Linux Cheat Sheet

Print the current working directory

List files in the current directory

List all files with sizes, human-readable

Show only directories

Change to a directory

Jump to the previous directory

Change to the home directory

Show a directory structure as a tree

Print the fully resolved absolute path

Resolve file or symlink to its target path

Create an empty file or bump its mtime

Copy a file

Copy a directory recursively

Move or rename

Remove a file

Force-remove recursively (careful!)

Create nested directories

Create a symbolic link

Print the file type

Biggest directories in the tree, sorted

Full file metadata (size, perms, timestamps)

Compute an MD5 checksum

Print a file to stdout

View a file with scroll and search

Show the first 20 lines

Follow a file's new lines

Show the last 50 lines

Numbered output

Count lines in a file

Extract the first colon-delimited field

Compare two files line by line

Sort and deduplicate lines

Count consecutive duplicate lines

Find files by name pattern

Files modified more than 7 days ago

Files larger than 100 MB

Execute a command per match

Print the absolute path of a command

Locate a command (portable)

Fast filename lookup from the database

Recursive case-sensitive search

Case-insensitive search across logs

Lines starting with ERROR

Lines that do NOT match

Replace all matches in place

Print lines 10 through 20

Print the first column

Sum values in column 3

Strip carriage returns

Join lines with a comma

Run a command per input line

List all user processes

Top memory consumers

Find PIDs by command pattern

Send SIGTERM (graceful)

Force kill (SIGKILL)

Signal every process by name

Kill by full command line

Run detached from the terminal

Start a new session, fully detached

Run with low priority

Lower an existing process priority

Interactive view sorted by memory

Interactive process viewer

rwx owner, r-x group/others

rw owner, r group/others (default files)

rwx owner, r-x group, none others

Make a file executable

Recursively add group write

Change owner and group

Recursively change the owner

Change only the group

Default permissions for new files

Grant an ACL for one user

View a file's ACLs

Show Linux file attributes

Kernel and architecture details

Distro name and version

Uptime and load averages

Memory usage, human-readable

Filesystem usage by mount

Inode usage (full inodes = silent failures)

CPU model and core counts

Recent kernel messages

Hostname and OS info (systemd)

Time zone and clock sync status

Block devices and mount points

Filesystem type and UUID per partition

List mounted filesystems

Mount a device

Unmount a filesystem

Total size of a directory

List partitions on a disk

Per-device I/O stats, 2s interval

LVM layout at a glance

Current user name

UID, GID, and groups of the user

Create a user with home and shell

Add the user to a group (append)

Set or change a password

Remove a user with their home

Create a group

Switch user with their environment

Recent login sessions

Look up a user in the account database

Logs for one systemd unit

Follow a service's live logs

Logs from the last hour

This boot / previous boot

Kernel messages since boot

Errors and above only

Follow the system log

Tail the Nginx error log

Force-run log rotation

IP addresses on all interfaces

Routing table

Listening TCP ports and owner processes

Established TCP connections

Reachability and round-trip time

Local IP addresses only

Check a TCP port is open

Fetch only response headers

DNS resolver configuration (systemd)

Bring an interface up

Create a gzipped archive

Extract a gzipped archive

List contents without extracting

Extract into a specific directory

Extract without the top-level folder

Create a zip archive

Extract a zip

Synchronize with compression

Copy a file over SSH

Raw block copy (e.g. a USB stick)