how to find the target file's full(absolute path) of the symbolic link or soft link in python

Question

when i give ls -l /etc/fonts/conf.d/70-yes-bitmaps.conf

lrwxrwxrwx <snip> /etc/fonts/conf.d/70-yes-bitmaps.conf -> ../conf.avail/70-yes-bitmaps.conf

so for a symbolic link or soft link, how to find the target file's full(absolute path) in python,

If i use

os.readlink('/etc/fonts/conf.d/70-yes-bitmaps.conf')

it outputs

../conf.avail/70-yes-bitmaps.conf

but i need the absolute path not the relative path, so my desired output must be,

/etc/fonts/conf.avail/70-yes-bitmaps.conf

how to replace the .. with the actual full path of the parent directory of the symbolic link or soft link file.

Irruptive

os.readlink should work on ubuntu/windows, python 3.5. Just tested it: https://mcmap.net/q/239384/-how-to-find-the-target-file-39-s-full-absolute-path-of-the-symbolic-link-or-soft-link-in-python – Blooded

Answer 1

os.path.realpath(path)

os.path.realpath returns the canonical path of the specified filename, eliminating any symbolic links encountered in the path.

Umbrageous

os.path.realpath doesn't eliminate symbolic links in Python 3.2 under Windows 7. (A bug?) – Rodneyrodolfo

Hmmm... I see that this has been an open bug for 1.5 years: bugs.python.org/issue9949 – Rodneyrodolfo

Yup getting this same problem, 3 years later :c – Yancy

in Python3, if you're using a Path object, you can do the same thing by doing path.resolve() – Cabrera

If C:\\Users\\PP is a symlink to another directory, in Windows 10 using python 3.5, os.path.realpath("C:\\Users\PP")basically returns the symlink path, not the real path. – Blooded

The Windows issue is fixed in Python 3.8: "Changed in version 3.8: Symbolic links and junctions are now resolved on Windows." – Reputation

Note that this depends on your current directory. Docs say "On most platforms, this is equivalent to calling the function normpath() as follows: normpath(join(os.getcwd(), path))". – Goldsmith

This assumes that your working directory is at the file with the symlink – Teat

os.path.realpath and ls -l have different results on mount driver – Intermarriage

Answer 2

As unutbu says, os.path.realpath(path) should be the right answer, returning the canonical path of the specified filename, resolving any symbolic links to their targets. But it's broken under Windows.

I've created a patch for Python 3.2 to fix this bug, and uploaded it to:

http://bugs.python.org/issue9949

It fixes the realpath() function in Python32\Lib\ntpath.py

I've also put it on my server, here:

http://www.burtonsys.com/ntpath_fix_issue9949.zip

Unfortunately, the bug is present in Python 2.x, too, and I know of no fix for it there.

Rodneyrodolfo

os.path.realpath and ls -l have different results on mount driver – Intermarriage

Answer 3

http://docs.python.org/library/os.path.html#os.path.abspath

also joinpath() and normpath(), depending on whether you're in the current working directory, or you're working with things elsewhere. normpath() might be more direct for you.

Specifically:

os.path.normpath( 
  os.path.join( 
    os.path.dirname( '/etc/fonts/conf.d/70-yes-bitmaps.conf' ), 
    os.readlink('/etc/fonts/conf.d/70-yes-bitmaps.conf') 
  ) 
)

Sundowner

Be warned though: should you pass a path which is not a symlink to readlink it will get angry and give the following exception: OSError: [Errno 22] Invalid argument: 'your-path' – Reputation

Answer 4

I recommend using pathlib library for filesystem operations.

import pathlib

x = pathlib.Path('lol/lol/path')
x.resolve()

Documentation for Path.resolve(strict=False): make the path absolute, resolving any symlinks. A new path object is returned.

Crowded

Answer 5

On windows 10, python 3.5, os.readlink("C:\\Users\PP") where "C:\Users\PP" is a symbolic link (not a junction link) works.

It returns the absolute path to the directory.

This works on Ubuntu 16.04, python 3.5 as well.

Blooded

Answer 6

The documentation says to use os.path.join():

The result may be either an absolute or relative pathname; if it is relative, it may be converted to an absolute pathname using os.path.join(os.path.dirname(path), result).

Athalla

os.path.abspath ? – Boycott

Not needed, @dmitry_romanov. If you just called os.path.abspath(result), it wouldn't know where the path should start. That's why you need to pass in path. If result is already an absolute path, then join is smart. From the docs: "If a component is an absolute path, all previous components are thrown away and joining continues from the absolute path component." – Athalla