extract relative & absolute paths from CSS and JS files

extract_links.py

import re
import os

# extract relative & absolute paths from css and js files
# warning: assumes all assets in javascript are within either backticks, single or double quotes.

asset_path = './downloaded/'    # location of assets to extract URLs from
outfile    = 'asset_links.txt'  # output file
chr_b      = ''  # characters to be printed before the asset link. Leave empty ('') if none.
chr_a      = ''  # characters to be printed after the asset link. Leave empty ('') if none.
count      = 0


def process_css(asset_path, outfile):

    global count

    url_pattern = re.compile(r'url\((.*?)\)')
    asset_paths = []

    for root, directories, files in os.walk(asset_path):
        for file_name in files:
            if file_name.endswith('.css'):
                css_file_path = os.path.join(root, file_name)
                with open(css_file_path, 'r') as css_file:
                    css_content = css_file.read()
                    matches = url_pattern.findall(css_content)
                    asset_paths += [match.strip('\'"') for match in matches]

    with open(outfile, 'a') as output_file:
        for asset_path in asset_paths:
            file_string = str(chr_b) + str(asset_path) + str(chr_a)
            output_file.write(file_string + '\n')
            print(file_string)
            count += 1


def extract_js_asset_paths(js_content):

    pattern = r'([\'"`])((https?:\/\/\S+)|(\.{1,2}\/\S+?))\1'
    asset_paths = re.findall(pattern, js_content)
    asset_paths = [path[1] for path in asset_paths]
    
    return asset_paths


def process_javascript(asset_path, outfile):

    global count

    for root, directories, files in os.walk(asset_path):
        for filename in files:
            if filename.endswith('.js'):
                file_path = os.path.join(root, filename)

                with open(file_path, 'r') as file:
                    js_content = file.read()

                paths = extract_js_asset_paths(js_content)

                with open(outfile, 'a') as output:
                    for path in paths:
                        file_string = str(chr_b) + str(path) + str(chr_a)
                        output.write(file_string + '\n')
                        print(file_string)
                        count += 1


if __name__ == '__main__':
    process_css(asset_path, outfile)
    process_javascript(asset_path, outfile)
    print('\nProcessed ' + str(count) + ' assets.')