How to write the filename on top-left corner of each page of documentclass article

Question

How to add the document's filename at the top left corner of each page in the following minimum working example:

\documentclass{article}
\begin{document}
    % \markboth{\jobname}{\jobname}
    Hello!
    \clearpage
    This is the second page.
\end{document}

I have tried \markboth{\jobname}{\jobname} just after \begin{document} but in vain.

Answer 1

Your code is fine. You just need to switch from the default page style of the article document class (plain) to a page style that allows for a non-empty header line. LaTeX provides the myheadings page styles for your purpose. (The page style headings might work as well -- but only if the document doesn't contain any section-level headers.)

\documentclass{article}
\pagestyle{myheadings}
\begin{document}
    \markboth{\jobname}{\jobname}
    Hello!
    \clearpage
    This is the second page.
\end{document}

Answer 2

For example with the fancyhdr package:

\documentclass{article}

\usepackage{fancyhdr}
\pagestyle{fancy}

\begin{document}
    \markboth{}{\jobname}
    Hello!
    \clearpage
    This is the second page.
\end{document}