A guide to Ubuntu Linux Terminal Commands for your Dell PC

A guide to Ubuntu Linux Terminal Commands for your Dell PC



This article provides information on the terminal applications commands in Ubuntu Linux.


Table of Contents:

  1. Basic Control Commands
  2. Basic User and System Commands
  3. Basic Drives and Rights Commands
  4. Basic Network Commands

1. Basic Control Commands

Terminal Commands are a set of instructions you can use while in the Ubuntu terminal application to accomplish any tasks on your system. I've subdivided the commands into smaller tables to make their uses more clear and to aid in using these articles as a reference point.

Command Effect Additional Info
cd Change Directory with this command you can navigate
through the system. simply typing
'cd' or 'cd~' will take you to the
home folder, which is the default
starting position in terminal.
cd/ Go to root directory
cd.. Up one directory level
cd- Back to previous directory
pwd Print working directory this displays your location in the system.
bash GNU Bourne-again shell
break Exit from a loop
case Conditionally perform a command
clear Clear terminal screen
continue Resume the next iteration of a loop
cron Daemon to execute scheduled commands
crontab Schedule a command to run at a later time
echo Display message on screen
enable Enable and disable builtin shell commands
env Environment Variables
eval Evaluate several commands/arguments
expect Automate applications accessed over a terminal
export Set an environment variable
expr Evaluate expressions
false Do nothing, unsuccessfully
for Expand words and execute commands
hash Remember the full pathname of a name argument
hostname Print or set system name
if Conditionally perform a command
jobs List active jobs
join Join lines on a common field
local Create variables
logout Exit a login shell
more Display output one screen at a time
nice Set the priority of a command or job
nohup Run a command immune to hangups
notify-send Send desktop notifications
op Operator access
readarray Read from stdin into an array variable
readonly Mark variables/functions as readonly
reboot Reboot the system
return Exit a shell function
sed Stream editor
select Accept keyboard input
set Manipulates shell variables and functions
shift Shift positional parameters
shopt shell options
shutdown Shutdown or restart Linux
sleep Delay for a specified time
ssh Secure shell client remote login program
suspend Suspend execution of this shell
sync Synchronise data on disk with memory
test Evaluate a conditional expression
trap Run a command when a signal is set
true Do nothing, successfully
type Describe a command
unshar Unpack shell scripts
until Execute commands until error
vmstat Report virtual memory statistics
watch Execute/display a program periodically
while Executes commands
write Send a message to another user
xargs Execute utility, passing constructed argument lists
### Allows you to remark/comment without disturbing the terminal
while Executes commands

Managing files and text are commands that directly affect the files and the text that are stored and used on your computer. The Dash and the Windows Explorer tool are well known Graphical User Interface GUI versions of this tool.

Command Effect Additional Info
cp Copy allows you to copy a file, to do so add the name of the file you want to copy along with the command. as long as the file is located in the directory you've browsed to. otherwise tpye 'cp~/< file path >' in order to specify where the file you wanted to copy is located.
ls List Lists all the files in current directory.
ls~ Lists files in the home directory adding a folder name shows a list of all the files in that specific folder. i.e. 'ls~/desktop' will show you the files in the desktop folder.
mkdir Make directory allows you to create a directory. i.e. mkdir private files, will make a new directory called private files located in the home directory unless you browsed to another directory or specified another path.
mv Move you can rename or move a file with this command. if you want to rename the file 'sunny' to 'day', you may want to type 'mv sunny day'. this requires that you have browsed to the correct directory or that you specified the correct file path. when type 'mv day ~/Desktop', the file 'day' will be moved from home to Desktop, but if you want to rename the file as well, ass the new file name next to the current name in the command.
rm Remove simply removes a file, specify the file path/file name.
rmdir Remove directory removes an 'empty' directory.
rm -r Remove recursively removes a directory along with it's content.
grep Search for text strings
head Display start of file
less Display part of file
tail Display end of file
apropos Search help manual pages
aspell Spell Checker
awk Find and Replace text database sort/validate/index.
cmp Compare two files
comm Compare two sorted files line by line
csplit Split a file into context-determined peices
cut Divide a file into two separate pieces
cksum Print CRC checksum and byte counts
find Search for files that meet set criteria
fmt Format paragraph text
fold Wrap text to specific width
dir Briefly list directory contents
dircolors Colour setup for 'ls'
dirname Convert a full pathname to just a path
dirs Display a list of remembered directories
cat Display the contents of a file
bzip2 Compress or decompress named files
chroot Run a command with a different root directory
fgrep Search files for lines that match a fixed string
fuser Identify/Kill the process that is accessing a file
gawk Find and replace text within files
gzip Compress or decompress Name files
ln Makes links between files
locate Find files
look Display lines beginning with a given string
lpr Off line print
lpc Line printer control program
lprm Remove jobs from the print queue
lprint Print a file
lprintd Abort a print job
lprintq List of the print queue
lsof List open files
vdir Verbosely list directory contents 'ls -| -b'
v Verbosely list directory contents 'ls -| -b'
vi Text editor
uuencode Decode a file decode a file using uuencode.
uuencode Encode a file encode a file using uuencode.
tty Print filename of terminal on stdin
touch Change file timestamps
expand Convert tabs to spaces
import Capture an x server screen and save the image to file
install Copy files and set attributes
fg Send job to foreground
bg Send job to background
nl Number lines and write files
open Open a file in it's default application
paste Merge lines of files
pathchk Check file name portability
popd Restore the previous value of the current directory
pr Prepare files for printing
printcap Printer capability database
printenv Print environment variables
printf Format and print data
pushd Save and then change the current directory
rcp Copy files between two machines
read Read a line from standard input
rename Rename files
remsync Synchronise remote files via email
mmb Mass move and rename files
mtools Manipulate MS-DOS files
rev Reverse lines in a file
rsync Remote copy a file synchronise files trees
sdiff Merge two files interactively
scp Secure copy
sftp Secure file transfer program
slocate Find file
sort Sort text files
split Split a file into fixed size pieces
sum Print a checksum for a file
tee Redirect output to multiple files
tsort Topological sort
unmask User file creation mask
source Run commands from file
symlink Makes a new name for a file
tr Translate, squeeze and/or delete
uniq Uniquify files
wc Print byte, word and line counts
whereis Search the user's $path, man pages and source files for a program
which Search the user's $path for a program file
wget Retrieve web pages or files
unexpand Convert space to tabs
yes Print a string until interrupted
xdg-open Open a file or URL in the user's preferred application
dmesg Print kernel and driver messages


Back to Top


2. Basic User and System Commands

These commands enable you to manage, configure, troubleshoot and reset the User and Group settings on your Ubuntu system.

Command Effect Additional Info
passwd Create a password
groupadd Add a group
groupmod Modify a group
chgrp Change group
groupdel Delete group
adduser Add a user to the system
addgroup Add a group to the system
alias Create an alias
useradd Create a new user account
usermod Modify user account
users List users currently logged in
chmod Change access permissions
chown Change file owner and group
groups Print group names a user is in
id Print user and group id's
logname Print current login name
su Substitute user identity
times User and system times
who Print all usernames currently logged in
whoami Print the current user id and name id -un

The commands below deal with system specific programs and information.

Command Effect Additional Info
cal Calendar display a calendar
date Date display the date
dc Desk Calculator Calculator
fsck File System Check
bc Arbitrary precision calculator language
kill Stop a process from running
killall Kill processes by name
let Perform arithmetic on shell variables
make Recompile a group of programs
pkill Stop processes from running
ps Process status
seq Print numeric sequences
units Convert units from one scale to another

Packages are the Ubuntu default method of loading and updating new applications and files. These commands allow for management and configuration of the packages downloaded.

Command Effect Additional Info
apt -get Search for and Install software packages
aptitude Search for and Install software packages
apt -get update Refresh available updates
apt - get upgrade Upgrade all packages
apt -get dist-upgrade Upgrade with package replacements Upgrade Ubuntu Version
apt -get install pkgname Install package by name
apt -get purge pkgname Uninstall package by name
apt -get autoremove Remove obsolete packages
apt -get -f install Try to fix broken packages
dpkg -configure -a Try to fix broken packages
dpkg -i pkg.deb Install file pkg.deb

These commands give you a direct way to manage the services on your Ubuntu system.

Command Effect Additional Info
start service Start job service Upstart
stop service Stop job service Upstart
status service Check if service is running Upstart
/etc/init.d/service start Start service SysV
/etc/init.d/service stop Stop service SysV
/etc/init.d/service restart Restart service Sysv
/etc/init.d/service check Check service SysV
runlevel Get current runlevel


Back to Top


3. Basic Drives and Rights Commands

Managing the drives and formats simply means that you can affect the peripherals attached to your system. Whether this be multiple Hard disk drives, removable media or other devices. They allow you to manage and configure these devices at the command line level.

Command Effect Additional Info
mount Mount a drive
unmount Unmount a drive
fdisk Format disk
cfdisk Partition table editor for Linux
dd Duplicate disk convert and copy a file, write
disk headers, boot records,
ddrescue Data recovery tool
declare Declare variables and assign attributes
df Disk free space displays how much disk space on
every mounted partition that is
occupied. df uses MB and GB instead
of blocks.
du Directory usage displays how much space a given
directory plus all of it's
subdirectories uses.
du -s Directory usage summary
du -h Directory usage basic info this translates the information into
a basic non-tech format.
free How much free space is available this tells you how much free space
is available for use.
free -m Shows free space statistics shows the statistics in MB.
uname -a Get all kernel information
uname -r Get kernel information
lsb_release -a Prints information about your Linux distro
top Start system monitoring this initiates monitoring, viewing RAM,
CPU and swap usage, plus the
total running processes.
q Stop system monitoring
diff Display difference between 2 files
diff3 Display difference between 3 files
Note: Most of the following commands will need to be prefaced with the sudo command. This elevates privileges to the root-user administrative level temporarily, which is necessary when working with directories or files not owned by your user account. When using sudo you will be prompted for your password. Only users with sudo (administrative) privileges will be able to use this command.
Command Effect Additional Info
history List of all commands user the history command shows a very long list
of commands that you have typed. each
command is displayed next to a number. you
can type | x to execute a previously
typed command from the list (replace the X
with a number). if your history output
is too long, then use history | less
for a scrollable list.
REISUB Reboot system hold down both the ALT and PRINTSCRN keys while
typing this to restart the computer.
apt -get Application used to install, removed, upgrade and more.
file Type checking of one or more files
sleep Delay commands wait x seconds to continue with the next command.
pidof Get PID PID given in readable format
ps System monitor for command line also good for scripts.
cat Print out file in command line
crontab Time drive events
man Help manual open the manual of programs, displays
the command manual.
man man Manual about Manual help page about using help page.
man intro Brief list of commands when you need information about a command
, type "< command name >-h" or "< command name
>--help", if the first rule did not work. You
see some command lines may not associate -h
with --help.
info info Introduction to info pages
basename Strip directory and suffix from filenames
eject Eject removable media
fdformat Low level format format a FD floppy disk.
mkisofs Create a hybrid filesystem
format Format disks or tapes
mknod Make block or character special files
quotactl Set disk quotas
quotacheck Scan a file system for disk usage
quota Display disk usage and limits
tar Tape archiver
ram RAM disk device

The rights to files and directories and the ability to change them are required at an administrator level. These can be used to change or repair existing files or to stop other files or directories from being damaged by inexperienced users.

Command Effect Additional Info
chmod Change Mode
su Switch User
ulimit Limit user resources
unalias Remove an alias
unset Remove variable or function names
function Define Function macros

Elevated privileges is what Ubuntu calls Administrator Rights. You will need to run these commands when you need to change things on your system at a high enough level. The windows equivalent would be opening a command prompt as an administrator.

Command Effect Additional Info
sudo Elevated privileges executing commands with elevated privileges
- < superuser do > a very common expression which
indicates that the taken action must
be verified with the admin password.
sudo -r Open root shell as user
sudo -r -u Open shell as user
sudo -k Forget sudo passwords


Back to Top


4. Basic Network Commands

These commands deal with configuring and troubleshooting Network connections on your system. This includes wired and wireless connections.

Command Effect Additional Info
chkconfig Check activated services
ping Test network connections
ftp File Transfer Protocol
host Check IP of Domain
ifconfig Configure network devices
iwconfig Show wireless information
sudo iwlist scan Scan for wireless networks
ifup eth0 Bring interface eth0 online
ifdown eth0 Display the eth0 interface
netstat Display routing table
route Set routes
telnet Connect to Telnet
traceroute Display route
dig DNS lookup
ethtool Ethernet card settings
mkfifo Make FIFOs named pipes
mtr Network diagnostics traceroute/ping
nslookup Query Internet name servers interactively
screen Multiplex terminal run remote shells via ssh
strace Trace system calls and signals

These commands deal with the Ubuntu firewall management and configuration.

Command Effect Additional Info
ufw enable Turn on firewall
ufw disable Turn off firewall
ufw default allow Allow all connections by default
ufw default deny Deny all connections by default
ufw status Cyrrebt status and rules
ufw allow port Allow traffic on port
ufw deny port Deny traffic on port
ufw deny from ip Block IP Address


Back to Top


Additional Information :

Note :
Software support is provided by Canonical through the following methods:
Technical Support is provided by Dell :


Back to Top





Quick Tips content is self-published by the Dell Support Professionals who resolve issues daily. In order to achieve a speedy publication, Quick Tips may represent only partial solutions or work-arounds that are still in development or pending further proof of successfully resolving an issue. As such Quick Tips have not been reviewed, validated or approved by Dell and should be used with appropriate caution. Dell shall not be liable for any loss, including but not limited to loss of data, loss of profit or loss of revenue, which customers may incur by following any procedure or advice set out in the Quick Tips.

Article ID: SLN265879

Last Date Modified: 08/28/2018 06:49 AM


Rate this article

Accurate
Useful
Easy to understand
Was this article helpful?
Yes No
Send us feedback
Comments cannot contain these special characters: <>()\
Sorry, our feedback system is currently down. Please try again later.

Thank you for your feedback.