How to get words in a file which contains a single dot or period?

How to get words in a file which contains a single dot or period?

References

Reference NO 1

http://stackoverflow.com/questions/15203759/how-to-get-words-in-a-file-which-contains-a-single-dot-or-period

Reference NO 2

http://docs.oracle.com/cd/E19683-01/806-7612/filesearch-96061/index.html

Reference NO 3

http://linuxcommand.org/lts0020.php

Reference NO 4

http://www.tutorialspoint.com/python/python_quick_guide.htm

Reference NO 5

http://www.gnu.org/s/make/manual/html_node/File-Name-Functions.html

Reference NO 6

http://linuxcourse.rutgers.edu/lessons/shell_scripting/grep.php

Reference NO 7

http://www.ucblueash.edu/thomas/Intro_Unix_Text/File_System.html

Reference NO 8

http://misc.yarinareth.net/regex.html