Regular expressions Tutorial For Linux

#linux #bash #regex #beginners

In order to successfully work with the Linux sed editor and the awk command in your shell scripts, you have to understand regular expressions or in short regex. Since there are many engines for regex, we will use the shell regex and see the bash power in working with regex.

First, we need to understand what regex is, then we will see how to use it.

1 What is regex
2 Types of regex
3 Define BRE Patterns
4 Special Characters
5 Anchor Characters
6 The dot Character
7 Character Classes
8 Negating Character Classes
9 Using Ranges
10 Special Character Classes
11 The Asterisk
12 Extended Regular Expressions
12.1 The question mark
12.2 The Plus Sign
12.3 Curly Braces
12.4 Pipe Symbol
13 Grouping Expressions
14 Practical examples
14.1 Counting Directory Files
14.2 Validating E-mail Address