Improve ripgrep examples

24_finding_files/README.md

@@ -79,6 +79,8 @@ locate  "/etc/*.conf"
 
 ## exa
 
+exa is a modern replacement for the venerable file-listing command-line program ls that ships with Unix and Linux operating systems, giving it more features and better defaults.  
+
 ```sh
 brew install exa
 
@@ -88,6 +90,8 @@ exa -laTR --icons --git | grep ".*\.md"
 
 ## fd
 
+fd is a program to find entries in your filesystem. It is a simple, fast and user-friendly alternative to find.  
+
 ```sh
 brew install fd
 
@@ -100,17 +104,18 @@ fd -e md
 
 ## ripgrep
 
+ripgrep is a line-oriented search tool that recursively searches the current directory for a regex pattern.  
+
 ```sh
 brew install ripgrep
 
 # find all files containing README
-rg README
+rg --ignore-case README
 
 # searching in node_modules (including .gitignore) 
 rg --no-ignore --hidden "items to be sent"
 ```
 
-
 ## Resources
 
 * ogham/exa repo [here](https://github.com/ogham/exa)  

51_grep_and_regex/README.md

@@ -2,7 +2,10 @@
 
 Demonstrates examples of how to use grep and regex.  
 
+REF: ripgrep in [24_finding_files/README.md](../24_finding_files/README.md)  
+
 ```sh
+# MacOS grep (BSD grep, GNU compatible) 2.6.0-FreeBSD
 grep --version    
 ```
 
@@ -16,6 +19,9 @@ brew install grep
 
 # can now use ggrep
 ggrep
+
+# ggrep (GNU grep) 3.7
+ggrep --version
 ```
 
 ## Common uses