https://scripter.co/categories/makefile/Recent content in makefile on A Scripter's Notesen-uskaushal.modi@gmail.com (Kaushal Modi)kaushal.modi@gmail.com (Kaushal Modi)Wed, 22 Apr 2026 08:24:58 -0400Hugo -- gohugo.iohttps://validator.w3.org/feed/docs/rss2.htmlhttps://scripter.co/how-to-do-math-in-makefile/<p>If you have <code>bc</code> installed, you can use it to do math operations on variables in a <em>Makefile</em>.</p> <p>For me, it was installed in <code>/usr/bin/bc</code>.</p> <div class="highlight"><pre tabindex="0" class="chroma"><code class="language-makefile" data-lang="makefile"><span class="line"><span class="cl"><span class="nv">VAR_A</span> <span class="o">=</span> <span class="m">10</span> </span></span><span class="line"><span class="cl"><span class="nv">VAR_B</span> <span class="o">=</span> <span class="m">11</span> </span></span><span class="line"><span class="cl"><span class="nv">VAR_C</span> <span class="o">=</span> <span class="k">$(</span>shell <span class="nb">echo</span> <span class="k">$(</span>VAR_A<span class="k">)</span><span class="se">\*</span><span class="k">$(</span>VAR_B<span class="k">)</span> <span class="p">|</span> bc<span class="k">)</span> </span></span><span class="line"><span class="cl"> </span></span><span class="line"><span class="cl"><span class="nf">default</span><span class="o">:</span> </span></span><span class="line"><span class="cl"> <span class="nb">echo</span> <span class="k">$(</span>VAR_C<span class="k">)</span> </span></span></code></pre></div>makefilebchttps://scripter.co/how-to-do-math-in-makefile/Wed, 05 Mar 2014 13:38:08 -0500