$devvkit resources --cheatsheet linux-command-line

Linux Command Line

[terminal]

Essential Linux shell commands for file operations, navigation, permissions, processes, and text processing.

The Linux command line is the most powerful interface for development and operations work. This cheatsheet covers navigation, file operations, permissions, process management, and text processing with pipes.

Commands are written for bash/zsh and should work on any Unix-like system including macOS and WSL.

Navigation & File Info

$pwd

Print the current working directory path.Example: pwd # /home/user/projects

$ls -la

List all files and directories with details — permissions, size, owner, modified time.Example: ls -la

$cd <dir>

Change to the specified directory.Example: cd /var/log

$cd ~

Change to the home directory.Example: cd ~

$cd -

Change to the previous directory (back and forth toggle).Example: cd -

$tree -L 2

Display directory structure as a tree, 2 levels deep.Example: tree -L 2

$du -sh <dir>

Show total disk usage of a directory in human-readable format.Example: du -sh ./node_modules

File Operations

$cp <src> <dest>

Copy a file or directory (use -r for directories).Example: cp -r ./src ./backup

$mv <src> <dest>

Move or rename a file or directory.Example: mv old-name.txt new-name.txt

$rm <file>

Delete a file permanently. Use -r for directories, -f to force.Example: rm -rf ./node_modules

$mkdir -p <path>

Create a directory, including any necessary parent directories.Example: mkdir -p src/components/ui

$touch <file>

Create an empty file or update the timestamp of an existing file.Example: touch README.md

$ln -s <target> <link>

Create a symbolic (soft) link pointing to a file or directory.Example: ln -s /usr/local/bin/node ./node

Permissions & Ownership

$chmod 755 <file>

Set file permissions — owner: rwx, group: rx, others: rx.Example: chmod +x deploy.sh

$chown <user>:<group> <file>

Change the owner and group of a file or directory.Example: chown -R www-data:www-data /var/www

Process Management

$ps aux

List all running processes with detailed info (user, PID, CPU, memory).Example: ps aux | grep node

$top

Interactive real-time view of running processes and system resource usage.Example: top

$kill <PID>

Send SIGTERM to a process by PID, asking it to terminate gracefully.Example: kill 1234

$kill -9 <PID>

Force kill a process with SIGKILL. Use only if SIGTERM fails.Example: kill -9 1234

$nohup <cmd> &

Run a command immune to hangups, in the background.Example: nohup python server.py &

Text Processing & Pipes

$cat <file>

Output the full contents of a file to stdout.Example: cat package.json

$less <file>

View file contents with interactive scrolling and search (/ to search).Example: less large-log-file.log

$head -n 20 <file>

Print the first 20 lines of a file.Example: head -n 20 server.log

$tail -n 20 -f <file>

Print the last 20 lines and follow new output as it grows.Example: tail -n 100 -f /var/log/syslog

$grep -r "pattern" <dir>

Recursively search for a pattern in files within a directory.Example: grep -rn "TODO" ./src

$grep -v "exclude" <file>

Invert the match — show lines that do NOT contain the pattern.Example: grep -v "DEBUG" app.log

$sed -i "s/old/new/g" <file>

Replace all occurrences of old with new in-place using regex.Example: sed -i 's/foo/bar/g' config.js

$awk '{print $1}' <file>

Print the first column of each line (space-delimited by default).Example: awk '{print $2, $1}' data.txt

$sort <file> | uniq -c

Sort lines and then count unique occurrences.Example: sort words.txt | uniq -c | sort -rn

$wc -l <file>

Count lines, words, and characters in a file.Example: wc -l src/*.ts

Archives & Disk

$tar -czvf archive.tar.gz <dir>

Create a compressed tarball archive.Example: tar -czvf backup.tar.gz ./project

$tar -xzvf archive.tar.gz

Extract a compressed tarball archive.Example: tar -xzvf backup.tar.gz

$zip -r archive.zip <dir>

Create a compressed zip archive.Example: zip -r project.zip ./src

$df -h

Show disk space usage for all mounted filesystems in human-readable format.Example: df -h

$free -h

Display system memory usage (RAM + swap) in human-readable format.Example: free -h

Linux Command Line

Essential Linux shell commands for file operations, navigation, permissions, processes, and text processing.

Commands are written for bash/zsh and should work on any Unix-like system including macOS and WSL.

Navigation & File Info

pwd — Print the current working directory path.

Example: pwd # /home/user/projects

ls -la — List all files and directories with details — permissions, size, owner, modified time.

Example: ls -la

cd <dir> — Change to the specified directory.

Example: cd /var/log

cd ~ — Change to the home directory.

Example: cd ~

cd - — Change to the previous directory (back and forth toggle).

Example: cd -

tree -L 2 — Display directory structure as a tree, 2 levels deep.

Example: tree -L 2

du -sh <dir> — Show total disk usage of a directory in human-readable format.

Example: du -sh ./node_modules

File Operations

cp <src> <dest> — Copy a file or directory (use -r for directories).

Example: cp -r ./src ./backup

mv <src> <dest> — Move or rename a file or directory.

Example: mv old-name.txt new-name.txt

rm <file> — Delete a file permanently. Use -r for directories, -f to force.

Example: rm -rf ./node_modules

mkdir -p <path> — Create a directory, including any necessary parent directories.

Example: mkdir -p src/components/ui

touch <file> — Create an empty file or update the timestamp of an existing file.

Example: touch README.md

ln -s <target> <link> — Create a symbolic (soft) link pointing to a file or directory.

Example: ln -s /usr/local/bin/node ./node

Permissions & Ownership

chmod 755 <file> — Set file permissions — owner: rwx, group: rx, others: rx.

Example: chmod +x deploy.sh

chown <user>:<group> <file> — Change the owner and group of a file or directory.

Example: chown -R www-data:www-data /var/www

Process Management

ps aux — List all running processes with detailed info (user, PID, CPU, memory).

Example: ps aux | grep node

top — Interactive real-time view of running processes and system resource usage.

Example: top

kill <PID> — Send SIGTERM to a process by PID, asking it to terminate gracefully.

Example: kill 1234

kill -9 <PID> — Force kill a process with SIGKILL. Use only if SIGTERM fails.

Example: kill -9 1234

nohup <cmd> & — Run a command immune to hangups, in the background.

Example: nohup python server.py &

Text Processing & Pipes

cat <file> — Output the full contents of a file to stdout.

Example: cat package.json

less <file> — View file contents with interactive scrolling and search (/ to search).

Example: less large-log-file.log

head -n 20 <file> — Print the first 20 lines of a file.

Example: head -n 20 server.log

tail -n 20 -f <file> — Print the last 20 lines and follow new output as it grows.

Example: tail -n 100 -f /var/log/syslog

grep -r "pattern" <dir> — Recursively search for a pattern in files within a directory.

Example: grep -rn "TODO" ./src

grep -v "exclude" <file> — Invert the match — show lines that do NOT contain the pattern.

Example: grep -v "DEBUG" app.log

sed -i "s/old/new/g" <file> — Replace all occurrences of old with new in-place using regex.

Example: sed -i 's/foo/bar/g' config.js

awk '{print $1}' <file> — Print the first column of each line (space-delimited by default).

Example: awk '{print $2, $1}' data.txt

sort <file> | uniq -c — Sort lines and then count unique occurrences.

Example: sort words.txt | uniq -c | sort -rn

wc -l <file> — Count lines, words, and characters in a file.

Example: wc -l src/*.ts

Archives & Disk

tar -czvf archive.tar.gz <dir> — Create a compressed tarball archive.

Example: tar -czvf backup.tar.gz ./project

tar -xzvf archive.tar.gz — Extract a compressed tarball archive.

Example: tar -xzvf backup.tar.gz

zip -r archive.zip <dir> — Create a compressed zip archive.

Example: zip -r project.zip ./src

df -h — Show disk space usage for all mounted filesystems in human-readable format.

Example: df -h

free -h — Display system memory usage (RAM + swap) in human-readable format.

Example: free -h