https://www.enodev.fr/enTue, 16 Jan 2024 22:07:07 GMTNikola (getnikola.com)http://blogs.law.harvard.edu/tech/rsshttps://www.enodev.fr/posts/compare-binary-files.htmlChristophe Vu-Brugier<p>Diff is often used to compare two files line by line, but for binary files you must rely on other tools. My favourite tool for this task is <a href="https://www.dettus.net/dhex/">dhex</a>: I often use it to analyze data corruptions.</p> <h2>Determine if two binary files are different</h2> <p>You can compute the checksums of the two files and compare them:</p> <div class="code"><pre class="code literal-block"><span class="gp">$ </span>md5sum<span class="w"> </span>good.mp3<span class="w"> </span>bad.mp3 <span class="go">e54c63ad1efe9baea6d44a1ef836146c good.mp3</span> <span class="go">933b9d4d4323bf412ee22588db909387 bad.mp3</span> </pre></div> <p>But since you are not interested in the checksums, it is more simple to invoke <code>diff</code>:</p> <div class="code"><pre class="code literal-block"><span class="gp">$ </span>diff<span class="w"> </span>good.mp3<span class="w"> </span>bad.mp3 <span class="go">Binary files good.mp3 and bad.mp3 differ</span> </pre></div> <p>However, a better alternative is to use <code>cmp</code> because it tells you where the difference starts:</p> <div class="code"><pre class="code literal-block"><span class="gp">$ </span>cmp<span class="w"> </span>good.mp3<span class="w"> </span>bad.mp3 <span class="go">good.mp3 bad.mp3 differ: char 3527361, line 17610</span> </pre></div> <h2>View differences between binary files</h2> <p><a href="https://www.dettus.net/dhex/">dhex</a> is an hexadecimal editor but its most convenient feature in my opinion is the diff mode. To enter the diff mode, you have to invoke dhex with two files as parameters:</p> <div class="code"><pre class="code literal-block"><span class="gp">$ </span>dhex<span class="w"> </span>good.mp3<span class="w"> </span>bad.mp3 </pre></div> <p>Then to jump to the first difference, you can press F3.</p> <p><img alt="dhex showing differing bytes between two binary files" class="img-fluid" src="https://www.enodev.fr/images/dhex-corruption.png"></p>data corruptiontoolshttps://www.enodev.fr/posts/compare-binary-files.htmlSat, 05 Jul 2014 18:00:00 GMT