https://hashbang.ca/tag/prepan Recent content in Prepan on Hashbang.ca Hugo en-us Sat, 26 May 2012 00:39:00 -0400 https://hashbang.ca/post/introducing-filesymlinkatomic Sat, 26 May 2012 00:39:00 -0400 https://hashbang.ca/post/introducing-filesymlinkatomic/ <p>In <a href="https://hashbang.ca/post/tips-tricks-from-my-4-months-at-pythian">Tips &amp; tricks from my 4 months at Pythian</a>, I showed how to give a symlink a new target atomically. I wasn&rsquo;t aware of any module to encapsulate that, so I quickly put together <code>File::Symlink::Atomic</code>.</p> <p>This module is useful because it eliminates the need to know how to do this safely - simply <code>use File::Symlink::Atomic</code> and you get a drop-in replacement for <code>CORE::symlink</code>. It creates a temporary symlink (using <code>File::Temp</code> to get a unique pathname) pointing to your new target, then moves it into place with a <code>rename</code> call. On POSIX systems, the rename system call <a href="http://pubs.opengroup.org/onlinepubs/9699919799/functions/rename.html">guarantees atomicity</a>.</p>