Common Linux commands
| Command | Description |
| cat [filename] | Display the file’s contents to the standard output device (usually your monitor). |
| cd /directorypath | Change to directory. |
| chmod [options] mode filename | Change a file’s permissions. |
| chown [options] filename | Change who owns a file. |
| clear | Clear a command-line screen/window for a fresh start. |
| cp [options] source destination | Copy files and directories. |
| date [options] | Display or set the system date and time. |
| df [options] | Display used and available disk space. |
| du [options] | Show how much space each file takes up. |
| file [options] filename | Determine what type of data is within a file. |
| find [pathname] [expression] | Search for files matching a provided pattern. |
| grep [options] pattern [filename] | Search files or output for a particular pattern. |
| kill [options] pid | Stop a process. If the process refuses to stop, use kill -9 pid. |
| less [options] [filename] | View the contents of a file one page at a time. |
| ln [options] source [destination] | Create a shortcut. |
| locate filename | Search for the specified filename. |
| lpr [options] | Send a print job. |
| ls [options] | List directory contents. |
| man [command] | Display the help information for the specified command. |
| mkdir [options] directory | Create a new directory. |
| mv [options] source destination | Rename or move file(s) or directories. |
| passwd [name [password]] | Change the password or allow (for the system administrator) to change any password. |
| ps [options] | Display a snapshot of the currently running processes. |
| pwd | Display the pathname for the current directory. |
| rm [options] directory | Remove (delete) file(s) and/or directories. |
| rmdir [options] directory | Delete empty directories. |
| ssh [options] user@machine | Remotely log in to another Linux machine, over the network. Leave an ssh session by typing exit. |
| su [options] [user [arguments]] | Switch to another user account. |
| tail [options] [filename] | Display the last n lines of a file (the default is 10). |
| tar [options] filename | Store and extract files from a tarball (.tar) or a compressed tarball (.tar.gz or .tgz). |
| top | Displays the resources being used on your system. Press Q to exit. |
| touch filename | Create an empty file with the specified name. |
| who [options] | Display who is logged on. |
To access your CDs/DVDs and USB sticks:
- If you’re in the graphical user interface (GUI), the media should be automatically detected.
- On the command line, look in the /media directory. You may need to use mount /media/cdrom, /media/dvdrom, or some other variant.
To remove your CDs/DVDs and USB sticks:
- In the GNOME 3 desktop, right-click the media’s icon and select Eject from the context menu. If you’re using the KDE Plasma desktop, select the Device Notifier icon in the Panel, and then select the CD or USB icon to eject.
- On the command line, type umount /media/cdrom, where you should change cdrom to whatever you had to use to mount the item.
Accessing Linux help pages
To find help, try the following commands:
- man -k [keyword]: Search a database for commands that involve the keyword. Can also be used as apropos [keyword].
- info [command]: Display a file’s help information in an alternate format.
- man [command]: Display a file’s help information.
- whatis [command]: Display a short blurb about the command.
You can also check the following documentation:
- openSUSE: The openSUSE documentation (https://doc.opensuse.org) provides a complete reference guide to both the openSUSE environment and the GNOME 3 desktop environment. There’s also a user forum (https://forums.opensuse.org) where users can post and answer specific questions about using openSUSE.
- Rocky Linux: The Rocky Linux documentation web page (https://docs.rockylinux.org) provides access to guides (short how-to documentation), books (longer-format documentation), labs (step-by-step work-throughs of processes), and gemstones (very short how-to documents).
- Ubuntu: The official Ubuntu documentation (https://help.ubuntu.com) provides basic information on how to get started with most common desktop tasks. Just look for the topic area you’re interested in and follow the thread. Ubuntu also has a wiki (https://wiki.ubuntu.com), where Ubuntu users can contribute their own guides and tutorials.