Linux command from basic to advance for beginners
a
apropos- Search Help manual pages (man -k)
apt-get- Search for and install software packages (Debian/Ubuntu)
aptitude- Search for and install software packages (Debian/Ubuntu)
aspell- Spell Checker
awk -Find and Replace text, database sort/validate/index
b
basename- Strip directory and suffix from filenames
bash- GNU Bourne-Again SHell
bc -Arbitrary precision calculator language
bg- Send to background
break- Exit from a loop •
builtin- Run a shell builtin
bzip2- Compress or decompress named file(s)
c
cal- Display a calendar
case- Conditionally perform a command
cat- Concatenate and print (display) the content of files
cd- Change Directory
cfdisk -Partition table manipulator for Linux
chgrp -Change group ownership
chmod- Change access permissions
chown- Change file owner and group
chroot- Run a command with a different root directory
chkconfig- System services (runlevel)
cksum- Print CRC checksum and byte counts
clear- Clear terminal screen
cmp- Compare two files
comm- Compare two sorted files line by line
command- Run a command - ignoring shell functions •
continue- Resume the next iteration of a loop •
cp -Copy one or more files to another location
cron- Daemon to execute scheduled commands
crontab- Schedule a command to run at a later time
csplit- Split a file into context-determined pieces
cut -Divide a file into several parts
d
date- Display or change the date & time
dc- Desk Calculator
dd- Convert and copy a file, write disk headers, boot records
ddrescue- Data recovery tool
declare- Declare variables and give them attributes •
df -Display free disk space
diff -Display the differences between two files
diff3- Show differences among three files
dig- DNS lookup
dir- Briefly list directory contents
dircolors- Colour setup for `ls'
dirname- Convert a full pathname to just a path
dirs- Display list of remembered directories
dmesg- Print kernel & driver messages
du- Estimate file space usage
e
echo -Display message on screen •
egrep -Search file(s) for lines that match an extended expression
eject- Eject removable media
enable -Enable and disable builtin shell commands •
env- Environment variables
ethtool- Ethernet card settings
eval- Evaluate several commands/arguments
exec- Execute a command
exit- Exit the shell
expect -Automate arbitrary applications accessed over a terminal
expand- Convert tabs to spaces
export -Set an environment variable
expr- Evaluate expressions
f
false- Do nothing, unsuccessfully
fdformat- Low-level format a floppy disk
fdisk- Partition table manipulator for Linux
fg- Send job to foreground
fgrep- Search file(s) for lines that match a fixed string
file- Determine file type
find- Search for files that meet a desired criteria
fmt- Reformat paragraph text
fold- Wrap text to fit a specified width.
for- Expand words, and execute commands
format- Format disks or tapes
free- Display memory usage
fsck File system consistency check and repair
ftp File Transfer Protocol
function Define Function Macros
fuser Identify/kill the process that is accessing a file
g
gawk- Find and Replace text within file(s)
getopts -Parse positional parameters
grep- Search file(s) for lines that match a given pattern
groupadd- Add a user security group
groupdel -Delete a group
groupmod- Modify a group
groups- Print group names a user is in
gzip- Compress or decompress named file(s)
h
hash- Remember the full pathname of a name argument
head- Output the first part of file(s)
help- Display help for a built-in command •
history -Command History
hostname- Print or set system name
i
iconv- Convert the character set of a file
id- Print user and group id's
if- Conditionally perform a command
ifconfig- Configure a network interface
ifdown- Stop a network interface
ifup- Start a network interface up
import- Capture an X server screen and save the image to file
install- Copy files and set attributes
j
jobs- List active jobs •
join- Join lines on a common field
k
kill- Stop a process from running
killall- Kill processes by name
l
less- Display output one screen at a time
let- Perform arithmetic on shell variables •
ln -Create a symbolic link to a file
local- Create variables •
locate- Find files
logname- Print current login name
logout -Exit a login shell •
look- Display lines beginning with a given string
lpc- Line printer control program
lpr- Off line print
lprint- Print a file
lprintd- Abort a print job
lprintq- List the print queue
lprm- Remove jobs from the print queue
ls- List information about file(s)
lsof- List open files
m
make Recompile a group of programs
man Help manual
mkdir Create new folder(s)
mkfifo- Make FIFOs (named pipes)
mkisofs- Create an hybrid ISO9660/JOLIET/HFS filesystem
mknod- Make block or character special files
more- Display output one screen at a time
mount -Mount a file system
mtools- Manipulate MS-DOS files
mt-r Network diagnostics (traceroute/ping)
mv- Move or rename files or directories
mmv- Mass Move and rename (files)
n
netstat- Networking information
nice- Set the priority of a command or job
nl- Number lines and write files
nohup- Run a command immune to hangups
notify-send Send desktop notifications
nslookup- Query Internet name servers interactively
o
open- Open a file in its default application
op- Operator access
p
passwd- Modify a user password
paste- Merge lines of files
pathchk- Check file name portability
ping- Test a network connection
pkill -Stop processes from running
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 •
ps- Process status
pushd -Save and then change the current directory
pwd- Print Working Directory
q
quota- Display disk usage and limits
quotacheck- Scan a file system for disk usage
quotactl- Set disk quotas
r
ram ram disk device
rcp -Copy files between two machines
read- Read a line from standard input •
readarray- Read from stdin into an array variable •
readonly -Mark variables/functions as readonly
reboot- Reboot the system
rename- Rename files
renice- Alter priority of running processes
remsync- Synchronize remote files via email
return- Exit a shell function
rev -Reverse lines of a file
rm- Remove files
rmdir- Remove folder(s)
rsync- Remote file copy (Synchronize file trees)
s
screen -Multiplex terminal, run remote shells via ssh
scp- Secure copy (remote file copy)
sdiff- Merge two files interactively
sed- Stream Editor
select- Accept keyboard input
seq- Print numeric sequences
set- Manipulate shell variables and functions
sftp -Secure File Transfer Program
shift- Shift positional parameters
shopt- Shell Options
shutdown- Shutdown or restart linux
sleep- Delay for a specified time
slocate- Find files
sort- Sort text files
source- Run commands from a file `.'
split- Split a file into fixed-size pieces
ssh- Secure Shell client (remote login program)
strace -Trace system calls and signals
su- Substitute user identity
sudo- Execute a command as another user
sum- Print a checksum for a file
suspend- Suspend execution of this shell •
symlink- Make a new name for a file
sync- Synchronize data on disk with memory
t
tail- Output the last part of file
tar- Tape ARchiver
tee- Redirect output to multiple files
test- Evaluate a conditional expression
time- Measure Program running time
times- User and system times
touch- Change file timestamps
top- List processes running on the system
traceroute- Trace Route to Host
trap -Run a command when a signal is set(bourne)
tr -Translate, squeeze, and/or delete characters
true- Do nothing, successfully
tsort- Topological sort
tty -Print filename of terminal on stdin
type- Describe a command •
u
ulimit- Limit user resources •
umask- Users file creation mask
umount -Unmount a device
unalias -Remove an alias •
uname -Print system information
unexpand- Convert spaces to tabs
uniq Uniquify- files
units -Convert units from one scale to another
unset- Remove variable or function names
unshar -Unpack shell archive scripts
until Execute commands (until error)
uptime -Show uptime
useradd- Create new user account
userdel- Delete a user account
usermod- Modify user account
users- List users currently logged in
uuencode -Encode a binary file
uudecode- Decode a file created by uuencode
v
v- Verbosely list directory contents (`ls -l -b')
vdir- Verbosely list directory contents (`ls -l -b')
vi -Text Editor
vmstat- Report virtual memory statistics
w
wait Wait for a process to complete •
watch- Execute/display a program periodically
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
while- Execute commands
who- Print all usernames currently logged in
whoami- Print the current user id and name (`id -un')
wget -Retrieve web pages or files via HTTP, HTTPS or FTP
write -Send a message to another user
x
xargs- Execute utility, passing constructed argument list(s)
xdg-open- Open a file or URL in the user's preferred application.
