How to configure Access Control Lists (ACLs) on Linux - Linux FAQ

reference

http://xmodulo.com/2014/08/configure-access-control-lists-acls-linux.html

Tools - Cool Infographics

http://www.coolinfographics.com/tools/

Introduction to dplyr

http://cran.rstudio.com/web/packages/dplyr/vignettes/introduction.html

Ultimate Sed - An Introduction and Tutorial

http://www.grymoire.com/unix/sed.html

30 Python Language Features and Tricks You May Not Know About

http://sahandsaba.com/thirty-python-language-features-and-tricks-you-may-not-know.html

the Invisible Man is in your spreadsheet, messing with your data | School of Data - Evidence is Power

http://schoolofdata.org/handbook/courses/data-cleaning-invisible-man-in-spreadsheets/

Easy and clean - Regular Expressions

http://qntm.org/files/re/re.html