Commands and Utilities
AWK
Specified Programming Language, which we could use for easy scripts
$1
First column,
$0
All columns
$NF
Last colums
awk '{print $1}'
Output of the first column
OFS="/"
Change separator to /
BEGIN {print "Kek"}
Before the main command, display Kek
-F:
We show that the string uses a separator: :
$3 >= 1000
The value of the third column is less than more than 1000
/UUID/
Look for UUID pattern
/^UUID/
Look for pattern which begins with UUID
TEE
Command for Redirecting Output in Linux
command
tee file`
command
tee -a file
tee file1 file2
Redirect output to multiple files simultaneously
tee -a file1 file2
Append output to multiple files simultaneously
echo "Text" | tee file
Display and save "Text" to file
command1 | tee > (command2)
Pipe output of command1 to command2 and display on the terminal
command | tee /dev/tty
Display output on the terminal, but not redirect to a file
SUDO
Linux utility that provides the ability to execute commands with different levels of access, including root
sudo -l
Check privileges
sudo -u
Do smth on behalf of the user
sudo su
Change to root user
sudo
Do smth on behalf of root user
LESS
If the file is very large, this utility does not allow you to clog up the entire term of the terminal, that is, it shortens the output and allows you to scroll up and down
less -F
Monitor changes in the file
less -X
Leave what was in the file without deleting it after disabling the command
less -N
Number lines
TAIL
Command used to output the contents of a file, usually at the end of that file
tail -50
Lines, need to be taken from the end
tail +50
Lines, need to be taken from the beginning
tail -c
Number of bytes to be removed from the end
tail -F
Look for changes in a file
WGET
Download files from sites
wget IP
Download the file from the site
wget -O
Download the file under a new name
wget -i
Download a file from the list
GREP
Linux command used to search for text strings in files or other commands output
grep "text" file.txt
Find text in a file
grep -i
Search regardless of case
grep "text" file1.txt file2.txt
Search in two files
grep -r "text" documents/ -e "*.txt"
Search in the documents directory only in .txt files
grep -r "text"
Search in local directories and subdirectories
SCP
Linux command, which is used to securely copy files and directories from one computer to another over a network
scp username@remote_server:/full/path/to/remote_file /local/path/to/local_directory/
From remote to local
scp /local/path/to/local_file username@remote_server:/remote/path/to/destination/
From local to remote
FIND
Linux command used to search for various information in the file system
.
Current directory
./kek
Relative directory
/home/carnifex17/kek
Absolute path to the directory
find ./GFG -perm 664
Search for files with permissions 664 in the .GFG directory
-name
File name
-type f
This option specifies that only files are searched.
-type d
Only directories are being searched.
find . -type f -mtime -3
Used to search for files by their modification time The file was modified less than 3 days ago
PS
A program for Linux that is designed to search for various system processes
ps aux
All processes
ps -p PID
Additional info about PID
ps -u shrek
Additional info from shrek user
CHOWN
A command in the Linux operating system that is used to change the owner or group of a file or directory
chown owner_name file_name
Change owner
chown :group1 file1.txt
Change group of file
chown master:group1 file1.txt
Change both
chown --reference=greek1 greek2
Use greek1 rights as reference
NSLOOKUP
An operating system command used to perform DNS queries and obtain information about domain names, IP addresses, and other DNS records.
nslookup -type=any
List all available DNS records
nslookup -type={type of dns recording}
Search for certain DNS record
A, MX, NS, TXT, SOA, AAAA, CNAME
Types of DNS records
DIG
Younger sibling of nslookup
dig site.com +short
A record
dig site.com +nocomments
No comments
dig site.com ANY
All records
dig site.com +trace
Trace DNS path
UNAME
A command in the Unix operating system and similar systems that displays information about the system and its kernel.
uname -a
All system info
uname -s
Kernel name
uname -r
Kernel release date
UNIQ
Linux command which looks for repeatings strings and helps to manage them
uniq -c
Counts how many times it is repeated
uniq -d
Only displays repeated feeds
uniq -u
Displays unique feeds
SORT
You will never guess what it does
sort -o outputfile.txt inputfile.txt
Sorting with output to a specified file
sort -r
Sorting in reverse order
sort -n
Sorting by numbers
sort -nr
Sorting by numbers in reverse order
sort -k 2n file.txt
Sort by second column by numbers
WHOIS
Command Linux, which looks for info about domains
whois site.com
Displaying information by domain name
whois 125.8.888.200
Displaying information by IP address
TAR
Linux command used to unzip tar format
tar -xvf file.tar
Detailed unzipping
SYSTEMCTL
Linux command to manage different services
sudo systemctl restart service
Restart service
sudo systemctl status service
Check service status
sudo systemctl stop service
Stop service
sudo systemctl --type=service --state=running
List active service
NETCAT
Universal utility for network connection in Unix and similar operating systems
nc host port
Connects to the host on the specified port
nc -l -p port
Starts nc in listener mode on the specified port
nc -z host {port-range}
Basic port scanner
nc -v host port
Get banner
nc -l -p local_port -c 'nc remote_host remote_port'
Configures a basic proxy where it listens for a specific local port and forwards it to a remote server
nc -l -p 1234 -e /bin/bash
Simple backdoor
IP
Linux command to manage ІР. Older brother of ifconfig
ip addr
Shows all addresses
ip -4 addr
Shows IPv4 address
ip -6 addr
Shows IPv6 address
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