=True, stdout=PIPE).communicate()[0].split()[1].decode() >>> out '664'
这是如果您想搜索目录的另一种方法:
>>> from os import popen >>> cmd = "stat -c '%A %a %n' *" >>> fname = 'revline.c' >>> for i in popen(cmd): ... p, m, n = i.split() ... if n != fname: ... continue ... print(m) break ... 664 >>>