The s6-rc-set-change program

s6-rc-set-change modifies a set by changing the sub of some services.

Interface

     s6-rc-set-change [ -v verbosity ] [ -r repo ] [ -E ] [ -f | -I fail|pull|warn ] [ -n ] set newsub services...

s6-rc-set-change operates on set set in repository repo.
It attempts to move all the services listed in services... into sub newsub.
It exits 0.

Options

-v verbosity, --verbosity=verbosity: Be more or less verbose. The default is 1, which means that error messages and warnings will be written to stderr. 0 means that only error messages will be written, and 2 or more adds informational messages.
-r repo, --repository=repo: Use the repository in repo, which must exist. Default is /var/lib/s6-rc/repository.
-E, --force-essential: This option is necessary in order if newsub is always. Without that option, s6-rc-set-change refuses to set services to always.
-f, --ignore-dependencies: Change services... to newsub, but do not change any other services, even if the dependency graph would normally mandate it. This may result in an inconsistent set that you cannot commit.

-I action, --if-dependencies-found=action

Determine what to do if a dependency would make the set inconsistent. For instance, if service A depends on service B, they are both in the latent sub, and you are trying to change A to active without mentioning B, this would not work: in order to be brought up at boot time, A would first need B to also be brought up at boot time, so A can only be active if B also is. In that situation, what s6-rc-set-change does depends on the value of action:

fail: print an error message and exit 1.
warn: print a warning message and proceed. This is the default.
pull: print a warning message and pull the dependencies of services... into newsub. (Or the reverse dependencies, if you're trying to disable or mask services.

The warning messages are not printed if verbosity is 0.

-n, --dry-run

Check whether the command would succeed, print warning or error messages if appropriate, but do not perform the actual modifications.

Exit codes

0

Success.

1

-I fail was given and dependencies prevented services... from being changed to newsub.

3

A service in services... was not found in the reference database.
4

Invalid or corrupted reference database.

100

Incorrect usage.

102

Inconsistent repository.

111

System call failed.

Notes

s6-rc-set-change is the bread and butter of repo operations. It is how users can tailor the set of services they want to be enabled at boot time.

Once a change has been effected, and the command says that the set is consistent, it needs to be committed.