Linux commands reference
Common commands and flag combinations you actually use.
ls -la
List all files, including hidden, in long format.
cd /path/to/dir
Change directory.
pwd
Print the current working directory.
cp -r src dest
Copy files/directories recursively.
mv src dest
Move or rename a file/directory.
rm -rf dir
Remove a directory and its contents, forcefully.
mkdir -p a/b/c
Create nested directories, no error if they exist.
find . -name "*.log"
Find files by name pattern under the current directory.
grep -r "pattern" .
Search recursively for a text pattern.
chmod 755 file
Set permissions: owner rwx, group/others r-x.
chown user:group file
Change file owner and group.
tar -czvf out.tar.gz dir
Create a gzip-compressed tarball.
tar -xzvf archive.tar.gz
Extract a gzip-compressed tarball.
ssh user@host
Connect to a remote host over SSH.
scp file user@host:/path
Copy a file to a remote host over SSH.
rsync -avz src/ dest/
Sync files, archive mode, verbose, compressed.
curl -I https://example.com
Fetch only the HTTP response headers.
wget https://example.com/file
Download a file over HTTP(S).
ps aux
List all running processes.
kill -9 PID
Force-kill a process by ID.
top
Live view of running processes and resource use.
df -h
Show disk space usage, human-readable.
du -sh dir
Show total size of a directory, human-readable.
tail -f file.log
Follow a file's output live (e.g. a log).
systemctl status service
Show the status of a systemd service.
systemctl restart service
Restart a systemd service.
journalctl -u service -f
Follow logs for a systemd unit live.
crontab -e
Edit the current user's cron jobs.
history | grep cmd
Search shell command history.
ln -s target linkname
Create a symbolic link.
awk '{print $1}' file
Print the first column of each line.
sed 's/old/new/g' file
Replace text in a file (stream editor).
export VAR=value
Set an environment variable for the session.
man command
Show the manual page for a command.
What is Linux commands reference?
A searchable cheat sheet for the Linux commands that come up constantly in day-to-day sysadmin and development work — file management, permissions, process control, and networking.
How to use it
Search by command name or a keyword describing what you want to do.
Example
Searching "permissions" surfaces chmod 755 file and chown user:group file.