Description: List directory contents
Usage: ls [options] [file]
Example: ls -l /home/user
Description: Change the shell working directory
Usage: cd [directory]
Example: cd /var/log
Description: Make directories
Usage: mkdir [options] directory
Example: mkdir new_folder
Description: Remove files or directories
Usage: rm [options] file
Example: rm -r my_folder
Description: Copy files and directories
Usage: cp [options] source destination
Example: cp file1.txt file2.txt
Description: Move (rename) files
Usage: mv [options] source destination
Example: mv oldname.txt newname.txt
Description: Concatenate and display file content
Usage: cat [options] file
Example: cat myfile.txt
Description: Display a line of text
Usage: echo [options] string
Example: echo "Hello, World!"
Description: Search for files in a directory hierarchy
Usage: find [path] [expression]
Example: find /home -name "*.txt"
Description: Print lines matching a pattern
Usage: grep [options] pattern [file]
Example: grep "hello" myfile.txt
Description: Change file modes or Access Control Lists
Usage: chmod [options] mode file
Example: chmod 755 script.sh
Description: Change file owner and group
Usage: chown [options] owner[:group] file
Example: chown user:group myfile.txt
Description: Report a snapshot of current processes
Usage: ps [options]
Example: ps aux
Description: Send a signal to a process
Usage: kill [options] pid
Example: kill -9 1234
Description: Display Linux tasks
Usage: top
Example: top
Description: Report file system disk space usage
Usage: df [options]
Example: df -h
Description: Convert and copy a file
Usage: dd [options]
Example: dd if=/dev/zero of=testfile bs=1M count=10
Description: Estimate file space usage
Usage: du [options] [file]
Example: du -sh *
Description: An interface to the system reference manuals
Usage: man [command]
Example: man ls
Description: Execute a command as another user
Usage: sudo [command]
Example: sudo apt-get update
Description: OpenSSH remote login client
Usage: ssh [options] [user@]hostname
Example: ssh [email protected]
Description: Secure copy (remote file copy program)
Usage: scp [options] [[user@]host1:]file1 ... [[user@]host2:]file2
Example: scp file.txt [email protected]:/path/to/destination
Description: Transfer a URL
Usage: curl [options] [URL]
Example: curl -O http://example.com/file.txt
Description: The non-interactive network downloader
Usage: wget [options] [URL]
Example: wget http://example.com/file.txt
Description: Send ICMP ECHO_REQUEST to network hosts
Usage: ping [options] destination
Example: ping google.com
Description: Print the route packets take to the network host
Usage: traceroute [options] host
Example: traceroute google.com
Description: Print network connections, routing tables, interface statistics, masquerade connections, and multicast memberships
Usage: netstat [options]
Example: netstat -tuln
Description: Configure a network interface
Usage: ifconfig [interface]
Example: ifconfig eth0
Description: Administration tool for IPv4 packet filtering and NAT
Usage: iptables [options]
Example: iptables -L
Description: An archiving utility
Usage: tar [options] [archive-file] [file or directory]
Example: tar -czvf archive.tar.gz /path/to/dir
Description: Compress files
Usage: gzip [options] [file]
Example: gzip file.txt
Description: Decompress files
Usage: gunzip [options] [file]
Example: gunzip file.txt.gz
Description: Package and compress (archive) files
Usage: zip [options] [archive file] [file or directory]
Example: zip -r archive.zip /path/to/dir
Description: List, test, and extract compressed files in a ZIP archive
Usage: unzip [options] [zipfile]
Example: unzip archive.zip
Description: Show or set the system's hostname
Usage: hostname [options] [new_hostname]
Example: hostname
Description: Tell how long the system has been running
Usage: uptime
Example: uptime
Description: Print the current user id and name
Usage: whoami
Example: whoami
Description: Update a user's authentication tokens
Usage: passwd [options] [username]
Example: passwd
Description: Create a new user or update default new user information
Usage: useradd [options] username
Example: useradd newuser
Description: Modify a user account
Usage: usermod [options] username
Example: usermod -aG sudo username
Description: Delete a user account and related files
Usage: userdel [options] username
Example: userdel username
Description: Create a new group
Usage: groupadd [options] groupname
Example: groupadd newgroup
Description: Delete a group
Usage: groupdel [options] groupname
Example: groupdel groupname
Description: Modify a group
Usage: groupmod [options] groupname
Example: groupmod -n newgroupname oldgroupname
Description: Run a command with substitute user and group ID
Usage: su [options] [username]
Example: su -
Description: Define or display aliases
Usage: alias [name='value']
Example: alias ll='ls -l'
Description: Remove alias definitions
Usage: unalias [name]
Example: unalias ll
Description: Command History
Usage: history [options]
Example: history
Description: Clear the terminal screen
Usage: clear
Example: clear
Description: Exit the shell
Usage: exit
Example: exit
Description: Print system information
Usage: uname [options]
Example: uname -a
Description: Print or set the system date and time
Usage: date [options]
Example: date
Description: Display a calendar
Usage: cal [options]
Example: cal
Description: Command-line calculator
Usage: bc [options]
Example: echo "10 + 5" | bc
Description: Print real and effective user and group IDs
Usage: id [options] [username]
Example: id
Description: Show who is logged on and what they are doing
Usage: w [options]
Example: w
Description: Show listing of last logged in users
Usage: last [options]
Example: last
Description: Execute a program periodically, showing output fullscreen
Usage: watch [options] command
Example: watch -n 1 "date"
Description: Schedule commands to be run at a later time
Usage: at [options] time
Example: at now + 1 hour
Description: Schedule periodic background work
Usage: crontab [options]
Example: crontab -e
Description: Shutdown or restart the system
Usage: shutdown [options] [time]
Example: shutdown -r now
Description: Reboot the system
Usage: reboot
Example: reboot
Description: Wrap each input line to fit in specified width
Usage: fold [options] [file]
Example: fold -w 30 myfile.txt
Description: Filter reverse line feeds from input
Usage: col [options]
Example: col -b < input.txt > output.txt
Description: Number lines of files
Usage: nl [options] [file]
Example: nl -s ". " myfile.txt
Description: Reverse lines of a file or files
Usage: rev [options] [file]
Example: rev myfile.txt
Description: Display lines beginning with a given string
Usage: look [options] string [file]
Example: look "apple" /usr/share/dict/words
Description: Print prime factors of specified integer numbers
Usage: factor [options] number
Example: factor 56
Description: Convert units from one scale to another
Usage: units [options]
Example: units "miles/hour" "km/hour"
Description: Refreshes the User Interface Cache, including Home Screen icons
Usage: uicache
Example: uicache
Limited availability: iOS - Jailbroken