/usr/share/postgresql/10/extension/file_fdw.control is in postgresql-10 10.3-1.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 | # file_fdw extension
comment = 'foreign-data wrapper for flat file access'
default_version = '1.0'
module_pathname = '$libdir/file_fdw'
relocatable = true
|