https://blog.bekenev.net/tags/bash.html Software development related stuff en-us Wed, 31 Jan 2018 00:00:00 +0000 https://blog.bekenev.net/2018/01/31/alias-variables.html Wed, 31 Jan 2018 00:00:00 +0000 https://blog.bekenev.net/2018/01/31/alias-variables.html <p>Hey,</p> <p>Recently I had to use bash alias that contains <code>$(pwd)</code> inside so I&rsquo;ve defined it like that:</p> <div class="highlight"><pre tabindex="0" style="color:#f8f8f2;background-color:#272822;-moz-tab-size:4;-o-tab-size:4;tab-size:4;"><code class="language-bash" data-lang="bash"><span style="display:flex;"><span>alias thename<span style="color:#f92672">=</span><span style="color:#e6db74">&#34;something </span><span style="color:#66d9ef">$(</span>pwd<span style="color:#66d9ef">)</span><span style="color:#e6db74"> --option=value&#34;</span> </span></span></code></pre></div><br/> <p>Of course I know a bit of bash so that&rsquo;s why I use double quotes!</p> <center><img alt="how I feel" src="https://media.giphy.com/media/BrZTIgDc7VmnK/giphy.gif" width="200px"/></center> <p>But it turned out to be wrong. Each time when my bash/zsh was opened the alias was defined with <strong>INTERPRETED</strong> <code>$(pwd)</code> which is the directory where bash was opened (usualy home dir).</p> <p>Actually we have to use single quotes to make sure that <code>$(pwd)</code> isn&rsquo;t interpreted at the moment of alias definition but it is when we call the alias.</p> <h2 id="summary">Summary</h2> <br/> <ul> <li>use single quotes if you want to make sure variable/command is interpreted during the alias call.</li> <li>use double quotes if you only want to interpretate variable/command on the alias definition stage (and only once).</li> </ul>