The prepare-svscan program

prepare-svscan does generic preparation of the supervision tree. It is also used in system-init and user-init.

Interface

     prepare-svscan workingdir rundir bundle prog...

• prepare-svscan sets its standard input to /dev/null.
• It sets the umask to 0022.
• It creates the directory rundir.
• It copies all contents of workingdir/run-image/. to rundir/.
• It changes its standard output to rundir/service/s6-svscan-log/fifo.
• prepare-svscan then forks a background process that:
  • waits for a reading end at rundir/service/s6-svscan-log/fifo.
  • Once the above is given, if rundir/s6-rc does not exist,
  • it initiates s6-rc on rundir/service using s6-rc-init and starts the bundle bundle using s6-rc.
• It copies stderr to stdout.
• If available, the directory workingdir/env is sourced using s6-env.
• prepare-svscan executest into prog..., which is usually directly or indirectly s6-svscan.

Once s6-svscan is launched it will start an s6-supervise process on rundir/service/s6-svscan-log which starts s6-log reading from rundir/service/s6-svscan-log/fifo. This in turn triggers the forked background process to continue with its second step.

Exit codes

• prepare-svscan usually executes into s6-svscan which exits according to its page.
• Since prepare-svscan is an execline script, it exits with an approximation of employed program that failed.
• prepare-svscan mostly uses execline and s6 software, the exit behaviour of which can be looked up on their respective pages.
• See also: execline exit code handling.

Options

• There are no otions to prepare-svscan.