LINUX CHEATSHEET
Updated: 31 October 2026

Replace uppercase placeholders with your values. Linux examples use a Linux shell; they are not PowerShell commands.

NAVIGATE DIRECTORIES

# Show your current directory [View]
pwd

# List files [View]
ls

# Include details and hidden files [View]
ls -lah

# Enter a directory [Change]
cd /PATH/TO/DIRECTORY

# Go up one directory [Change]
cd ..

# Go to your home directory [Change]
cd ~

CREATE, COPY & MOVE FILES

# Create a directory [Change]
mkdir DIRECTORY

# Create nested directories [Change]
mkdir -p PATH/TO/DIRECTORY
# Creates missing parent directories too.

# Create an empty file [Change]
touch FILE
# If the file exists, updates timestamps without clearing its content.

# Copy a file [Change]
cp -i SOURCE DESTINATION
# Prompts before overwriting an existing destination.

# Move or rename a file [Change]
mv -i SOURCE DESTINATION
# Prompts before overwriting an existing destination.

READ FILES & LOGS

# Print a file [View]
cat FILE

# Read a file one screen at a time [View]
less FILE
# Press q to quit; / searches within the file.

# Read the first 30 lines [View]
head -n 30 FILE

# Read the last 50 lines [View]
tail -n 50 FILE

# Follow a rotating log [View]
tail -F FILE
# Retries when the file is replaced. Stop with Ctrl+C.

SEARCH FILES & TEXT

# Find files by name [View]
find . -type f -name "*.log"
# Searches under the current directory. Keep the pattern quoted.

# Search with line numbers [View]
grep -n -- "PATTERN" FILE
# PATTERN is a regular expression.

# Search for literal text [View]
grep -Fn -- "TEXT" FILE
# Treats the search text as literal characters.

# Count lines [View]
wc -l FILE

IDENTITY & PERMISSIONS

# Show your username [View]
whoami

# Show your identity and groups [View]
id

# Inspect file permissions [View]
ls -l FILE

# Show detailed file information [View]
stat FILE

# Make a file private to its owner [Change]
chmod 600 FILE
# Owner can read and write; group and others have no access. Does not change ownership.

# Make a script executable by its owner [Change]
chmod u+x SCRIPT.sh

STORAGE & PROCESSES

# Show filesystem free space [View]
df -h

# Show a directory size [View]
du -sh DIRECTORY
# Permission errors may mean some paths were not counted.

# List processes [View]
ps -ef

# Request a process to stop [Change]
kill -TERM PID
# Verify the process ID first. Sends a termination signal.

REMOVE FILES & DIRECTORIES

# Remove an empty directory [Delete]
rmdir DIRECTORY
# Only succeeds if the directory is empty.

# Remove a file with confirmation [Delete]
rm -i -- FILE
# Permanently deletes the named file after a prompt; does not move it to trash.

GET COMMAND HELP

# Read a command manual [View]
man COMMAND
# For example: man ls. Press q to quit.

# Show built-in shell help [View]
help cd
# For Bash shell built-ins.

PIPELINES AND STRUCTURED TEXT

# Count lines, words, and bytes [View]
wc -l -w -c FILE

# Sort numbers numerically [View]
sort -n FILE

# Count repeated sorted lines [View]
sort FILE | uniq -c

# Extract a delimited field [View]
cut -d: -f2 FILE
# Selects the second colon-separated field.

# Print a whitespace-separated field [View]
awk '{print $1}' FILE

# Match only the start of a line [View]
grep -n '^ERROR ' FILE

# Select lines that do not match [View]
grep -v 'PATTERN' FILE

# Preview an exact-line replacement [View]
sed 's/^OLD$/NEW/' FILE
# Prints the result without changing FILE.

# Replace an exact line in place [Change]
sed -i 's/^OLD$/NEW/' FILE
# Linux sed example; overwrites the matched lines. Review or back up important files first.

# Write output to screen and a file [Change]
COMMAND | tee output.txt
# Overwrites output.txt; tee -a appends.

LINKS AND FILE METADATA

# Create a relative symbolic link [Change]
ln -s TARGET LINK_NAME
# The target path is interpreted from the link’s directory.

# Read a link target [View]
readlink LINK_NAME

# Inspect a file mode and owner [View]
stat FILE

# Create private files by default [Change]
umask 077
# Applies to subsequently created files in this shell.

# Find log files safely [View]
find . -type f -name '*.log'

# Pass filenames using null separators [View]
find . -type f -name '*.log' -print0 | xargs -0 wc -l
# Avoids splitting paths containing spaces.

# Show hidden files with details [View]
ls -la

# Identify file content type [View]
file FILE
# Requires the file utility.

COMPARE, ARCHIVE, AND VERIFY

# Show a unified diff [View]
diff -u BEFORE AFTER
# Exit 1 means differences; greater than 1 means an error.

# Compare bytes without printing contents [View]
cmp FIRST SECOND
# Exit 0 means identical; 1 means different.

# Record a checksum [Change]
sha256sum FILE > FILE.sha256
# Writes a digest and filename into a new checksum file.

# Check a recorded checksum [View]
sha256sum -c FILE.sha256

# List a compressed tar archive [View]
tar -tzf ARCHIVE.tar.gz

# Create a compressed archive [Change]
tar -czf ARCHIVE.tar.gz DIRECTORY
# Creates or replaces the named archive.

# Extract into a chosen directory [Change]
tar -xzf ARCHIVE.tar.gz -C DESTINATION
# Inspect untrusted archive paths and use a dedicated destination.

PROCESSES AND SERVICES

# List processes [View]
ps -ef

# Inspect one process [View]
ps -p PID -o pid,ppid,comm

# Request a specific process to stop [Change]
kill -TERM PID
# Check the PID and owner first; this can stop running work.

# Inspect listening TCP sockets [View]
ss -lnt
# Linux iproute2 utility; package availability varies.

# Show interface addresses [View]
ip address show
# Linux iproute2 utility.

# Read recent service logs [View]
journalctl -u SERVICE -n 100 --no-pager
# Requires systemd journal access.

# Inspect a service without changing it [View]
systemctl status SERVICE --no-pager
# Requires a systemd-based environment.