As I understand, in Linux /bin/sh(points to /bin/dash in some distributions) is the default system shell. Does it run (SysV) init scripts? Anything else? Any why isn't root user shell(/bin/bash in Debian according to /etc/passwd) used for those tasks? The reason I ask is that I read the LPIC-1 study guide and it said that:The default system shell is used by the Linux system to run system shell scripts, typically at startup.I had an impression that startup happens under root user and thus root user shell is used.
What are the responsibilities of the default system shell?
shell;startup
You would want these scripts to not depend on the default shell of any user, including root. If the admin changed the default shell of root, it should not affect the system in any unexpected way, including startup.This is true of all scripts, and is why all scripts should start with #! to specify what interpreter to use.