{"id":43,"date":"2025-03-13T17:13:23","date_gmt":"2025-03-13T17:13:23","guid":{"rendered":"https:\/\/172.16.11.15\/?page_id=43"},"modified":"2025-09-03T19:57:48","modified_gmt":"2025-09-03T18:57:48","slug":"ubuntu-commands","status":"publish","type":"page","link":"https:\/\/7zeros.com\/?page_id=43","title":{"rendered":"Ubuntu Commands"},"content":{"rendered":"\n
\n

System & Services<\/h2>\n\n\n\n
lsb_release -a<\/td>ubuntu version<\/td><\/tr>
dmidecode
dmidecode -t <type><\/td>		system information
system type<\/td><\/tr>
hostname<\/td>display system hostname<\/td><\/tr>
date
timedatectl<\/td>		display time and date<\/td><\/tr>
service –status-all<\/td>list services status<\/td><\/tr>
systemctl status <service><\/td>check status of service<\/td><\/tr>
systemctl stop\/start\/restart <service><\/td>stop, start or restart service<\/td><\/tr>
top
htop<\/td>		view CPU, memory usage<\/td><\/tr>
free -h<\/td>memory usage<\/td><\/tr>
lshw -class disk
lshw -class disk -short<\/td>		list physical drives<\/td><\/tr>
parted -l
lsblk -l
lsblk -m
lsblk -f<\/td>		list drives<\/td><\/tr>
smartctl -a <\/drive\/path><\/td>hard drive health<\/td><\/tr>
lshw
lspci<\/td>		list hardware<\/td><\/tr>
lsblk -o model,name,size,fstype,label,mountpoint<\/td>identify partitions<\/td><\/tr>
mount
findmnt
df -aTh<\/td>		list mount points<\/td><\/tr>
lsof<\/td>list open files<\/td><\/tr>
reboot
poweroff<\/td>		power options<\/td><\/tr><\/tbody><\/table><\/figure>\n<\/div>\n\n\n\n

Packages<\/h2>\n\n\n\n
apt-get update<\/td>get new list of packages<\/td><\/tr>
apt-get upgrade<\/td>upgrade installed packages<\/td><\/tr>
apt-get dist-upgrade<\/td>intelligent package upgrade<\/td><\/tr>
apt-get install <package><\/td>install package<\/td><\/tr>
apt list –installed<\/td>list installed packages<\/td><\/tr>
<package> –version
apt-cache policy <package>
dpkg –status <package><\/td>		get version\/install details<\/td><\/tr>
which <package>
whereis <package>
locate <package>
dpkg –listfiles <package><\/td>		package file locations<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n

Storage<\/h2>\n\n\n\n
fdisk -l
parted -l
lsblk -l
lsblk -m
lsblk -f<\/td>		list drives<\/td><\/tr>
df<\/td>used space in KBs<\/td><\/tr>
df -h<\/td>used space in MBs, GBs<\/td><\/tr>
du<\/td>size on disk<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n

Networking<\/h2>\n\n\n\n
\/etc\/netplan<\/td>interfaces, dhcp & more<\/td><\/tr>
netplan apply<\/td>apply changes<\/td><\/tr>
ip link show<\/td>show interfaces, mac address<\/td><\/tr>
ethtool <interface><\/td>view interface details<\/td><\/tr>
ifconfig
ip address<\/td>		show ip address<\/td><\/tr>
nmcli device show <interface><\/td>similar to ipconfig output<\/td><\/tr>
dhlcient -r <interface>
dhclient <interface><\/td>		dhcp release\/renew<\/td><\/tr>
ip route list
route -n<\/td>		routing table<\/td><\/tr>
ping -c 4 bbc.co.uk<\/td>number of pings to send<\/td><\/tr>
ping -w 25 bbc.co.uk<\/td>stop pings after 25 seconds<\/td><\/tr>
ping -c 1000 -q bbc.co.uk<\/td>quiet output<\/td><\/tr>
ping -I <source-ip> bbc.co.uk<\/td>set source ip<\/td><\/tr>
ping -s 1438 -i 0.2 bbc.co.uk<\/td>set packet size and interval<\/td><\/tr>
fping -a -g <ntwk> 2>\/dev\/null<\/td>ping network subnet<\/td><\/tr>
dig TXT +short o-o.myaddr.1.google.com @ns1.google.com<\/td>view public ip<\/td><\/tr>
dig 7zeros.com
dig 7zeros.com MX +short<\/td>		dns lookup<\/td><\/tr>
ip link set <interface> down
ip link set dev <int> address <new-mac-address>
ip link set <interface> up<\/td>		steps to change mac address<\/td><\/tr>
ip link set <int> mtu <size><\/td>set mtu size<\/td><\/tr>
apt-get install vlan<\/td>install vlan package<\/td><\/tr>
ip link add link <int> name <int.vlan> type vlan id <vlan-id>
ip link set <int.vlan> up<\/td>		set vlan<\/td><\/tr>
ip route del default
ip route add default via <def-gw><\/td>		change default route<\/td><\/tr>
ip route add default via <def-gw> dev <int><\/td>change default route & specify interface<\/td><\/tr>
w
who
last
netstat<\/td>		view ssh sessions<\/td><\/tr>
ps -t <tty>
kill -HUP <bash-pid><\/td>		kill ssh session<\/td><\/tr>
snmpwalk -v 2c <host><\/td>snmp walk for v2<\/td><\/tr>
snmpwalk -v 2c -c <community> <host><\/td>snmp walk with community string<\/td><\/tr>
snmpwalk -v 3 -l <security> -u <username> <host><\/td>snmp walk for v3<\/td><\/tr>
speedtest-cli –simple
speedtest-cli –secure<\/td>		http test
https test<\/td><\/tr>
ssh-keygen -R <ip\/hostname><\/td>delete ssh keys<\/td><\/tr>
sha256sum <filename.xyz><\/td>hash verify checksum<\/td><\/tr>
ss<\/td>view endpoint sockets<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n

Port Security<\/h2>\n\n\n\n
nmap -Pn <host><\/td>skip host discovery<\/td><\/tr>
nmap -sP <network><\/td>scan network<\/td><\/tr>
nmap -sn <network><\/td>ping scan<\/td><\/tr>
nmap -sU <host><\/td>udp scan<\/td><\/tr>
nmap -sU -p <port> <host><\/td>specify port<\/td><\/tr>
telnet <host> <port><\/td>test port with telnet<\/td><\/tr>
nc -z <host> <port><\/td>test port with netcat<\/td><\/tr>
nc -v -u -z -w 3 <host> 1190-1194<\/td>test udp port<\/td><\/tr>
traceroute -T -p <port> <ip><\/td>traceroute on port number<\/td><\/tr>
lsof -i -P -n
nestat -lntu
ss -4altunp<\/td>		show localhost sockets, listening ports<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n

File Management<\/h2>\n\n\n\n
cd \/path\/to<\/td>change directory<\/td><\/tr>
cd ..<\/td>move up one directory<\/td><\/tr>
cd –<\/td>toggle between current and previous directory<\/td><\/tr>
pwd<\/td>print working directory<\/td><\/tr>
ls -l \/path\/to<\/td>list users & permissions<\/td><\/tr>
ls -R \/path\/to<\/td>list nested items<\/td><\/tr>
ls -a \/path\/to<\/td>list hidden files<\/td><\/tr>
tree -d \/path\/to\/
tree -L <level> \/path\/to
tree -a<\/td>		list directories in tree
list how many levels deep
list hidden files<\/td><\/tr>
cat <file>
less <file>
more <file><\/td>		view file<\/td><\/tr>
mkdir <directory-name><\/td>create directory<\/td><\/tr>
touch <filename><\/td>create file<\/td><\/tr>
mv <filename> \/path\/to
mv <file> <new-filename>
mv <file>{01..99}.txt \/path\/to<\/td>		move file
rename file
move range of files<\/td><\/tr>
cp<\/td>copy<\/td><\/tr>
rm <filename>
rm -d <directory>
rm -r <directory>
rm -i <file\/directory>
rm -rf <directory><\/td>		remove file
remove directory
recursive
prompt before removal
remove contents only<\/td><\/tr>
find \/ -type f -name <string><\/td>find files<\/td><\/tr>
find . -type d -name <string><\/td>find directories in working directory<\/td><\/tr>
find <path> -type f | wc -l<\/td>count all items recursively<\/td><\/tr>
ln -s \/source \/symbolic\/link<\/td>create soft symbolic link<\/td><\/tr>
apropos zip<\/td>list installed compression applications<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n

Users & Permissions<\/h2>\n\n\n\n
cat \/etc\/passwd
getent passwd<\/td>		list users<\/td><\/tr>
cat \/etc\/group
getent group<\/td>		list groups<\/td><\/tr>
useradd <username><\/td>create user<\/td><\/tr>
usermod -aG sudo <user><\/td>add user to sudo<\/td><\/tr>
passwd <username><\/td>change user password<\/td><\/tr>
su <username><\/td>change user<\/td><\/tr>
addgroup <group-name><\/td>create new group<\/td><\/tr>
usermod -a -G <group> <user><\/td>add user to user group<\/td><\/tr>
deluser <user> <group><\/td>delete user from group<\/td><\/tr>
mkhomedir_helper <user><\/td>create user home directory<\/td><\/tr>
chown -R <user>:<group> \/path<\/td>local user permissions<\/td><\/tr>
chmod ugo+rwx \/path\/to
chmod 777 \/path\/to<\/td>		change folder permissions
(u=user, g=group, o=others)
r (read): 4, w (write): 2, x (execute): 1<\/td><\/tr>
sudo !!<\/td>run previous command with sudo<\/td><\/tr>
curl https:\/\/download\/url
wget https:\/\/download\/url<\/td>		download from url<\/td><\/tr>
wget https:\/\/download <short-filename.xyz><\/td>shortened download filename<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n

Firewall<\/h2>\n\n\n\n
ufw status<\/td>show ufw firewall status<\/td><\/tr>
ufw allow 53
ufw allow 25\/tcp
ufw reject telnet<\/td>		allow\/block ports through firewall<\/td><\/tr>
ufw allow in http
ufw reject out smtp<\/td>		in and out rules<\/td><\/tr>
ipset list<\/td>list iptables address lists<\/td><\/tr>
iptables -S
iptables -L<\/td>		list iptables firewall rules<\/td><\/tr>
iptables -t nat -L
iptables -t nat -L -n -v<\/td>		list nat rules<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n

Packet Capture<\/h2>\n\n\n\n
tcpdump -D<\/td>list capture interfaces<\/td><\/tr>
tcpdump -i <interface><\/td>capture on interface<\/td><\/tr>
tcpdump -w <filename.pcap><\/td>capture to file<\/td><\/tr>
tcpdump -r <filename.pcap><\/td>read captured packets<\/td><\/tr>
tcpdump port 22<\/td>filter capture on port<\/td><\/tr>
tcpdump tcp<\/td>filter capture on tcp only<\/td><\/tr>
tcpdump net <subnet><\/td>capture on subnet range<\/td><\/tr>
tcpdump host <src> and <dst><\/td>capture 2-way traffic<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n

Logs<\/h2>\n\n\n\n
dmesg<\/td>display kernel buffer<\/td><\/tr>
\/var\/log<\/td>log files location<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n

Vim<\/h2>\n\n\n\n
vim <filename><\/td>create\/edit file<\/td><\/tr>
i<\/td>INSERT to make changes<\/td><\/tr>
ESC key<\/td>exit out of INSERT mode<\/td><\/tr>
:q!<\/td>quit without making changes<\/td><\/tr>
:wq<\/td>write and quit<\/td><\/tr>
gg<\/td>go to beginning of file<\/td><\/tr>
ggVG<\/td>select all<\/td><\/tr>
shift + g<\/td>go to end of file<\/td><\/tr>
:<line-number><\/td>go to line number<\/td><\/tr>
\/<string><\/td>search for string<\/td><\/tr>
:s\/<pattern>\/<replacement>\/<\/td>find and replace next occurrence<\/td><\/tr>
:%s\/<pattern>\/<replacement>\/g<\/td>find and replace all occurrences<\/td><\/tr>
dG<\/td>delete all text<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n

Python<\/h2>\n\n\n\n
python3 -m venv <venv_name><\/td>create new virtual environment<\/td><\/tr>
source <venv_name>\/bin\/activate<\/td>activate new virtual environment<\/td><\/tr>
deactivate<\/td>exit current virtual environment<\/td><\/tr>
pip3 install <module><\/td>install python module<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n

OpenSSL<\/h2>\n\n\n\n
openssl pkcs12 -export -out cert.p12 -in <cert>.pem -inkey <privkey>.pem<\/td>export cert and key<\/td><\/tr><\/tbody><\/table><\/figure>\n","protected":false},"excerpt":{"rendered":"

System & Services lsb_release -a ubuntu version dmidecodedmidecode -t <type> system informationsystem type hostname display system hostname datetimedatectl display time and date service –status-all list services status systemctl status <service> check status of service systemctl stop\/start\/restart <service> stop, start or restart service tophtop view CPU, memory usage free -h memory usage lshw -class disklshw -class […]<\/p>\n","protected":false},"author":1,"featured_media":0,"parent":0,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"footnotes":""},"class_list":["post-43","page","type-page","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/7zeros.com\/index.php?rest_route=\/wp\/v2\/pages\/43","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/7zeros.com\/index.php?rest_route=\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/7zeros.com\/index.php?rest_route=\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/7zeros.com\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/7zeros.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=43"}],"version-history":[{"count":42,"href":"https:\/\/7zeros.com\/index.php?rest_route=\/wp\/v2\/pages\/43\/revisions"}],"predecessor-version":[{"id":365,"href":"https:\/\/7zeros.com\/index.php?rest_route=\/wp\/v2\/pages\/43\/revisions\/365"}],"wp:attachment":[{"href":"https:\/\/7zeros.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=43"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}