awk

• Getting started with awk
• Arrays
• Built-in functions
• Built-in Variables
• Fields
• Patterns
• Patterns and Actions
• Row Manipulation
• Extract specific column/field from specific line
• Extract specific lines from a text file
• Modifying rows on-the-fly (e.g. to fix Windows line-endings)
• String manipulation functions
• Two-file processing
• Useful one-liners - calculating average from a CSV etc
• Variables