Linux commands cheat sheet

#Introduction

In this tutorial, The ultimate Linux commands cheat sheet. On Linux operating system and other UNIX-like operating systems.

System Information

Linux Commands for System Information. You want to query information about your system.

CommandsDescriptionFor example
whoamiOutput the current user using the Linux system[vagrant@localhost ~]$ whoami
vagrant
wwho or which systems are online especially[vagrant@localhost ~]$ w
20:29:06 up 3 min, 1 user, load average: 0.00, 0.00, 0.00
USER TTY FROM LOGIN@ IDLE JCPU PCPU WHAT
vagrant pts/0 10.0.2.2 20:27 2.00s 0.01s 0.00s w
calOutputs the present month’s calendar.[vagrant@localhost ~]$ cal
September 2021
Su Mo Tu We Th Fr Sa
1 2 3 4
5 6 7 8 9 10 11
12 13 14 15 16 17 18
19 20 21 22 23 24 25
26 27 28 29 30
dateDisplaying the current date and time.[vagrant@localhost ~]$ date
Tue Sep 21 20:30:00 +07 2021
last rebootA useful command of how many times your system restarted.[vagrant@localhost ~]$ last reboot
reboot system boot 3.10.0-1127.el7. Tue Sep 21 20:25 – 20:30 (00:04)
reboot system boot 3.10.0-1127.el7. Tue Sep 21 14:42 – 17:26 (02:44)
reboot system boot 3.10.0-1127.el7. Sat Sep 18 20:56 – 22:00 (01:03)
reboot system boot 3.10.0-1127.el7. Sat Sep 18 14:37 – 22:00 (07:22)
wtmp begins Sat Sep 18 14:37:54 2021
hostname -IOutputs the assigned IP address your system is currently[vagrant@localhost ~]$ hostname -I
10.0.2.15 192.168.3.4 172.17.0.1
hostnameOutputs your system’s hostname[vagrant@localhost ~]$ hostname
localhost.localdomain
uptimeOutputs how long your Linux system has been active[vagrant@localhost ~]$ uptime
20:31:27 up 5 min, 1 user, load average: 0.00, 0.00, 0.00
lsb_release -aYou can obtain information specific to your Linux distribution.
This command displays its Distributor ID, Description, Release, and Codename.
vagrant@vagrant:~$ lsb_release -a
No LSB modules are available.
Distributor ID: Ubuntu
Description: Ubuntu 21.04
Release: 21.04
Codename: hirsute
uname -rOutputs the kernel release information[vagrant@localhost ~]$ uname -r
3.10.0-1127.el7.x86_64
uname -aDisplays basic system information like machine name, etc.[vagrant@localhost ~]$ uname -a
Linux localhost.localdomain 3.10.0-1127.el7.x86_64 #1 SMP Tue Mar 31 23:36:51 UTC 2020 x86_64 x86_64 x86_64 GNU/Linux

File Permissions

Linux Commands for File Permissions. File permissions in Linux relate to Read (r), Write (w), and Execute (x) privileges.

Commands Description For example
ls -lOutputs the file type and the file permissions[root@localhost vagrant]# ls -l
total 0
-rw-rw-r–. 1 vagrant vagrant 0 Sep 21 20:34 devopsroles.com
drwxr-xr-x. 2 vagrant vagrant 6 Sep 13 20:12 share
chown user:group file_nameChange The user and group privileges[root@localhost vagrant]# chown huupv:root devopsroles.com
[root@localhost vagrant]# ls -l devopsroles.com
-rw-rw-r–. 1 huupv root 0 Sep 21 20:34 devopsroles.com
chmod 777 file_nameEveryone access the file[root@localhost vagrant]# chmod 777 devopsroles.com
[root@localhost vagrant]# ls -l devopsroles.com
-rwxrwxrwx. 1 huupv root 0 Sep 21 20:34 devopsroles.com
chmod 755 file_nameThe owner of the file: Read, Write, Execute
other users and Group will only have read and executed permissions.
[root@localhost vagrant]# chmod 755 devopsroles.com
[root@localhost vagrant]# ls -l devopsroles.com
-rwxr-xr-x. 1 huupv root 0 Sep 21 20:34 devopsroles.com
chmod 766 file_name The owner of the file: Read, Write, Execute
other users and Group will only have Read and Write permissions.
[root@localhost vagrant]# chmod 766 devopsroles.com
[root@localhost vagrant]# ls -l devopsroles.com
-rwxrw-rw-. 1 huupv root 0 Sep 21 20:34 devopsroles.com
touch -a -tUseful in creating or modifying a file timestamp.
-a = accessed
-m = modified
-t = timestamp – use [[CC]YY]MMDDhhmm[.ss] time format
[root@localhost vagrant]# touch -a -t 201902090123.30 devopsroles.com
[root@localhost vagrant]# stat devopsroles.com
File: ‘devopsroles.com’

Size: 0 Blocks: 0 IO Block: 4096 regular empty file
Device: 801h/2049d Inode: 5323348 Links: 1
Access: (0766/-rwxrw-rw-) Uid: ( 1001/ huupv) Gid: ( 0/ root)
Context: unconfined_u:object_r:user_home_t:s0
Access: 2019-02-09 01:23:30.000000000 +0700
Modify: 2021-09-21 20:34:35.629225064 +0700
Change: 2021-09-21 20:43:41.338885218 +0700
Birth: –
chgrp group_name filenameUseful in changing the group permission of a file.[root@localhost vagrant]# ls -l devopsroles.com
-rwxr-xr-x. 1 huupv root 0 Sep 21 20:34 devopsroles.com
[root@localhost vagrant]# chgrp vagrant devopsroles.com
[root@localhost vagrant]# ls -l devopsroles.com
-rwxr-xr-x. 1 huupv vagrant 0 Sep 21 20:34 devopsroles.com
chmod -c -RAssign a file the read, write, and execute permissions.[root@localhost vagrant]# ls -l devopsroles.com
-rwxr-xr-x. 1 huupv vagrant 0 Sep 21 20:34 devopsroles.com
[root@localhost vagrant]# chmod -c -R 777 devopsroles.com
mode of ‘devopsroles.com’ changed from 0755 (rwxr-xr-x) to 0777 (rwxrwxrwx)
[root@localhost vagrant]# ls -l devopsroles.com
-rwxrwxrwx. 1 huupv vagrant 0 Sep 21 20:34 devopsroles.com

Hardware Information

Commands Description For example
cat /proc/cpuinfoOutputs CPU information of your machine.[vagrant@localhost ~]$ cat /proc/cpuinfo
processor : 0
vendor_id : GenuineIntel
cpu family : 6
model : 167
model name : 11th Gen Intel(R) Core(TM) i7-11700 @ 2.50GHz
stepping : 1
cpu MHz : 2496.004
cache size : 16384 KB
……
cat /proc/meminfoOutputs Memory information[vagrant@localhost ~]$ cat /proc/meminfo
MemTotal: 498684 kB
MemFree: 131816 kB
MemAvailable: 343212 kB
Buffers: 2068 kB
Cached: 207228 kB
SwapCached: 0 kB
Active: 107336 kB
…..
free -hOutputs both free and used machine memory info.[vagrant@localhost ~]$ free -h
total used free shared buff/cache available
Mem: 486M 134M 128M 4.5M 223M 334M
Swap: 2.0G 0B 2.0G
lshwOutputs the system’s hardware configuration information.[vagrant@localhost ~]$ sudo lshw -short
H/W path Device Class Description
system VirtualBox
/0 bus VirtualBox
/0/0 memory 128KiB BIOS
/0/1 memory 512MiB System memory
/0/2 processor 11th Gen Intel(R) Core(TM) i7-11700 @ 2.50GHz
/0/100 bridge 440FX – 82441FX PMC [Natoma]
/0/100/1 bridge 82371SB PIIX3 ISA [Natoma/Triton II]
/0/100/1.1 scsi0 storage 82371AB/EB/MB PIIX4 IDE
/0/100/1.1/0.0.0 /dev/sda disk 42GB VBOX HARDDISK
/0/100/1.1/0.0.0/1 volume 39GiB Linux filesystem partition
/0/100/2 display VirtualBox Graphics Adapter
/0/100/3 eth0 network 82540EM Gigabit Ethernet Controller
/0/100/4 generic VirtualBox Guest Service
/0/100/5 multimedia 82801AA AC’97 Audio Controller
/0/100/7 bridge 82371AB/EB/MB PIIX4 ACPI
/0/100/8 eth1 network 82540EM Gigabit Ethernet Controller
/0/3 input PnP device PNP0303
/0/4 input PnP device PNP0f03
/1 docker0 network Ethernet interface
lsblkOutputs the system’s block devices information.[vagrant@localhost ~]$ lsblk
NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
sda 8:0 0 40G 0 disk
└─sda1 8:1 0 40G 0 part /
lspci -tvOutputs the system’s PCI devices.[vagrant@localhost ~]$ lspci -tv
-[0000:00]-+-00.0 Intel Corporation 440FX – 82441FX PMC [Natoma]
+-01.0 Intel Corporation 82371SB PIIX3 ISA [Natoma/Triton II]
+-01.1 Intel Corporation 82371AB/EB/MB PIIX4 IDE
+-02.0 InnoTek Systemberatung GmbH VirtualBox Graphics Adapter
+-03.0 Intel Corporation 82540EM Gigabit Ethernet Controller
+-04.0 InnoTek Systemberatung GmbH VirtualBox Guest Service
+-05.0 Intel Corporation 82801AA AC’97 Audio Controller
+-07.0 Intel Corporation 82371AB/EB/MB PIIX4 ACPI
-08.0 Intel Corporation 82540EM Gigabit Ethernet Controller
lsusb -tvOutputs the system’s USB devices.
dmidecodeOutputs the system’s hardware information on DMI/SMBIOS related to the BIOS.[vagrant@localhost ~]$ sudo dmidecode
dmidecode 3.2
Getting SMBIOS data from sysfs.
SMBIOS 2.5 present.
10 structures occupying 450 bytes.
Table at 0x000E1000.
Handle 0x0000, DMI type 0, 20 bytes
BIOS Information
Vendor: innotek GmbH
Version: VirtualBox
Release Date: 12/01/2006
Address: 0xE0000
…..
dmesgOutputs the kernel ring buffer messages.[vagrant@localhost ~]$ dmesg
[ 0.000000] Initializing cgroup subsys cpuset
[ 0.000000] Initializing cgroup subsys cpu
[ 0.000000] Initializing cgroup subsys cpuacct
[ 0.000000] Linux version 3.10.0-1127.el7.x86_64 (mockbuild@kbuilder.bsys.centos.org) (gcc version 4.8.5 20150623 (Red Hat 4.8.5-39) (GCC) ) #1 SMP Tue Mar 31 23:36:51 UTC 2020
[ 0.000000] Command line: BOOT_IMAGE=/boot/vmlinuz-3.10.0-1127.el7.x86_64 root=UUID=1c419d6c-5064-4a2b-953c-05b2c67edb15 ro no_timer_check console=tty0 console=ttyS0,115200n8 net.ifnames=0 biosdevname=0 elevator=noop crashkernel=auto LANG=en_US.UTF-8
[ 0.000000] e820: BIOS-provided physical RAM map:
[ 0.000000] BIOS-e820: [mem 0x0000000000000000-0x000000000009fbff] usable
[ 0.000000] BIOS-e820: [mem 0x000000000009fc00-0x000000000009ffff] reserved
….
lscpuOutputs information about the CPU and processing units.[vagrant@localhost ~]$ lscpu
Architecture: x86_64
CPU op-mode(s): 32-bit, 64-bit
Byte Order: Little Endian
CPU(s): 1
On-line CPU(s) list: 0
Thread(s) per core: 1
Core(s) per socket: 1
Socket(s): 1
NUMA node(s): 1
Vendor ID: GenuineIntel
CPU family: 6
…..
lsscsiLists out the SCSI/SATA devices like hard drives and optical drives.[vagrant@localhost ~]$ lsscsi
[0:0:0:0] disk ATA VBOX HARDDISK 1.0 /dev/sda

Networking

Commands Description For example
ping hostname_or_IPUseful in analyzing the responsiveness of a hostname connected to a network.[vagrant@localhost ~]$ ping 192.168.3.4
PING 192.168.3.4 (192.168.3.4) 56(84) bytes of data.
64 bytes from 192.168.3.4: icmp_seq=1 ttl=64 time=0.017 ms
64 bytes from 192.168.3.4: icmp_seq=2 ttl=64 time=0.021 ms
64 bytes from 192.168.3.4: icmp_seq=3 ttl=64 time=0.021 ms
tcpdumpUsed to dump network traffic.[vagrant@localhost ~]$ sudo tcpdump -i eth0
netstat -r -vPrints network routing, information, and connections.[vagrant@localhost ~]$ netstat -r -v
Kernel IP routing table
Destination Gateway Genmask Flags MSS Window irtt Iface
default gateway 0.0.0.0 UG 0 0 0 eth0
10.0.2.0 0.0.0.0 255.255.255.0 U 0 0 0 eth0
172.17.0.0 0.0.0.0 255.255.0.0 U 0 0 0 docker0
192.168.3.0 0.0.0.0 255.255.255.0 U 0 0 0 eth1
ip addr showOutputs network interfaces and their related IP addresses.
ifconfigOutputs configured network interfaces’ IP addresses.
whois domain_nameReveals more information regarding an active domain name on the internet.[vagrant@localhost ~]$ whois devopsroles.com
Domain Name: DEVOPSROLES.COM
Registry Domain ID: 2245154670_DOMAIN_COM-VRSN
……
dig domain_nameReveals DNS information and configuration regarding an active domain name.
dig -x hostIt is applicable when dealing with DNS and will reverse lookup an active domain.[vagrant@localhost ~]$ dig -x huuphan.com
; <<>> DiG 9.11.4-P2-RedHat-9.11.4-26.P2.el7_9.7 <<>> -x huuphan.com
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NXDOMAIN, id: 43438
;; flags: qr rd ra ad; QUERY: 1, ANSWER: 0, AUTHORITY: 1, ADDITIONAL: 1
;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 512
;; QUESTION SECTION:
;com.huuphan.in-addr.arpa. IN PTR
;; AUTHORITY SECTION:
in-addr.arpa. 3486 IN SOA b.in-addr-servers.arpa. nstld.iana.org. 2021090215 1800 900 604800 3600
;; Query time: 34 msec
;; SERVER: 10.0.2.3#53(10.0.2.3)
;; WHEN: Wed Sep 22 20:23:37 +07 2021
;; MSG SIZE rcvd: 121
dig -x IP_addressIt will reverse lookup an active IP address.[vagrant@localhost ~]$ dig -x 172.67.137.70
; <<>> DiG 9.11.4-P2-RedHat-9.11.4-26.P2.el7_9.7 <<>> -x 172.67.137.70
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NXDOMAIN, id: 52165
;; flags: qr rd ra; QUERY: 1, ANSWER: 0, AUTHORITY: 1, ADDITIONAL: 1
;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 512
;; QUESTION SECTION:
;70.137.67.172.in-addr.arpa. IN PTR
;; AUTHORITY SECTION:
67.172.in-addr.arpa. 1800 IN SOA cruz.ns.cloudflare.com. dns.cloudflare.com. 2034580120 10000 2400 604800 3600
;; Query time: 41 msec
;; SERVER: 10.0.2.3#53(10.0.2.3)
;; WHEN: Wed Sep 22 20:24:27 +07 2021
;; MSG SIZE rcvd: 117
host domain_nameIt will lookup the IP address of an active domain[vagrant@localhost ~]$ host huuphan.com
huuphan.com has address 104.21.73.16
huuphan.com has address 172.67.137.70
huuphan.com has IPv6 address 2606:4700:3032::6815:4910
huuphan.com has IPv6 address 2606:4700:3031::ac43:8946
huuphan.com mail is handled by 10 aspmx2.googlemail.com.
huuphan.com mail is handled by 1 aspmx.l.google.com.
huuphan.com mail is handled by 5 alt1.aspmx.l.google.com.
huuphan.com mail is handled by 10 aspmx3.googlemail.com.
huuphan.com mail is handled by 5 alt2.aspmx.l.google.com.
wget file_nameUseful in downloading a file from a specified domain namewget https://www.huuphan.com/filename.zip
ifconfig -aOutputs all the network interface details
ifconfig eth0Outputs eth0 configuration and address details.
ethtool eth0Used to manage hardware and network drivers query and control settings[vagrant@localhost ~]$ ethtool eth0
Settings for eth0:
Supported ports: [ TP ]
Supported link modes: 10baseT/Half 10baseT/Full
100baseT/Half 100baseT/Full
1000baseT/Full
Supported pause frame use: No
Supports auto-negotiation: Yes
Supported FEC modes: Not reported
Advertised link modes: 10baseT/Half 10baseT/Full
100baseT/Half 100baseT/Full
1000baseT/Full
Advertised pause frame use: No
Advertised auto-negotiation: Yes
Advertised FEC modes: Not reported
Speed: 1000Mb/s
Duplex: Full
Port: Twisted Pair
PHYAD: 0
Transceiver: internal
Auto-negotiation: on
MDI-X: off (auto)
Cannot get wake-on-lan settings: Operation not permitted
Current message level: 0x00000007 (7)
drv probe link
Link detected: yes

Archives and File Compression

Commands Description For example
tar cvf compressed_file_name.tar file_name # creating
tar xvf compressed_file_name.tar file_name # extracting
creating or extracting files with .tar[vagrant@localhost ~]$ tar cvf share.tar share
share/
[vagrant@localhost ~]$ tar xvf share.tar
share/
tar czf compressed_file_name.tar.gzcompresses a tar file into a gzip archive.
tar cjf archive.tar.bz2 foldercompresses a tar file inside a bz2 archive.[vagrant@localhost ~]$ tar cjf archive.tar.bz2 share
[vagrant@localhost ~]$ ll
total 20
-rw-rw-r–. 1 vagrant vagrant 150 Sep 23 07:51 archive.tar.bz2
tar xjf archive.tar.bz2extracts a tar file compressed inside a bz2 archive.
gzip, gunzip, zcat file_namecreating, extracting. or viewing files with .gz extension
uuencode, uudecodecreating or extracting files with .Z extension.
zip, unzip -vcreating or extracting files with .Zip extension.[vagrant@localhost ~]$ zip -r share.zip share
adding: share/ (stored 0%)
adding: share/abc.txt (stored 0%)
[vagrant@localhost ~]$ ls -l share.zip
-rw-rw-r–. 1 vagrant vagrant 316 Sep 23 07:56 share.zip

[vagrant@localhost ~]$ unzip -v share.zip
Archive: share.zip
Length Method Size Cmpr Date Time CRC-32 Name
——– —— ——- —- ———- —– ——– —-
0 Stored 0 0% 09-23-2021 07:50 00000000 share/
0 Stored 0 0% 09-23-2021 07:50 00000000 share/abc.txt
——– ——- — ——-
0 0 0% 2 files
bzip2, bunzip2creating or extracting files with .bz2 extension.
rarcreating or extracting files with .rar extension.

Installing Packages

Commands Description For example
yum search keywordSearch a package installation based on specific keywords.[vagrant@localhost ~]$ yum search nginx
Loaded plugins: fastestmirror
Determining fastest mirrors
base: mirror.vietnix.vn
epel: mirror.xeonbd.com
extras: mirror.vietnix.vn
updates: mirror.vietnix.vn
=============== N/S matched: nginx ==========
collectd-nginx.x86_64 : Nginx plugin for collectd
munin-nginx.noarch : NGINX support for Munin resource monitoring
nginx-all-modules.noarch : A meta package that installs all available Nginx modules
nginx-filesystem.noarch : The basic directory layout for the Nginx serve
……
yum install package.rpmThe use of a YUM package manager to install and configure a package.
yum info packageTo find more information about a package before optionally proceeding with its installation.[vagrant@localhost ~]$ yum info nginx
Loaded plugins: fastestmirror
Loading mirror speeds from cached hostfile
base: mirror.vietnix.vn
epel: mirror.xeonbd.com
extras: mirror.vietnix.vn
updates: mirror.vietnix.vn
Available Packages
Name : nginx
Arch : x86_64
Epoch : 1
Version : 1.20.1
Release : 2.el7
Size : 586 k
Repo : epel/x86_64
Summary : A high performance web server and reverse proxy server
URL : https://nginx.org
License : BSD
Description : Nginx is a web server and a reverse proxy server for HTTP, SMTP, POP3 and
: IMAP protocols, with a strong focus on high concurrency, performance and low
: memory usage.
rpm -i package.rpmTo install a downloaded RPM package.
yum remove packageTo uninstall or remove a Yum package from your system.
tar zxvf sourcecode.tar.gz
cd sourcecode
./configure
make
make install
Command sequence to install a package software that comes as a source code.
dnf install package.rpmUsing the DNF package manager to install package software.
apt install packageUsing the APT package manager to install package software.
rpm -e package.rpmUsing the RPM package manager to remove or uninstall an rpm package

Search Commands

Commands Description For example
grep pattern fileTo search the contents of a file with a pattern[vagrant@localhost ~]$ grep devopsroles devopsroles.com
welocome devopsroles.com
grep -r pattern directory_nameRecursively or repeatedly searches within a specified directory for a defined pattern match.
find /path/to/folder -name match-asearch based on a character match. In this case [ match-a ][vagrant@localhost ~]$ find /home/vagrant -name devopsroles.com
/home/vagrant/devopsroles.com
find /path/to/folder -name ‘prefix*’Traces a specified system path for files with a matching prefix.[vagrant@localhost ~]$ find /home/vagrant -name ‘devops*’
/home/vagrant/devopsroles.com

SSH Logins

Commands Description For example
ssh user_name@hostnameConnects you to a remote machine or server
ssh hostConnects you to a specified host through the default port 22.
ssh -p port user_name@hostnameConnects you to a remote machine or server through a specified port.
telnet hostnameUses telnet’s default port 23 to connect you to a target hostname, remote machine, or server.

File Transfers and Management

Commands Description For example
rm -r -fTo remove or delete active files and directories
du -sGive important information regarding the disk usage (storage space) on your Linux system. [vagrant@localhost ~]$ du -s /home/vagrant
60 /home/vagrant
file -b -iHelps identify the type of file on your system.[vagrant@localhost ~]$ file -b -i .env
text/plain; charset=us-ascii
mv -f -iUsed for moving directories or files to a different system path or location.
grep, egrep, fgrep -i -vUseful in printing lines with a matching pattern.
scp file.txt server:/tmpTo copy files to a remote server.
scp server:/home/vagrant/*.txt /tmpto copy files from a remote server to a directory on a local machine.
scp -r server:/home/vagrant /tmprecursively copy all the files and directories on a remote server’s directory to a target machine directory.
rsync -a /var/www /backups/Synchronizes the content of two directories (/var/www and /backups) on the same machine.
rsync -avz /home/vagrant server:/backups/synchronizes the content of a folder on a local machine with the content of a folder on a remote server.

File and Directory Commands

Commands Description
lslist the files and directories under and directory path.
pwdprint working directory
mkdir dir_namecreate a directory with the specified name.
rm filenamedelete a file with the specified name.
rm -rf directory_namerecursively and forcefully delete a directory with the specified name.
cp filename1 filename2copy filename1 to filename2
cp -r directory1 directory2recursively copy the content of directory1 to directory2
mv filename1 filename2rename filename1 to filename2
ln -s /path/to/file_name link_nameTo create a symbolic link (link_name) to a specified file name (file_name).
touch filenameto create a new file
more filenameopen and display the contents of a specified file.
cat filenameopen and display the contents of a specified file.
cat filename1 >> filename2appends or adds the content of filename1 at the bottom of filename2.
head filenameOutputs the first ten lines of a specified file name.
tail filenameOutputs the last ten lines of a specified file name.
gpg -c filenameto encrypt a specified file.
gpg filename.gpgto decrypt a specified file with a .gpg extension.
wc filenameOutputs the number of bytes, lines, and words of a specified file name.
cdTakes you to the Home directory
cd /target/directoryTo change directories to a specific directory name.

Disk Utilities and Usage

Commands Description For example
df -hDisplay the amount of free space in the file system[vagrant@localhost ~]$ df -h
Filesystem Size Used Avail Use% Mounted on
devtmpfs 237M 0 237M 0% /dev
tmpfs 244M 0 244M 0% /dev/shm
tmpfs 244M 4.5M 240M 2% /run
tmpfs 244M 0 244M 0% /sys/fs/cgroup
/dev/sda1 40G 4.2G 36G 11% /
tmpfs 49M 0 49M 0% /run/user/1000
df -iWorks with mounted systems to reveal their free inodes.[vagrant@localhost ~]$ df -i
Filesystem Inodes IUsed IFree IUse% Mounted on
devtmpfs 60456 306 60150 1% /dev
tmpfs 62335 1 62334 1% /dev/shm
tmpfs 62335 395 61940 1% /run
tmpfs 62335 16 62319 1% /sys/fs/cgroup
/dev/sda1 20971008 48415 20922593 1% /
tmpfs 62335 1 62334 1% /run/user/1000
fdisk -lprint partition tables of all devices[vagrant@localhost ~]$ sudo fdisk -l
Disk /dev/sda: 42.9 GB, 42949672960 bytes, 83886080 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk label type: dos
Disk identifier: 0x0009ef1a
Device Boot Start End Blocks Id System
/dev/sda1 * 2048 83886079 41942016 83 Linux
du -ahOutputs files and directories disk usage.[vagrant@localhost ~]$ du -ah
4.0K ./.bash_logout
4.0K ./.bash_profile
4.0K ./.bashrc
4.0K ./.ssh/authorized_keys
4.0K ./.ssh/known_hosts
8.0K ./.ssh
0 ./share
4.0K ./.env
8.0K ./.bash_history
4.0K ./devopsroles.com
4.0K ./myscript_onLocal.sh
12K ./share.tar
4.0K ./archive.tar.bz2
4.0K ./share.zip
4.0K ./linuxopratingsystem.net
4.0K ./.viminfo
68K .
findmntOutputs the target mount point associated with all your file systems.
mount device_path mount_pointto mount a device.
mkfs -t -Vto create a new file system.
resize2fsupdating a file system, especially after lvextend*
fsck -A -N to check and repair a file system.
pvcreate creating a physical volume.
mount -a -tmounting a file system.
lvcreatecreating a logical volume.
unmount -f -vunmounting a mounted file system.

Environment Variables

Commands Description For example
envDisplay all exported environment or run a program in a modified environmentvagrant@devopsroles:~$ env
SHELL=/bin/bash
PWD=/home/vagrant
LOGNAME=vagrant
XDG_SESSION_TYPE=tty
MOTD_SHOWN=pam
HOME=/home/vagrant
LANG=en_US.UTF-8
…..
variable_name=variable_valueto assign a variable name with a variable value.vagrant@devopsroles:~$ site=devopsroles.com
vagrant@devopsroles:~$ echo $site
devopsroles.com
echo $Variable_nameOutputs the value of a defined variable on the terminal. vagrant@devopsroles:~$ echo $site
devopsroles.com
export Variable = value To assign an environment variable a new value.vagrant@devopsroles:~$ export site=devopsroles.com
vagrant@devopsroles:~$ env | grep site
site=devopsroles.com
unsetTo remove a variable.vagrant@devopsroles:~$ unset site
vagrant@devopsroles:~$ echo $site

System Processes Management

Commands Description For example
topOutputs all active processes details.
bgrunning process to execute in the background.
fgSends a stopped or halted process to keep executing on the foreground.
ps -efOutputs all active or executing processes on the Linux system.
ps PIDOutputs a running processes’ status in reference to its process ID.
pidoffind the process ID of the running program
kill PIDKills a running process 
nicelets you run a command at a priority lower than the command’s normal priority
renicealters the nice value of one or more running processes
sensorsOutputs the Linux system’s CPU temperature.
ps auxTo monitor processes running on your Linux system
dmesg -kHelps in troubleshooting the health status of your Linux system.
program &Executes a program in the system background.
fg nMoves a running job n to the system’s foreground.

File Editors

Commands Description
vithe editor is a full-screen editor and has two modes of operation
nanothe GNU nano editor.
viewan editor in view or read-only mode.
emacsemacs is a screen editor
sedlaunches stream editor

File Utilities

Commands Description
cut removes or deletes a file’s section.
diff Command to compare files line by line.
head prints the first lines (10 lines by default) of one or more files or piped data to standard output.
joinmerges the lines of two sorted text files based on the presence of a common field.
more, lessto view the contents of a file, a single file page view at a time.
sort to sort a file, arranging the records in a particular order.
splitused to split large files into smaller files.
tr translating or deleting characters.
uniq reports or filters out the repeated lines in a file.
commcompare two sorted files line by line and write to standard output

Performance Monitoring and Statistics

Commands Description
tcpdump -i eth1 ‘port 80’monitoring traffic through port 80
tcpdump -i eth1An interface eth1-related command for outputting captured packets.
watch df -hA command to output periodic system updates.
lsof -u userOutputs a list of all the files opened by a system user.
iostat 1used to get reports and statistics.
vmstat 1Outputs statistical data related to the system’s virtual memory.
mpstat 1Outputs processor-related statistics.

Conclusion

Linux commands cheat sheet a top. I hope will this your helpful. Thank you for reading the DevopsRoles page!

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About HuuPV

My name is Huu. I love technology and especially Devops Skill such as Docker, vagrant, git so forth. I likes open-sources. so I created DevopsRoles.com site to share the knowledge that I have learned. My Job: IT system administrator. Hobbies: summoners war game, gossip.
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