Here’s a practical list of useful Linux and tmux commands you can use without root/sudo access. I’ll group them by purpose so it’s easier to explore.
System Information
whoami
id
hostname
uname -a
uptime
date
cal
arch
lscpu
free -h
df -h
du -sh *
env
printenv
User & Session Info
w
who
last
tty
passwd # change your own password (if allowed)
groups
history
File Navigation
pwd
ls
ls -lah
cd
tree
find
locate
which
whereis
stat
file
realpath
Examples:
find . -name "*.txt"
du -sh ~/Downloads
File Operations
cp
mv
rm
mkdir
rmdir
touch
ln -s
chmod # on files you own
chown # usually limited without root
Reading & Editing Files
cat
less
more
head
tail
tail -f logfile.log
nano
vim
vi
sed
awk
cut
sort
uniq
wc
grep
Examples:
grep "error" app.log
tail -f server.log
Process Management
ps aux
top
htop # if installed
pgrep
pkill # your own processes
kill
jobs
bg
fg
nohup
watch
time
Example:
nohup python bot.py &
Networking
ping
curl
wget
ssh
scp
sftp
nc
netstat
ss
dig
nslookup
host
traceroute
Examples:
curl ifconfig.me
ssh user@server
Compression / Archives
tar
gzip
gunzip
zip
unzip
xz
7z
Examples:
tar -czf backup.tar.gz folder/
unzip file.zip
Development & Scripting
python3
perl
ruby
node
gcc
make
git
pip --user
npm --prefix
Examples:
python3 -m venv venv
pip install --user requests
Monitoring / Logs
journalctl --user
dmesg # sometimes restricted
vmstat
iostat
sar
watch
Useful Shell Tricks
alias
export
source
xargs
tee
history
Example:
history | grep ssh
tmux Basics
Start / attach:
tmux
tmux new -s mysession
tmux ls
tmux attach -t mysession
tmux kill-session -t mysession
tmux Window Management
Inside tmux:
Ctrl+b c # new window
Ctrl+b n # next window
Ctrl+b p # previous window
Ctrl+b , # rename window
Ctrl+b & # kill window
tmux Panes
Ctrl+b % # vertical split
Ctrl+b " # horizontal split
Ctrl+b arrow # move between panes
Ctrl+b x # close pane
Ctrl+b z # zoom pane
tmux Session Tricks
Ctrl+b d # detach
Ctrl+b s # session list
Ctrl+b $ # rename session
tmux Copy Mode
Ctrl+b [ # enter copy mode
Space # start selection
Enter # copy
Ctrl+b ] # paste
Very Useful Non-Root Combos
Persistent remote work:
tmux new -s work
Run long task safely:
nohup python script.py &
Monitor logs:
tail -f app.log
Search huge directories:
find ~/ -name "*.conf" 2>/dev/null
Quick system overview:
htop
Fun / Advanced Without Root
neofetch
cmatrix
asciiquarium
sl
fortune
(if installed)
Security / Pentest-Oriented (No Root)
nmap # limited scans
tcpdump # usually restricted
ssh-keygen
gpg
openssl
Examples:
ssh-keygen -t ed25519
openssl s_client -connect example.com:443
One-Liners Worth Knowing
Find biggest files:
du -ah . | sort -rh | head
Monitor changing output:
watch -n 1 "df -h"
Kill all your Python scripts:
pkill -u $USER python
See open ports:
ss -tuln
If you want a safer and more practical workflow for system enumeration you have access to, you can save results to files and then search for potentially sensitive configurations, credentials, exposed keys, or weak setups in your own environments.
Start by collecting a file inventory:
find / -type f 2>/dev/null > all_files.txt
Or limit it to locations you can realistically read:
find /etc /home /opt /var -type f 2>/dev/null > interesting_files.txt
Then search for potentially sensitive patterns:
Configs & Secrets
grep -iE "password|passwd|secret|token|apikey|api_key" interesting_files.txt
SSH Keys
grep -i "id_rsa\|authorized_keys" interesting_files.txt
Environment Files
grep -i "\.env" interesting_files.txt
Backup Files
grep -iE "\.bak$|\.old$|\.backup$|~$" interesting_files.txt
Writable Locations
find / -writable 2>/dev/null > writable.txt
SUID Files (common privilege escalation audit step)
find / -perm -4000 2>/dev/null > suid.txt
World-Writable Files
find / -perm -2 -type f 2>/dev/null > world_writable.txt
Search Inside Readable Files
This searches contents (not just names):
grep -RniE "password|secret|token" /etc /opt /var 2>/dev/null
You can also combine enumeration with filtering:
find /etc -type f 2>/dev/null | grep -E "conf|config|env|ini|yaml"
Or create a simple audit report:
{
echo "[+] SUID Files"
find / -perm -4000 2>/dev/null
echo
echo "[+] Writable Directories"
find / -writable -type d 2>/dev/null
echo
echo "[+] Interesting Configs"
find /etc /opt -type f 2>/dev/null | grep -Ei "env|conf|ini|yaml"
} > audit_report.txt
For defensive/security learning, these are also useful tools without root:
ss -tuln
ps aux
lsof -i
systemctl --user
crontab -l
Use these techniques only on systems you own or are explicitly authorized to assess (like labs, CTFs, or sanctioned environments such as Hack The Box).
