locate -br '^settings.xml$'
From man locate:
locate reads one or more databases prepared by updatedb(8) and writes
file names matching at least one of the PATTERNs to standard output,
one per line.
Match only the base name against the specified patterns. This
is the opposite of --wholename.
-r, --regexp REGEXP
Search for a basic regexp REGEXP. No PATTERNs are allowed if
this option is used, but this option can be specified multiple
The ^ and $ ensure that only files whose name is settings.xml and not files whose names contain settings.xml will be printed.
You may need for the first time to run:
updatedb (as root) to update/build the database of locate.
apt-get install -y dnsutils
apt-get install -y bind-utils
$! contains the process ID of the most recently executed background pipeline.