167 lines
2.2 KiB
Markdown
167 lines
2.2 KiB
Markdown
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# AWK Cheat Sheet
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## Table of Contents
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1. [AWK Basics](#awk-basics)
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2. [Patterns and Actions](#patterns-and-actions)
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3. [Variables](#variables)
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4. [Operators](#operators)
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5. [Built-in Variables](#built-in-variables)
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6. [Control Structures](#control-structures)
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7. [Functions](#functions)
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8. [Text Processing](#text-processing)
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9. [Regular Expressions](#regular-expressions)
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10. [Arrays](#arrays)
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11. [User-Defined Functions](#user-defined-functions)
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12. [Command Execution](#command-execution)
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## AWK Basics
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### Print Lines
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```awk
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awk '{print}' filename
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```
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### Print Specific Column
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```awk
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awk '{print $2}' filename
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```
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### Filter with Condition
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```awk
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awk '$1 > 10 {print}' filename
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```
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## Patterns and Actions
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### Pattern with Action
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```awk
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pattern1 { action1 }
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```
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```awk
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pattern2 { action2 }
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```
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## Variables
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### Assigning Variables
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```awk
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variable = value
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```
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### Accessing Variables
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```awk
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print variable
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```
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## Operators
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### Arithmetic Operators
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```awk
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+, -, *, /, %
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```
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### Relational Operators
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```awk
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==, !=, >, <, >=, <=
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```
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### Logical Operators
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```awk
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&&, ||
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```
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## Built-in Variables
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### NR: Record Number
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```awk
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NR > 1 {print "Line Number: " NR}
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```
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### NF: Number of Fields
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```awk
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{print "Number of Fields: " NF}
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```
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## Control Structures
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### if Statement
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```awk
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if (condition) {
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# Commands
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}
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```
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### if-else Statement
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```awk
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if (condition) {
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# Commands for true condition
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} else {
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# Commands for false condition
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}
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```
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## Functions
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### Built-in Functions
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```awk
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{
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result = sqrt(9)
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print "Square Root: " result
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}
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```
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## Text Processing
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### Field Separator
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```awk
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# Change Field Separator
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awk -F',' '{print $2}' filename
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```
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### Output Formatting
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```awk
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# Formatting Output
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awk '{printf "Name: %-10s Age: %d\n", $1, $2}' filename
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```
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## Regular Expressions
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### Match Pattern
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```awk
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awk '/pattern/ {print}' filename
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```
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## Arrays
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### Declare an Array
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```awk
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array[1] = "apple"
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array[2] = "banana"
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```
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### Access Array Element
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```awk
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print array[1]
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```
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## User-Defined Functions
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### Define a Function
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```awk
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function my_function(parameter) {
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# Commands
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}
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```
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### Call the Function
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```awk
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my_function(value)
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```
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## Command Execution
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### Execute Command
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```awk
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awk '{cmd = "echo " $1; system(cmd)}' filename
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```
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