Regarding adduser -S
and addgroup -S
described at https://busybox.net/downloads/BusyBox.html
What is the difference between creating a 'system user' and a non-system user? I cannot find additional information about this configuration. When might I choose to create a system user over a non-system user?
I see the same option applies to creating user groups.
I can look at regular Linux man pages like https://www.systutorials.com/docs/linux/man/8-useradd/ to get the concept, but I'm still unsure if the busybox implementation is exactly the same, or if there is additional busybox information available that I should be aware of when using the command. For example, the parameter names differ in the busybox implementation vs standard man page link provided in this question, which gives me pause.
AFAIK a system user gets a UID number with a value in the reserved range (100-500) rather then the first available UID number for regular accounts.
The actual ranges for both system user UID numbers as well as those for "regular" users are defined in
/etc/login.defs