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| author | PS <p@0x53.net> | 2026-02-07 10:20:30 +0100 |
|---|---|---|
| committer | PS <p@0x53.net> | 2026-02-07 10:20:30 +0100 |
| commit | 5e95d487982b9362b544139b98d1da55fa6ef78c (patch) | |
| tree | 1abf6d91f9e6d0b6d0ac7b7d759663f2531eb51b /doc/bin/prepare-svscan.html | |
| parent | f7df2f7bb6abbea365cccb1345dcf1a1b7a80797 (diff) | |
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diff --git a/doc/bin/prepare-svscan.html b/doc/bin/prepare-svscan.html new file mode 100644 index 0000000..6b82bd5 --- /dev/null +++ b/doc/bin/prepare-svscan.html @@ -0,0 +1,120 @@ +<!DOCTYPE html> +<html> + <head> + <meta http-equiv="Content-Type" content="text/html; charset=UTF-8" /> + <meta http-equiv="Content-Language" content="en" /> + <meta name="viewport" content="width=device-width, initial-scale=1.0" /> + <title>prepare-svscan</title> + <meta name="Description" content="Helper script to initialize a supervision tree." /> + <meta name="Keywords" content="goetia s6 s6-rc supervision tree" /> + </head> + <header> + <p> + <a href="//0x53.net/software/goetia/goetia-base">goetia-base</a> + <br /> + <a href="//0x53.net/software/goetia">goetia</a> + <br /> + <a href="//0x53.net/software">Software</a> + <br /> + <a href="//0x53.net">0x53.net</a> + </p> + </header> + <body> + <h1>The prepare-svscan program</h1> + <p> + prepare-svscan does generic preparation of the + <a href="//0x53.net/software/goetia/supervisiontree.html">supervision tree</a>. + It is also used in system-init and + <a href="./user-init.html">user-init</a>. + </p> + <h2>Interface</h2> + <pre> prepare-svscan <em>workingdir</em> <em>rundir</em> <em>bundle</em> <em>prog...</em></pre> + <ul> + <li> + prepare-svscan sets its standard input to <code>/dev/null</code>. + </li> + <li> + It sets the umask to <code>0022</code>. + </li> + <li> + It creates the directory <code><em>rundir</em></code>. + </li> + <li> + It copies all contents of <code><em>workingdir</em>/run-image/.</code> + to <code><em>rundir</em>/</code>. + </li> + <li> + It changes its standard output to <code><em>rundir</em>/service/s6-svscan-log/fifo</code>. + </li> + <li> + prepare-svscan then forks a background process that: + <ul> + <li> + waits for a reading end at <code><em>rundir</em>/service/s6-svscan-log/fifo</code>. + </li> + <li> + Once the above is given, if <code><em>rundir</em>/s6-rc</code> does <em>not</em> exist, + </li> + <li> + it initiates <a href="https://skarnet.org/software/s6-rc/">s6-rc</a> on + <code><em>rundir</em>/service</code> using + <a href="https://skarnet.org/software/s6-rc/s6-rc-init.html">s6-rc-init</a> + and starts the bundle <code><em>bundle</em></code> using s6-rc. + </li> + </ul> + </li> + <li> + It copies stderr to stdout. + </li> + <li> + If available, the directory <code><em>workingdir</em>/env</code> is sourced using + <a href="https://skarnet.org/software/s6/s6-envdir.html">s6-env</a>. + </li> + <li> + prepare-svscan executest into <code><em>prog...</em></code>, + which is usually directly or indirectly + <a href="https://skarnet.org/software/s6/s6-svscan.html">s6-svscan</a>. + </li> + </ul> + <p> + Once s6-svscan is launched it will start an + <a href="https://skarnet.org/software/s6/s6-supervise.html">s6-supervise</a> + process on <code><em>rundir</em>/service/s6-svscan-log</code> which starts + <a href="https://skarnet.org/software/s6/s6-log.html">s6-log</a> reading + from <code><em>rundir</em>/service/s6-svscan-log/fifo</code>. + This in turn triggers the forked background process to continue with its second step. + </p> + <h2>Exit codes</h2> + <ul> + <li> + prepare-svscan usually executes into + <a href="https://skarnet.org/software/s6/s6-svscan.html">s6-svscan</a> + which exits according to its page. + </li> + <li> + Since prepare-svscan is an + <a href="https://skarnet.org/software/execline/">execline</a> + script, it exits with an approximation + of employed program that failed. + </li> + <li> + prepare-svscan mostly uses + <a href="https://skarnet.org/software/execline/">execline</a> + and + <a href="https://skarnet.org/software/s6/">s6</a> + software, the exit behaviour of which can be looked up on + their respective pages. + </li> + <li> + See also: + <a href="https://skarnet.org/software/execline/exitcodes.html">execline exit code handling</a>. + </li> + </ul> + <h2>Options</h2> + <ul> + <li> + There are no otions to prepare-svscan. + </li> + </ul> + </body> +</html> |