In order to extract links from a file we can use regular expressions
(?:(?:https?|ftp):\/\/)?[\w/\-?=%.]+\.[\w/\-?=%.]+
This will match all the urls in the file and we can write a python script to extract the urls.
text = "<CONTAINING URLS>"
urls = re.findall('(?:(?:https?|ftp):\/\/)?[\w/\-?=%.]+\.[\w/\-?=%.]+', text)
print(urls)