diff options
| author | Laurent Bercot <ska-skaware@skarnet.org> | 2015-02-23 23:28:58 +0000 |
|---|---|---|
| committer | Laurent Bercot <ska-skaware@skarnet.org> | 2015-02-23 23:28:58 +0000 |
| commit | fe1f70d5f729e331facf481ec45cc1c64e095d85 (patch) | |
| tree | 54ecbfa97635cf15f1e7b1cbd8eae33939ad1747 /doc/s6-hiercopy.html | |
| parent | 1a193920ece5297d8676afef5b1e69e785522ad3 (diff) | |
| download | s6-portable-utils-2.0.2.0.tar.xz | |
Add s6-hiercopy (based on skalibs)v2.0.2.0
Version: rc for 2.0.2.0
Diffstat (limited to 'doc/s6-hiercopy.html')
| -rw-r--r-- | doc/s6-hiercopy.html | 66 |
1 files changed, 66 insertions, 0 deletions
diff --git a/doc/s6-hiercopy.html b/doc/s6-hiercopy.html new file mode 100644 index 0000000..a4c12f0 --- /dev/null +++ b/doc/s6-hiercopy.html @@ -0,0 +1,66 @@ +<html> + <head> + <meta http-equiv="Content-Type" content="text/html; charset=UTF-8" /> + <meta http-equiv="Content-Language" content="en" /> + <title>s6-portable-utils: the s6-hiercopy program</title> + <meta name="Description" content="s6-portable-utils: the s6-hiercopy program" /> + <meta name="Keywords" content="s6 linux administration root utilities hiercopy cp -a" /> + <!-- <link rel="stylesheet" type="text/css" href="http://skarnet.org/default.css" /> --> + </head> +<body> + +<p> +<a href="index.html">s6-portable-utils</a><br /> +<a href="http://skarnet.org/software/">Software</a><br /> +<a href="http://skarnet.org/">skarnet.org</a> +</p> + +<h1> The <tt>s6-hiercopy</tt> program </h1> + +<p> +<tt>s6-hiercopy</tt> copies a directory structure recursively. +</p> + +<h2> Interface </h2> + +<pre> + s6-hiercopy <em>source</em> <em>destination</em> +</pre> + +<ul> + <li> <tt>s6-hiercopy</tt> recursively copies <em>source</em> to +<em>destination</em>, which is created if it doesn't exist. +The permissions are preserved. The owner and group are preserved +if the user is the superuser. </li> + <li> It exits 0 on success and 111 on temporary failure. </li> +</ul> + +<h2> Notes </h2> + +<ul> + <li> Copying files and browsing through directories is one of Unix's +weakest points, and <tt>s6-hiercopy</tt> is not meant to work around +the problem; it's only a quick hack that I needed to boot my embedded +platform. I originally planned to write the ultimate <tt>cp</tt> utility, +portable and reliable and featureful and everything - while needing +approximately a hundred times less resources than GNU <tt>cp</tt> does, +of course. But I eventually dropped the idea: it's impossible to +design, much less write, such a utility. Notably, + you cannot make it reliable because Unix's set of filesystem +management primitives is just too weak. It lacks a lot of atomic +operations, and filesystem transactions. As a result, <tt>s6-hiercopy</tt> +is a walking race condition and should <strong>absolutely not</strong> +be considered instant when used in a multitasking environment. +But then, <tt>cp</tt> shouldn't either. </li> + <li> There is no standard way of creating device nodes on a +filesystem, so any <tt>cp</tt>-like utility is inherently +non-portable. Fortunately, most systems still agree on the non-portable usages of +<a href="http://pubs.opengroup.org/onlinepubs/9699919799/functions/mknod.html">mknod +specification</a>, so things should work in practice. Consequently, +the s6-hiercopy utility has been moved from +<a href="http://skarnet.org/software/s6-linux-utils/">s6-linux-utils</a> +to s6-portable-utils. </li> +</ul> + +</body> +</html> |