# `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.

`stat.``ST_NLINK`

  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。

`stat.``UF_NOUNLINK`

  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。

`stat.``SF_NOUNLINK`

  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_SYMLINK`
`stat.``IO_REPARSE_TAG_MOUNT_POINT`
`stat.``IO_REPARSE_TAG_APPEXECLINK`

  3.8 新版功能.