1. Jason R. Coombs
  2. cpython-issue10639


cpython-issue10639 / Doc / library / stat.rst

:mod:`stat` --- Interpreting :func:`stat` results

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

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

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

Normally, you would use the :func:`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 :cfunc:`stat` system call for each test. These are also useful when checking for information about a file that isn't handled by :mod:`os.path`, like the tests for block and character devices.


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
            # Unknown file type, print a message
            print 'Skipping %s' % pathname

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

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

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

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 :func:`os.stat`, :func:`os.fstat`, or :func:`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 :data:`ST_MODE` field.

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

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

The following flags can be used in the flags argument of :func:`os.chflags`:

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