user-init

The user-init program

user-init starts a user supervision tree for the user defined in the USER environment variable.

Interface

     user-init

user-init takes no arguments.
It reads the USER environment variable, if it is empty it exits 100.
It reads the USERTREE environment variable, if it is empty it exits 100.
It reads the BUNDLE environment variable, defaulting to default if empty.
It reads the PATH environment variable, defaulting to /command:/sbin:/bin:/usr/sbin:/usr/bin:/usr/local/sbin:/usr/local/bin:/usr/libexec:/usr/local/libexec if empty.
if ${USER}/${USERTREE} subdirectory of the runtime directory olready existis, it exits 100.
It sets the HOME environment variable based on the result of homeof.
It prepends ${HOME}/.local/bin: to the PATH environment variable.
It sets the UID, GID and GIDLIST environment variables using s6-envuidgid.
It runs prepare-svscan with the proper arguments.
Finally, it executes into s6-svscan on the scandir represented by the ${USER}/${USERTREE}/service subdirectory of the user runtime directory.

100 if a critical environment variable is missing.
user-init usually executes into s6-svscan which exits according to its documentation.
Since user-init is an execline script, it exits with an approximation of employed program that failed.
user-init mostly uses execline and s6 software, the exit behaviour of which can be looked up on their respective documentation.
See also: execline exit code handling.

More information about user supervision trees themselves can be found on the user supervision tree page.