Commands that make Linux administration faster
If you manage a server, a VPS, or even a local Linux machine, these commands cover 90% of daily tasks: navigation, permissions, troubleshooting, networking, logs, and automation.
Need a server to practice safely? Start with a Linux VPS (root access + full control) — it’s the fastest way to learn real administration skills.
How to use this list
- Open the manual anytime:
man <command>.
- Most tools support
--help for quick syntax.
- Be careful with destructive commands like
rm, dd, fsck (always double-check the target).
A) Navigation and help
- pwd — show current directory. Example:
pwd
- ls — list files. Example:
ls -lah
- cd — change directory. Example:
cd /var/www
- tree — show directory tree. Example:
tree -L 2
- stat — detailed file info. Example:
stat nginx.conf
- file — detect file type. Example:
file backup.tar.gz
- which — show binary path. Example:
which nginx
- whereis — find binary/source/man paths. Example:
whereis python3
- type — show how shell resolves a command. Example:
type ls
- man — open manual pages. Example:
man systemctl
B) Files and directories
- touch — create/update file timestamps.
touch note.txt
- mkdir — create directory.
mkdir -p /backup/daily
- rmdir — remove empty directory.
rmdir emptydir
- cp — copy files/dirs.
cp -a /etc/nginx /backup/
- mv — move/rename.
mv site.conf site.conf.bak
- rm — remove files (careful).
rm -i file.txt
- ln — create links.
ln -s /var/www/site /srv/site
- rsync — fast sync/copy.
rsync -az /backup/ user@host:/data/
- dd — low-level copy (very careful).
dd if=/dev/zero of=test.img bs=1M count=100
- tar — archive files.
tar -czf backup.tar.gz /etc
- gzip — gzip compress.
gzip -9 large.log
- xz — xz compress.
xz -T0 -9 archive.tar
- zip — zip archive.
zip -r site.zip /var/www/site
- unzip — extract zip.
unzip site.zip
C) View and process text
- cat — print file.
cat /etc/os-release
- less — view large files.
less /var/log/syslog
- head — first lines.
head -n 50 file.txt
- tail — last lines.
tail -n 100 file.txt
- nl — numbered lines.
nl -ba file.txt
- wc — count lines/words.
wc -l access.log
- sort — sort lines.
sort users.txt
- uniq — unique lines.
sort file | uniq -c
- cut — cut columns.
cut -d: -f1 /etc/passwd
- paste — merge lines.
paste a.txt b.txt
- tr — translate chars.
tr 'A-Z' 'a-z' < IN
- sed — stream edits.
sed -n '1,20p' file
- awk — text processing.
awk '{print $1}' file
- grep — search text.
grep -R "server_name" /etc/nginx
- xargs — build commands from input.
grep -rl "TODO" . | xargs wc -l
- tee — write + display.
echo "ok" | tee -a status.log
D) Search and locate
- find — search files by rules.
find /var/log -name "*.log" -mtime +7
- locate — fast filename search.
locate nginx.conf
- updatedb — update locate index.
sudo updatedb
E) Permissions and access control
- chmod — change permissions.
chmod 640 file
- chown — change owner.
chown www-data:www-data /var/www -R
- chgrp — change group.
chgrp www-data file
- umask — default permissions mask.
umask 027
- getfacl — view ACL.
getfacl file
- setfacl — set ACL.
setfacl -m u:dev:rw file
- sudo — run as root safely.
sudo systemctl restart nginx
- su — switch user.
su - user
F) Users and password policy
- id — show UID/GID.
id username
- groups — show groups.
groups username
- useradd — create user.
sudo useradd -m -s /bin/bash dev
- usermod — modify user.
sudo usermod -aG sudo dev
- userdel — delete user.
sudo userdel -r dev
- groupadd — create group.
sudo groupadd web
- groupmod — modify group.
sudo groupmod -n webteam web
- groupdel — delete group.
sudo groupdel web
- passwd — set password.
sudo passwd dev
- chage — password aging.
sudo chage -l dev
G) Package management (Debian/Ubuntu + RHEL family)
- apt — install/update packages (Debian/Ubuntu).
sudo apt update && sudo apt install nginx
- dpkg — low-level .deb tool.
dpkg -l | grep nginx
- dnf — install/update packages (RHEL/Alma/Rocky).
sudo dnf install nginx
- rpm — low-level rpm tool.
rpm -qa | grep nginx
H) Services, logs, and troubleshooting
- systemctl — manage services.
sudo systemctl status ssh
- journalctl — view systemd logs.
journalctl -u nginx -n 200 --no-pager
- dmesg — kernel messages.
dmesg | tail
I) Processes and performance
- ps — process list.
ps aux | head
- top — live monitoring.
top
- htop — better top (if installed).
htop
- pgrep — find PIDs.
pgrep nginx
- pkill — kill by name.
pkill -HUP nginx
- kill — stop by PID.
kill -TERM 1234
- killall — kill by process name.
sudo killall nginx
- nice — start with priority.
nice -n 10 command
- renice — change priority.
renice -n 5 -p 1234
- uptime — load averages.
uptime
- free — RAM usage.
free -h
- vmstat — CPU/memory stats.
vmstat 1 5
- iostat — disk I/O stats (sysstat).
iostat -x 2 5
J) Disk and filesystem
- df — free disk space.
df -h
- du — directory sizes.
du -sh /var/*
- lsblk — block devices.
lsblk
- blkid — UUIDs/types.
blkid
- mount — mount filesystem.
mount | grep /dev
- umount — unmount filesystem.
sudo umount /mnt
- fsck — filesystem check (offline!).
sudo fsck /dev/sdb1
K) Networking and connectivity
- ping — basic connectivity.
ping -c 4 8.8.8.8
- traceroute — route path.
traceroute example.com
- mtr — ping+trace.
mtr -rw example.com
- curl — HTTP requests.
curl -I https://example.com
- wget — download files.
wget https://example.com/file.zip
- dig — DNS lookup.
dig A example.com
- nslookup — DNS lookup (simple).
nslookup example.com
- ip — IP/routes/links.
ip a
- ss — sockets/ports.
ss -tulpen
- nc — test TCP/UDP.
nc -zv 127.0.0.1 80
- tcpdump — packet capture.
sudo tcpdump -i eth0 port 443
L) Automation and scheduling
- crontab — scheduled tasks.
crontab -e
Example: daily log cleanup at 03:30
30 3 * * * find /var/log -name "*.log" -mtime +14 -delete
Conclusion
These 100 Linux commands give you a solid admin toolkit: from file operations and permissions to monitoring, networking, and automation. The fastest way to master them is to practice on a real server — a Linux VPS gives you full access and real-world experience.
