Bash Patterns and Regular Expressions

Introduction

• Use Bash to pull data in seconds
• What you should know

1. Shell Globs

• What are globs?
• Shell expansion order
• Wildcards
• Character sets
• The effect of locale on searches
• Character classes
• Shell globbing options

2. Shell Extended Globbing

• What are extended globs?
• Why you should use extended globs
• Make extended globs persistent
• Getting started with extended globs
• Pattern matching with extended globs
• Using extended globs with commands
• Comparing extended globs with regular expressions

3. Shell Brace Expansion

• What is brace expansion?
• Using brace expansion for patterns

4. Introduction to Regular Expressions

• What are regular expressions?
• Why aren't regexes consistent?
• Basic vs. Extended Regular Expressions
• Regex support in command line tools
• Matching characters and words
• Specifying occurrences
• Alternation and grouping
• Back references and subexpressions

5. Use Bash Extended Regexes

• Regexes in if conditionals
• Using BASH_REMATCH
• Challenge: Regex to find credit card numbers
• Solution: Regex to find credit card numbers

6. Grep EREs and PCREs

• Using regular expressions with grep
• Perl compatible regexes with grep
• Performance optimizing grep searches
• Challenge: Create a regex to find telephone numbers
• Solution: Create a regex to find telephone numbers

7. Use sed Regexes

• Using sed
• Using extended regexes in sed
• Challenge: Create a regex to find IPv4 addresses
• Solution: Create a regex to find IPv4 addresses

8. Use AWK Extended Regexes

• Using regexes in AWK
• Pattern matching differences in AWK

Conclusion

• Next steps