Merge pull request #1310 from kingdido999/master

added [The 30 Minute Regex Tutorial] to [Regular Expressions]

free-programming-books.md

@@ -522,6 +522,7 @@ Original Source: [Free Programming books](http://stackoverflow.com/revisions/392
 #### Regular Expressions
 * [Learn Regex The Hard Way](http://regex.learncodethehardway.org/book/) - Zed. A. Shaw
 * [The Bastards Book of Regular Expressions: Finding Patterns in Everyday Text](https://leanpub.com/bastards-regexes) - Dan Nguyen
+* [The 30 Minute Regex Tutorial](http://www.codeproject.com/Articles/9099/The-Minute-Regex-Tutorial) - Jim Hollenhorst
 
 
 #### Reverse Engineering
@@ -1799,6 +1800,7 @@ See also [LaTeX](#latex)
 * [Unix Toolbox](http://cb.vu/unixtoolbox.xhtml) - Colin Barschel
 * [UNIX Tutorial for Beginners](http://www.ee.surrey.ac.uk/Teaching/Unix/)
 * [Unix for Poets](http://www.stanford.edu/class/cs124/kwc-unix-for-poets.pdf) - Kenneth Ward Church (PDF)
+* [UNIX Commands and Concepts](http://www.cs.bu.edu/teaching/unix/reference/) - Robert I. Pitts
 
 
 ### Verilog