Line numbers for 2 columns on the sides

Question

How am I supposed to put line numbers in 2 columns, on the left side for the left one and on the right side for the right one?

I've read a pdf there's on internet but there's nothing, I've tried already with the next commands, but no one works, the line numbers appear always in the left or in the right side, but not both in a single page:

\documentclass[twocolumn]{article}
\usepackage[columnwise]{lineno}
\usepackage[switch]{lineno} 
\usepackage[switch,columnwise]{lineno}

Answer 1

Assuming you're using a not-too-funky document class, i.e., one which implements the twocolumn option in a reasonably robust way, setting the option switch while loading lineno should achieve exactly what you say you need to achieve.

Do note that the lineno package does not recognize an option called columnwise. You should have been getting error messages when running either \usepackage[columnwise]{lineno} or \usepackage[switch,columnwise]{lineno}.

Here's an example. Note that the IEEEtran class employs twocolumn mode by default.

\documentclass{IEEEtran} % or any other document class that uses 'twocolumn' mode
\usepackage[switch]{lineno} % default option is 'left'
\usepackage{lipsum} % filler text

\begin{document}
\linenumbers
\lipsum[1-20]
\end{document}