Basic Unix Commands
Knowing basic Unix commands should allow you to navigate your Unix or Linux system, confirm current system status and manage files or directories.
UPDATE 09/2024: I’ll be publishing a short video walkthrough of Basic Unix Commands here at the top of the page shortly.
Getting help in Unix
- man – view manual pages for Unix commands
Unix Shell Commands
- clear – clear screen
- history – show history of previous commands
Time and Date commands
- date – show current date and time
- sleep – wait for a given number of seconds
- uptime – find out how long the system has been up
Unix users commands
These commands allow you to get basic information about Unix users in your environment.
- whoami – show your username
- id – print user identity
- groups – show which groups user belongs to
- passwd – change user password
- who – find out who is logged into the system
- last – show history of logins into the system
Unix file operations
Navigating filesystem and managing files and access permissions:
- ls – list files and directories
- cp – copy files (work in progress)
- rm – remove files and directories (work in progress)
- mv – move or rename files and directories to another location
- chmod – change file/directory access permissions
- chown – change file/directory ownership
Text file operations in Unix
Most of important configuration in Unix is in clear text files, these commands will let you quickly inspect files or view logs:
- cat – concatenate files and show contents to the standard output
- more – basic pagination when viewing text files or parsing Unix commands output
- less – an improved pagination tool for viewing text files (better than more command)
- head – show the first 10 lines of text file (you can specify any number of lines)
- tail – show the last 10 lines of text file (any number can be specified)
- grep – search for patterns in text files
Unix directory management commands
Navigating filesystems and managing directories:
- cd – change directory
- pwd – confirm current directory
- ln – make links and symlinks to files and directories
- mkdir – make new directory
- rmdir – remove directories in Unix
Unix system status commands
Most useful commands for reviewing hostname configuration and vital stats:
- hostname – show or set server hostname
- w – display system load, who’s logged in and what they are doing
- uname – print Unix system information
Reboot
- shutdown – graceful shutdown and reboot of your system
- halt – ungraceful (without stopping OS services) shutdown
- reboot – ungraceful reboot (without stopping OS services)
Networking commands in Unix
Most useful commands for inspecting network setup and exploring network connections and ports:
- ifconfig – show and set IP addresses (found almost everywhere)
- ip – show and set IP addresses (in recent Linux versions)
- ping – check if remote host is reachable via ICMP ping
- netstat – show network stats and routing information
Process management
Listing processes and confirming their status, and stopping processes if needed:
- ps – list processes
- top – show tasks and system status (check out htop as well)
- kill – kill a process (stop application running)
Remote access commands
ssh is really the only way to go, but it’s important to know telnet as well:
- telnet – clear-text (insecure) remote access protocol
- ssh – Secure SHell – encrypted remote access client
- check out the SSH reference!
File transfers commands
Always useful to know how to copy files between servers or just download some package from the web:
- ftp – clear-text (insecure!) File Transfer Protocol client
- sftp – secure (encrypted) version of FTP
- scp – secure (encrypted) version of cp command
- wget – download files from remote servers, HTTP/HTTPS and FTP
- curl – download files from remote servers, HTTP/HTTPS and FTP
See Also
Knowing basic Unix commands should allow you to navigate your Unix or Linux system, confirm current system status and manage files or directories.
UPDATE 09/2024: I’ll be publishing a short video walkthrough of Basic Unix Commands here at the top of the page shortly.
Getting help in Unix
- man – view manual pages for Unix commands
Unix Shell Commands
- clear – clear screen
- history – show history of previous commands
Time and Date commands
- date – show current date and time
- sleep – wait for a given number of seconds
- uptime – find out how long the system has been up
Unix users commands
These commands allow you to get basic information about Unix users in your environment.
- whoami – show your username
- id – print user identity
- groups – show which groups user belongs to
- passwd – change user password
- who – find out who is logged into the system
- last – show history of logins into the system
Unix file operations
Navigating filesystem and managing files and access permissions:
- ls – list files and directories
- cp – copy files (work in progress)
- rm – remove files and directories (work in progress)
- mv – move or rename files and directories to another location
- chmod – change file/directory access permissions
- chown – change file/directory ownership
Text file operations in Unix
Most of important configuration in Unix is in clear text files, these commands will let you quickly inspect files or view logs:
- cat – concatenate files and show contents to the standard output
- more – basic pagination when viewing text files or parsing Unix commands output
- less – an improved pagination tool for viewing text files (better than more command)
- head – show the first 10 lines of text file (you can specify any number of lines)
- tail – show the last 10 lines of text file (any number can be specified)
- grep – search for patterns in text files
Unix directory management commands
Navigating filesystems and managing directories:
- cd – change directory
- pwd – confirm current directory
- ln – make links and symlinks to files and directories
- mkdir – make new directory
- rmdir – remove directories in Unix
Unix system status commands
Most useful commands for reviewing hostname configuration and vital stats:
- hostname – show or set server hostname
- w – display system load, who’s logged in and what they are doing
- uname – print Unix system information
Reboot
- shutdown – graceful shutdown and reboot of your system
- halt – ungraceful (without stopping OS services) shutdown
- reboot – ungraceful reboot (without stopping OS services)
Networking commands in Unix
Most useful commands for inspecting network setup and exploring network connections and ports:
- ifconfig – show and set IP addresses (found almost everywhere)
- ip – show and set IP addresses (in recent Linux versions)
- ping – check if remote host is reachable via ICMP ping
- netstat – show network stats and routing information
Process management
Listing processes and confirming their status, and stopping processes if needed:
- ps – list processes
- top – show tasks and system status (check out htop as well)
- kill – kill a process (stop application running)
Remote access commands
ssh is really the only way to go, but it’s important to know telnet as well:
- telnet – clear-text (insecure) remote access protocol
- ssh – Secure SHell – encrypted remote access client
- check out the SSH reference!
File transfers commands
Always useful to know how to copy files between servers or just download some package from the web:
- ftp – clear-text (insecure!) File Transfer Protocol client
- sftp – secure (encrypted) version of FTP
- scp – secure (encrypted) version of cp command
- wget – download files from remote servers, HTTP/HTTPS and FTP
- curl – download files from remote servers, HTTP/HTTPS and FTP
