Python os.readlink() Method

Python is an exceptional programming language with loads of features and methods. One of the most useful modules in the Python ecosystem is the os module.

This module provides an efficient and portable way of interacting with the operating system. One of the methods from this module is the readlink() method which allows us to read the contents of a symbolic link.

A symbolic link, also known as a soft link or symlink, is a special kind of file that points to another file or directory. You an think of it as a shortcut in the Windows OS.

Python os.readlink() Method

The os.readlink() function takes the path to the symbolic link and returns a string representing the path to the actual file or directory. This is shown in the function syntax as shown:

os.readlink(path)

NOTE: The method does not actually follow the symlink. Instead, it simply returns the path to where the symbolic link points to and not the actual contents of the file or directory.

Using the readlink() Method

Let us explore how we can us this method.

Import the OS Module

Before we can use the os.readlink() method, we need to import the os module.

import os

Basic Function Usage

Let us start with a simple case of how to use this function.

Suppose we have a symbolic link called sbin in the / directory. We can use the readlink() function to see where the symlink points to as demonstrated in the example below:

import os

link_path = '/sbin'
original_path = os.readlink(link_path)

print(f'The symbolic link {link_path} points to: {original_path}')

The code above should return an output as shown:

The symbolic link /sbin points to: usr/sbin

Handling Errors

As with any method that allows you to interact with the filesystem and the os, there's a large potentiality for errors.

For example, if you attempt to use the readlink() method on a file or directory that is not a symlink, the method returns an OSError. We can try and fix this issue by using a try/except block as shown:

import os

try:
    link_path = '/etc'
    original_path = os.readlink(link_path)
    print(f'The symbolic link {link_path} points to: {original_path}')
except OSError:
    print(f'{link_path} is not a symbolic link.')

Since the provided path /etc, the code should raise an error which execute the except block as:

.etc is not a symbolic link

Getting the Absolute Path

To get the full or absolute path of the file or directory the symbolic link is pointing to, you can use os.path.abspath() in conjunction with os.readlink():

import os

link_path = '/sbin'
target_path = os.readlink(link_path)
full_path = os.path.abspath(target_path)

print(f'The symbolic link {link_path} points to: {full_path}')

This will output the absolute path of the file or directory that the symlink is pointing to

The symbolic link /sbin points to: /sbin

Conclusion

In this tutorial, we explored how we can get the file or link pointed by a symbolic link by using the os.readlink() method in Python. This is handy tool when working with symbolic links in your system, allowing you to handle file system operations more efficiently.