bash-linux

Bash Linux Patterns

Essential patterns for Bash on Linux/macOS.

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1. Operator Syntax

Chaining Commands

Operator	Meaning	Example
;	Run sequentially	cmd1; cmd2
&&	Run if previous succeeded	npm install && npm run dev
`\	\	`	Run if previous failed	`npm test \	\	echo "Tests failed"`
`\	`	Pipe output	`ls \	grep ".js"`

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2. File Operations

Essential Commands

Task	Command
List all	ls -la
Find files	find . -name "*.js" -type f
File content	cat file.txt
First N lines	head -n 20 file.txt
Last N lines	tail -n 20 file.txt
Follow log	tail -f log.txt
Search in files	grep -r "pattern" --include="*.js"
File size	du -sh *
Disk usage	df -h

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3. Process Management

Task	Command
List processes	ps aux
Find by name	`ps aux \	grep node`
Kill by PID	kill -9 <PID>
Find port user	lsof -i :3000
Kill port	kill -9 $(lsof -t -i :3000)
Background	npm run dev &
Jobs	jobs -l
Bring to front	fg %1

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4. Text Processing

Core Tools

Tool	Purpose	Example
grep	Search	grep -rn "TODO" src/
sed	Replace	sed -i 's/old/new/g' file.txt
awk	Extrac