apt-get
Definition: Advanced Package Tool (APT) is a package management system used to install, update, and remove software packages on Debian-based systems.
Example: sudo apt-get update
awk
Definition: A versatile programming language for pattern scanning and text processing. Often used for data extraction and reporting.
Example: cat file.txt | awk '{print $1}'
cat
Definition: Concatenates and displays the content of files. It is often used to display the contents of a file to the terminal.
Example: cat file.txt
cd
Definition: Changes the current working directory to the specified location.
Example: cd /path/to/directory
chmod
Definition: Changes the permissions of a file or directory.
Example: chmod 755 file.sh
chown
Definition: Changes the owner and group of a file or directory.
Example: chown user:group file.txt
cp
Definition: Copies files or directories from one location to another.
Example: cp sourcefile destination
curl
Definition: A command-line tool for transferring data with URLs. It supports a wide range of protocols.
Example: curl -O https://example.com/file.txt
df
Definition: Displays information about disk space usage on the file system.
Example: df -h
du
Definition: Estimates file space usage, showing the sizes of directories and their contents.
Example: du -sh /path/to/directory
echo
Definition: Displays a specified message or variable to the terminal.
Example: echo "Hello, World!"
find
Definition: Searches for files and directories in a directory hierarchy based on specified criteria.
Example: find /path/to/search -name filename
grep
Definition: Searches for patterns in files, printing lines that match the specified criteria.
Example: grep "pattern" file.txt
gzip
Definition: Compresses or decompresses files. It is commonly used to reduce file size.
Example: gzip file.txt
head
Definition: Displays the first few lines of a file.
Example: head -n 5 file.txt
hostname
Definition: Displays or sets the system's host name.
Example: hostname
kill
Definition: Sends a signal to a process, terminating it. The -9 option forces the process to exit.
Example: kill -9 process_id
less
Definition: Allows viewing files one screen at a time, providing convenient navigation.
Example: less file.txt
ls
Definition: Lists files and directories in the current directory.
Example: ls -l
man
Definition: Displays the manual or documentation for a specified command.
Example: man command
mkdir
Definition: Creates a new directory.
Example: mkdir new_directory
mv
Definition: Moves or renames files and directories.
Example: mv oldfile.txt new_location/
nano
Definition: A simple text editor for the command line.
Example: nano file.txt
netstat
Definition: Displays network connections, routing tables, interface statistics, masquerade connections, etc.
Example: netstat -an
ps
Definition: Displays information about processes running on the system.
Example: ps aux
pwd
Definition: Prints the current working directory.
Example: pwd
rm
Definition: Removes or deletes files and directories.
Example: rm file.txt
rmdir
Definition: Removes an empty directory.
Example: rmdir empty_directory
rsync
Definition: Syncs files and directories between two locations while minimizing data transfer.
Example: rsync -av source/ destination/
scp
Definition: Securely copies files between hosts over an SSH connection.
Example: scp file.txt user@remote:/path/to/destination/
sed
Definition: Stream editor for filtering and transforming text.
Example: sed 's/old/new/' file.txt
service
Definition: Used to control services on the system, such as starting or stopping a service.
Example: sudo service apache2 restart
sort
Definition: Sorts lines of text files.
Example: sort file.txt
ssh
Definition: Connects to a remote server using the secure shell protocol.
Example: ssh user@hostname
systemctl
Definition: Controls and manages the systemd system and service manager.
Example: sudo systemctl start service
tail
Definition: Displays the last few lines of a file.
Example: tail -n 10 file.txt
tar
Definition: Creates compressed or uncompressed archive files.
Example: tar -cvzf archive.tar.gz directory/
top
Definition: Displays real-time information about system resource usage.
Example: top
touch
Definition: Creates an empty file or updates the access and modification times of an existing file.
Example: touch newfile.txt
uname
Definition: Prints system information such as the kernel name, version, and machine.
Example: uname -a
uniq
Definition: Filters out repeated lines in a sorted file.
Example: uniq file.txt
uptime
Definition: Displays how long the system has been running and the current system load.
Example: uptime
useradd
Definition: Adds a new user account to the system.
Example: sudo useradd newuser
usermod
Definition: Modifies an existing user account, including group membership.
Example: sudo usermod -aG groupname username
vi
Definition: A text editor with both command and insert modes.
Example: vi filename
wc
Definition: Counts the number of lines, words, and characters in a file.
Example: wc -l file.txt
wget
Definition: Retrieves files from the internet using the HTTP, HTTPS, or FTP protocols.
Example: wget https://example.com/file.txt
whereis
Definition: Locates the binary, source, and manual page files for a command.
Example: whereis command
which
Definition: Shows the full path of the executable related to the provided command.
Example: which command
zip
Definition: Compresses files into a zip archive.
Example: zip -r archive.zip directory/