Q:

How would I do this in a unix system?

I need to locate all of the file system objects below the /sbin directory that include a period (.) somewhere in the object’s name, but not objects that begin with a leading period. 

A:

Try this in your /sbin folder
Find *.txt file but ignore hidden .txt file such as .vimrc or .data.txt file:
$ find . -type f \( -iname "*.txt" ! -iname ".*" \)

The -type f option forces to only search files and not directories.

