Add line number at the end of each line in a text file

Question

I have a text file which contains thousands of lines with same links. I want append the line number at the end of each line. For example;

https://example.com/
https://example.com/

these links would become:

https://example.com/1
https://example.com/2

and so on. I tried using the following code:

sed -n 'p;=' file | paste -d":" - -

However, it printed all the lines of the text file and the line number in the terminal in the following manner:

https://example.com/:1
https://example.com/:2

Answer 1

This perl one-liner does the job:

perl -i -ape 's/$/$./' inputfile

Where $ stands for end of line and $. is the current line number.