Software
skarnet.org

s6-linux-utils

What is it ?

s6-linux-utils is a set of minimalistic Linux-specific system utilities.

Prefixing the name of this package — and the names of the binaries it provides — with s6- was a naming mistake. It happened in the early days of the s6 project, before it grew and became an ecosystem focused on supervision, service management and init; despite sharing the same author and the same philosophy, and being designed to work with it, s6-linux-utils is not, stricto sensu, part of the s6 ecosystem, and if you arrived here while trying to understand what s6 is, you are on the wrong page. I apologize for the confusion.

Installation

Requirements

• A Linux-based system with a standard C development environment. The Linux kernel must be 3.5 or later.
• GNU make, version 3.81 or later
• skalibs version 2.14.4.0 or later. It's a build-time requirement. It's also a run-time requirement if you link against the shared version of the skalibs library.

Licensing

s6-linux-utils is free software. It is available under the ISC license.

Download

• The current released version of s6-linux-utils is 2.6.3.0. You can access its checksum here.
• Alternatively, you can checkout a copy of the s6-linux-utils git repository:

   git clone git://git.skarnet.org/s6-linux-utils 

• There's also a GitHub mirror of the s6-linux-utils git repository.

Compilation

• See the enclosed INSTALL file for installation details.
• Starting with version 2.6.1.0, you can use the --enable-multicall configure option to save disk space.

Upgrade notes

• This page lists the differences to be aware of between the previous versions of s6-linux-utils and the current one.

Reference

Commands

All these commands exit 111 if they encounter a temporary error, and 100 if they encounter a permanent error - such as a misuse. They exit 127 if they're trying to execute into a program and cannot find it, and 126 if they fail to execute into a program for another reason.

(Miscellaneous tools)

• The rngseed program
• The s6-chroot program
• The s6-freeramdisk program
• The s6-hostname program
• The s6-logwatch program
• The s6-mount program
• The s6-pivotchroot program
• The s6-ps program
• The s6-swapoff program
• The s6-swapon program
• The s6-umount program

(Multicall configuration)

• The s6-linux-utils multicall binary

Related resources

• s6-linux-utils is discussed on the skaware mailing-list.

Similar work

There are several good projects aiming to provide a minimal userspace environment for Linux, suitable for embedded systems. Among them, for instance:

• BusyBox
• toybox
• sbase and ubase

Most of the time, these projects aim to implement standard commands in a lightweight way, and they do it well enough. So, although some standard reimplentation already exists in s6-linux-utils and its sibling package s6-portable-utils, it is an explicit non-goal of those packages to duplicate the work of those projects, and no more rewriting of standard commands will occur.