The Linux operating system offers a powerful array of commands to manage files, navigate directories, control processes, and interact with the system. This diverse toolkit empowers users to manipulate their environment efficiently. Commands like ls, cd, and pwd facilitate directory navigation, while cp and mv allow for copying and moving files. To manage processes, ps, top, and kill provide insight and control. System information is available through commands like uname and free. The system’s network capabilities are harnessed by commands such as ping, ssh, and netstat. Additionally, administrative tasks are supported by commands like useradd, chown, and shutdown. Overall, these commands exemplify Linux’s flexibility and functionality.
| Command | Syntax | Description | Example | 
|---|---|---|---|
| ls | ls [options] [directory] | List files and directories | ls -l /home/user/documents | 
| cd | cd [directory] | Change the current directory | cd /var/www/html | 
| pwd | pwd | Print the current working directory | pwd | 
| cp | cp [options] source destination | Copy files or directories | cp file.txt /backup/ | 
| mv | mv [options] source destination | Move or rename files or directories | mv oldfile.txt newfile.txt | 
| rm | rm [options] file/directory | Remove files or directories | rm -rf folder/ | 
| mkdir | mkdir [options] directory | Create a new directory | mkdir new_folder | 
| rmdir | rmdir directory | Remove an empty directory | rmdir empty_folder | 
| touch | touch filename | Create an empty file | touch newfile.txt | 
| cat | cat filename | Display the contents of a file | cat myfile.txt | 
| echo | echo [options] message | Print a message or value to terminal | echo “Hello, world!” | 
| grep | grep [options] pattern file | Search for patterns in files | grep “error” logfile.txt | 
| chmod | chmod [options] permissions file | Change file permissions | chmod 755 script.sh | 
| chown | chown [options] user:group file | Change file ownership | chown user:group myfile.txt | 
| ps | ps [options] | Display information about processes | ps aux | 
| top | top | Display dynamic list of processes | top | 
| kill | kill [options] process_id | Terminate a process | kill 1234 | 
| df | df [options] | Display disk space usage | df -h | 
| du | du [options] directory/file | Display file/directory space usage | du -sh /path | 
| free | free [options] | Display memory usage | free -h | 
| uname | uname [options] | Print system information | uname -a | 
| date | date [options] | Display or set system date and time | date | 
| cal | cal [options] | Display calendar | cal | 
| who | who [options] | Display logged-in users | who | 
| w | w | Display information about users | w | 
| id | id [options] username | Display user and group information | id john | 
| history | history [options] | Display command history | history | 
| clear | clear | Clear the terminal screen | clear | 
| man | man command | Display manual page for command | man ls | 
| info | info command | Display info page for command | info ls | 
| alias | alias [options] | Create or display command aliases | alias ll=’ls -l’ | 
| file | file filename | Determine file type | file myfile.txt | 
| tar | tar [options] | Archive and extract files | tar -cvf archive.tar files | 
| zip | zip [options] archive files | Create compressed archive | zip archive.zip file1.txt file2.txt | 
| unzip | unzip [options] archive | Extract files from compressed archive | unzip archive.zip | 
| ssh | ssh [options] user@host | Connect to remote host using SSH | ssh [email protected] | 
| scp | scp [options] source destination | Copy files securely over SSH | scp file.txt [email protected]:/path/ | 
| rsync | rsync [options] source destination | Sync files and directories | rsync -avz source/ destination/ | 
| wget | wget [options] URL | Download files from the web | wget https://example.com/file.txt | 
| curl | curl [options] URL | Transfer data to/from URLs | curl -O https://example.com/file.txt | 
| ping | ping [options] host | Test network connectivity | ping google.com | 
| ifconfig | ifconfig [options] | Configure network interfaces | ifconfig | 
| ip | ip [options] | Manage network interfaces | ip addr show | 
| route | route [options] | Display or manipulate routing table | route -n | 
| netstat | netstat [options] | Network statistics | netstat -tuln | 
| nslookup | nslookup domain | DNS lookup | nslookup google.com | 
| dig | dig domain | DNS lookup (more advanced) | dig google.com | 
| traceroute | traceroute host | Display route and delay to host | traceroute google.com | 
| whois | whois domain | Get domain registration info | whois example.com | 
| uptime | uptime | Display system uptime | uptime | 
| shutdown | shutdown [options] | Shutdown or restart system | shutdown -h now | 
| reboot | reboot | Reboot the system | reboot | 
| ifup | ifup interface | Bring a network interface up | ifup eth0 | 
| ifdown | ifdown interface | Take a network interface down | ifdown eth0 | 
| systemctl | systemctl [options] command service | Manage systemd services | systemctl start apache2 | 
| service | service [options] command service | Control system services | service apache2 start | 
| useradd | useradd [options] username | Create a new user | useradd john | 
| userdel | userdel [options] username | Delete a user | userdel john | 
| passwd | passwd [options] username | Change user password | passwd john | 
| groupadd | groupadd [options] groupname | Create a new group | groupadd developers | 
| groupdel | groupdel [options] groupname | Delete a group | groupdel developers | 
| su | su [options] username | Switch user | su john | 
| sudo | sudo command | Execute command with superuser privileges | sudo apt update | 
| adduser | adduser username | Add a user interactively | adduser sarah | 
| deluser | deluser username | Delete a user and associated files | deluser sarah | 
| passwd | passwd username | Change user password | passwd sarah | 
| addgroup | addgroup groupname | Add a group | addgroup team1 | 
| delgroup | delgroup groupname | Delete a group | delgroup team1 | 
| chmod | chmod [options] permissions file | Change file permissions | chmod 644 myfile.txt | 
| chown | chown [options] user:group file | Change file ownership | chown user:group myfile.txt | 
| find | find [options] path expression | Search for files and directories | find /var/log -name “*.log” | 
| locate | locate keyword | Search for files using an index | locate myfile.txt | 
| ln | ln [options] source link | Create symbolic or hard links | ln -s target link | 
| mount | mount [options] device mountpoint | Mount a filesystem | mount /dev/sdb1 /mnt | 
| umount | umount [options] mountpoint | Unmount a filesystem | umount /mnt | 
| df | df [options] | Display disk space usage | df -h | 
| du | du [options] directory/file | Display file/directory space usage | du -sh /path | 
| free | free [options] | Display memory usage | free -h | 
| uname | uname [options] | Print system information | uname -a | 
| date | date [options] | Display or set system date and time | date | 
| cal | cal [options] | Display calendar | cal | 
| who | who [options] | Display logged-in users | who | 
| w | w | Display information about users | w | 
| id | id [options] username | Display user and group information | id john | 
| history | history [options] | Display command history | history | 
| clear | clear | Clear the terminal screen | clear | 
| man | man command | Display manual page for command | man ls | 
| info | info command | Display info page for command | info ls | 
