stat --- Interpreting stat() results

源代码： Lib/stat.py

The stat module defines constants and functions for interpreting the results of os.stat(), os.fstat() and os.lstat() (if they exist). For complete details about the stat(), fstat() and lstat() calls, consult the documentation for your system.

在 3.4 版更改: The stat module is backed by a C implementation.

The stat module defines the following functions to test for specific file types:

stat.S_ISDIR(mode)

Return non-zero if the mode is from a directory.

stat.S_ISCHR(mode)

Return non-zero if the mode is from a character special device file.

stat.S_ISBLK(mode)

Return non-zero if the mode is from a block special device file.

stat.S_ISREG(mode)

Return non-zero if the mode is from a regular file.

stat.S_ISFIFO(mode)

Return non-zero if the mode is from a FIFO (named pipe).

stat.S_ISLNK(mode)

Return non-zero if the mode is from a symbolic link.

stat.S_ISSOCK(mode)

Return non-zero if the mode is from a socket.

stat.S_ISDOOR(mode)

Return non-zero if the mode is from a door.

3.4 新版功能.

stat.S_ISPORT(mode)

Return non-zero if the mode is from an event port.

3.4 新版功能.

stat.S_ISWHT(mode)

Return non-zero if the mode is from a whiteout.

3.4 新版功能.

Two additional functions are defined for more general manipulation of the file's mode:

stat.S_IMODE(mode)

Return the portion of the file's mode that can be set by os.chmod()---that is, the file's permission bits, plus the sticky bit, set-group-id, and set-user-id bits (on systems that support them).

stat.S_IFMT(mode)

Return the portion of the file's mode that describes the file type (used by the S_IS*() functions above).

Normally, you would use the os.path.is*() functions for testing the type of a file; the functions here are useful when you are doing multiple tests of the same file and wish to avoid the overhead of the stat() system call for each test. These are also useful when checking for information about a file that isn't handled by os.path, like the tests for block and character devices.

示例:

import os, sys
from stat import *

def walktree(top, callback):
    '''recursively descend the directory tree rooted at top,
       calling the callback function for each regular file'''

    for f in os.listdir(top):
        pathname = os.path.join(top, f)
        mode = os.stat(pathname).st_mode
        if S_ISDIR(mode):
            # It's a directory, recurse into it
            walktree(pathname, callback)
        elif S_ISREG(mode):
            # It's a file, call the callback function
            callback(pathname)
        else:
            # Unknown file type, print a message
            print('Skipping %s' % pathname)

def visitfile(file):
    print('visiting', file)

if __name__ == '__main__':
    walktree(sys.argv[1], visitfile)

An additional utility function is provided to convert a file's mode in a human readable string:

stat.filemode(mode)

Convert a file's mode to a string of the form '-rwxrwxrwx'.

3.3 新版功能.

在 3.4 版更改: The function supports S_IFDOOR, S_IFPORT and S_IFWHT.

All the variables below are simply symbolic indexes into the 10-tuple returned by os.stat(), os.fstat() or os.lstat().

stat.ST_MODE

inode保护模式。

stat.ST_INO

Inode 号

stat.ST_DEV

Device inode resides on.

Number of links to the inode.

stat.ST_UID

所有者的用户ID。

stat.ST_GID

所有者的用户组ID。

stat.ST_SIZE

Size in bytes of a plain file; amount of data waiting on some special files.

stat.ST_ATIME

上次访问的时间。

stat.ST_MTIME

上次修改的时间。

stat.ST_CTIME

The "ctime" as reported by the operating system. On some systems (like Unix) is the time of the last metadata change, and, on others (like Windows), is the creation time (see platform documentation for details).

The interpretation of "file size" changes according to the file type. For plain files this is the size of the file in bytes. For FIFOs and sockets under most flavors of Unix (including Linux in particular), the "size" is the number of bytes waiting to be read at the time of the call to os.stat(), os.fstat(), or os.lstat(); this can sometimes be useful, especially for polling one of these special files after a non-blocking open. The meaning of the size field for other character and block devices varies more, depending on the implementation of the underlying system call.

The variables below define the flags used in the ST_MODE field.

Use of the functions above is more portable than use of the first set of flags:

stat.S_IFSOCK

套接字

stat.S_IFLNK

符号链接。

stat.S_IFREG

普通文件。

stat.S_IFBLK

块设备

stat.S_IFDIR

目录

stat.S_IFCHR

字符设备。

stat.S_IFIFO

先进先出

stat.S_IFDOOR

Door.

3.4 新版功能.

stat.S_IFPORT

事件端口。

3.4 新版功能.

stat.S_IFWHT

Whiteout.

3.4 新版功能.

注解

S_IFDOOR, S_IFPORT or S_IFWHT are defined as 0 when the platform does not have support for the file types.

The following flags can also be used in the mode argument of os.chmod():

stat.S_ISUID

设置UID位。

stat.S_ISGID

Set-group-ID bit. This bit has several special uses. For a directory it indicates that BSD semantics is to be used for that directory: files created there inherit their group ID from the directory, not from the effective group ID of the creating process, and directories created there will also get the S_ISGID bit set. For a file that does not have the group execution bit (S_IXGRP) set, the set-group-ID bit indicates mandatory file/record locking (see also S_ENFMT).

stat.S_ISVTX

Sticky bit. When this bit is set on a directory it means that a file in that directory can be renamed or deleted only by the owner of the file, by the owner of the directory, or by a privileged process.

stat.S_IRWXU

文件所有者权限的掩码。

stat.S_IRUSR

所有者具有读取权限。

stat.S_IWUSR

所有者具有写入权限。

stat.S_IXUSR

所有者具有执行权限。

stat.S_IRWXG

组权限的掩码。

stat.S_IRGRP

组具有读取权限。

stat.S_IWGRP

组具有写入权限。

stat.S_IXGRP

组具有执行权限。

stat.S_IRWXO

其他人（不在组中）的权限掩码。

stat.S_IROTH

其他人具有读取权限。

stat.S_IWOTH

其他人具有写入权限。

stat.S_IXOTH

其他人具有执行权限。

stat.S_ENFMT

System V file locking enforcement. This flag is shared with S_ISGID: file/record locking is enforced on files that do not have the group execution bit (S_IXGRP) set.

stat.S_IREAD

Unix V7 synonym for S_IRUSR.

stat.S_IWRITE

Unix V7 synonym for S_IWUSR.

stat.S_IEXEC

Unix V7 synonym for S_IXUSR.

The following flags can be used in the flags argument of os.chflags():

stat.UF_NODUMP

不要转储文件。

stat.UF_IMMUTABLE

文件不能更改。

stat.UF_APPEND

文件只能附加到。

stat.UF_OPAQUE

当通过联合堆栈查看时，目录是不透明的。

文件不能重命名或删除。

stat.UF_COMPRESSED

文件是压缩存储的（Mac OS X 10.6+）。

stat.UF_HIDDEN

文件不能显示在GUI 中（Mac OS X 10.5+）。

stat.SF_ARCHIVED

文件可能已存档。

stat.SF_IMMUTABLE

文件不能更改。

stat.SF_APPEND

文件只能附加到。

文件不能重命名或删除。

stat.SF_SNAPSHOT

文件有一个快照文件

See the *BSD or Mac OS systems man page chflags(2) for more information.

On Windows, the following file attribute constants are available for use when testing bits in the st_file_attributes member returned by os.stat(). See the Windows API documentation for more detail on the meaning of these constants.

stat.FILE_ATTRIBUTE_ARCHIVE
stat.FILE_ATTRIBUTE_COMPRESSED
stat.FILE_ATTRIBUTE_DEVICE
stat.FILE_ATTRIBUTE_DIRECTORY
stat.FILE_ATTRIBUTE_ENCRYPTED
stat.FILE_ATTRIBUTE_HIDDEN
stat.FILE_ATTRIBUTE_INTEGRITY_STREAM
stat.FILE_ATTRIBUTE_NORMAL
stat.FILE_ATTRIBUTE_NOT_CONTENT_INDEXED
stat.FILE_ATTRIBUTE_NO_SCRUB_DATA
stat.FILE_ATTRIBUTE_OFFLINE
stat.FILE_ATTRIBUTE_READONLY
stat.FILE_ATTRIBUTE_REPARSE_POINT
stat.FILE_ATTRIBUTE_SPARSE_FILE
stat.FILE_ATTRIBUTE_SYSTEM
stat.FILE_ATTRIBUTE_TEMPORARY
stat.FILE_ATTRIBUTE_VIRTUAL

3.5 新版功能.

On Windows, the following constants are available for comparing against the st_reparse_tag member returned by os.lstat(). These are well-known constants, but are not an exhaustive list.

stat.IO_REPARSE_TAG_MOUNT_POINT

3.8 新版功能.