Unix Commands

Shortcuts

Command	Description
Navigation
ctrl + A	Move to the beginning of the line
ctrl + E	Move to the end of the line
ctrl + U	Delete from the cursor to the beginning of the line
ctrl + K	Delete from the cursor to the end of the line
ctrl + W	Delete the word to the left of the cursor
ctrl + L	Clear the screen
History
ctrl + R	Search backward in history
ctrl + G	Escape from history searching mode
!!	Repeat the last command
!n	Repeat the nth command in history
!$	Refer to the last argument of the previous command
process management
ctrl + C	Interrupt/kill the current foreground process
ctrl + Z	Suspend the current foreground process
file and directory
tab	Auto-complete file and directory names
ctrl + D	Exit the current shell(or end of input)
miscellaneous
ctrl + S	Stop the output to the screen (XOFF)
ctrl + Q	Resume the output to the screen (XON)
ctrl + T	Swap the last two characters before the cursor
ctrl + Y	Paste the last deleted text
ctrl + _	Undo the last change

Navigation

Command	Description
pwd	Print current working directory.
ls	List files in the current directory.
ls -a	list all files including hidden files
ls -lh	formatted list including more data
ls -t	list sorted by date
cd [directory]	Change directory.
cd ..	Move to the parent directory.
cd /	Move to root directory
cd ~	Move to the home directory.

File Operation

Command	Description
cp [source] [destination]	Copy files/directories.
mv [source] [destination]	Move/rename files/directories.
rm [file]	Remove/delete files.
rm -r [dir]	Delete a directory and its files
mkdir [directory]	Create a new directory.
rmdir [directory]	Remove an empty directory.
touch [file]	Create an empty file.
cat [file]	Display the content of a file.
cat [file1] [file2] > [file3]	Merge files 1 and 2 into file3
more [file] or less [file]	Display content one screen at a time.
less -N [file]	Include line numbers
less -S [file]	Wrap long lines
man {command}	Display commands manual
apt-get install	Install applications in linux
head [file]	Display the first few lines of a file.
head -n 5 [file]	Display first five lines from a file
tail [file]	Display the last few lines of a file.
tail -n 5 [file]	Display last five lines from a file.

Text Handling

Command	Description
echo [message]	Display a message.
grep [pattern] [file]	Search for a pattern in files.
sed 's/pattern/replacement/' [file]	Stream Editor for text replacement.
awk '{print $1}' [file]	Text processing and pattern matching.
sort [file]	Sort lines of text files.
uniq [file]	Remove duplicate lines from a sorted file.
cut -f [fields] [file]	Remove sections from each line of a file.
tr 'A-Z' 'a-z' < [file]	Translate or delete characters.
wc [file]	Count lines, words, and characters in a file.
paste file1 file2	Merge lines of files.
comm file1 file2	Compare two sorted files line by line.
tee file1 file2	Redirect output to multiple files.
fmt [file]	Reformat paragraph text.
nano [file]	A simple text editor
vim [file]	A powerful text editor

Compression

Command	Description
tar -cvf archive.tar [files/directories]	Create a tar archive.
gzip [file]	Compress a file using gzip.
gunzip [file.gz]	Decompress a gzip-compressed file.
bzip2 [file]	Compress a file using bzip2.
bunzip2 [file.bz2]	Decompress a bzip2-compressed file.
xz [file]	Compress a file using xz.
unxz [file.xz]	Decompress an xz-compressed file.
zip [archive.zip] [files/directories]	Create a zip archive.
unzip [archive.zip]	Extract files from a zip archive.

Networking

Command	Description
ping [hostname or IP]	Test network connectivity.
traceroute [hostname or IP]	Display the route packets take to reach a destination.
wget [url]	Download a file from an url
wget -c [url]	Continue a stopped download
nslookup [hostname or IP]	Query DNS information.
dig [hostname or IP]	DNS lookup utility.
ifconfig or ip a	Display network interfaces.
netstat or ss	Display network connections.
ssh [user@]hostname	Connect to a remote server securely.
scp [file] [user@]hostname:[destination]	Securely copy files between hosts.
telnet [hostname or IP] [port]	User interface to the TELNET protocol.
hostname	Display or set the system’s host name
nc [hostname or IP] [port]	Netcat - TCP/IP Swiss Army knife.
route	Display or manipulate the IP routing table
curl {url}	A command-line tool for making HTTP requests
iptables {options}	Tool to manage kernel Netfilter firewall rules

Process Management

Command	Description
ps	Display your currently active processes
ps aux	Display information about running processes.
top or htop	Display real-time system information and processes.
kill [PID]	Terminate a process.
killall [process_name]	Terminate all processes with a specific name.
pkill [process_name]	Terminate processes based on their name.
nice [command]	Run a command with modified scheduling priority.
renice [priority] [PID]	Change the priority of a running process.
pgrep [process_name]	Return process IDs based on their name.
pmap [PID]	Display the memory map of a process.
pstree	Display running processes in a tree-like structure.
jobs	List background jobs in the current shell session.
bg [job_number]	Put a suspended job in the background.
fg [job_number]	Bring a background job to the foreground.

Searching

Command	Description
find [directory] -name [filename]	Search for files and directories.
grep [pattern] [file]	Search for a pattern in files.
locate [filename]	Quickly find the location of files.
which [command]	Show the full path of an executable.
whereis [command]	Locate the binary, source, and manual page files.
ag [pattern] [directory]	A faster code searching tool.
rg [pattern] [directory]	A line-oriented search tool.
grep -r [pattern] [directory]	Recursively search for a pattern in files.
find [directory] -exec [command] {} \;	Find files by name and execute a command on each file.
grep -i [pattern] [file]	Search for a pattern in a case-insensitive manner.
grep -n [pattern] [file]	Show line numbers along with matching lines.
grep -A 2 -B 2 [pattern] [file]	Display lines of context around matching lines.

System Information

Command	Description
date	Display the current date and time
cal	Display this month’s calendar
uname -a	Display system information.
hostname	Display the system hostname.
lsb_release -a	Display distribution-specific information.
top or htop	Display real-time system information and processes.
w	Display who is online
whoami	Who you are logged in as
finger {user}	Display information about user
uname -a	Display kernel information
free -m	Display memory usage.
df -h	Display disk space usage.
uptime	Display system uptime and load average.
ifconfig or ip a	Display network interfaces.
dmesg	Display kernel ring buffer.
lshw	Display detailed hardware configuration.
lscpu	Display CPU information.
lsusb	Display USB devices.
lspci	Display PCI devices.