<p dir="auto">it always opens as utf8 ,  can i set auto-detect as default ？</p>
<p dir="auto">Atom should try to guess the encoding when opening a file as best as it can and only if it fails, fallback to the default encoding option (which was implemented a few days ago).</p>
<p dir="auto">Missing libraries (that would presumably help with this issue) shouldn't be a factor here. If there isn't any library that could be used, one should be created from 0 or maybe patch the one that could get the job done with as little amount of work as possible.</p>
<p dir="auto">The main issue here is that Atom will try to open files in UTF8 (or the default encoding, if set), which will potentially break any non-UTF8 files. And that, imho, is not an acceptable/valid behavior for any editor.</p>
<p dir="auto">This should be tagged as 1.0 blocker.</p>
<p dir="auto">Also, maybe this could help:</p>
<ul dir="auto">
<li><a href="https://github.com/mooz/node-icu-charset-detector">https://github.com/mooz/node-icu-charset-detector</a></li>
<li><a href="https://www.npmjs.org/package/detect-encoding" rel="nofollow">https://www.npmjs.org/package/detect-encoding</a></li>
</ul>