Over the past two decades, we’ve all gotten used to using GUI apps and desktops, but before that, everything was done in text mode on terminal screens. If you remember the days of MS-DOS or UNIX, then you know the drill. It was all command line, all the time. And somehow, we still managed to get our work done.
The simple fact is that in many ways, sticking with only the command line is often much faster and more efficient. For example, to save a file in the GUI, you need to reach over to the mouse, move the mouse to the File menu, click the Save command, then move your hand back to the keyboard and resume typing. That’s a lot of moving and interaction. Or you could hit Ctrl-S on the keyboard instead. It’s a trade-off. It’s faster using the keyboard, but you have to spend the time to learn it. Repeating this time savings hundreds of times a day really can add up to more time available for other things.
Many text-based apps don’t rely on, or even support, the mouse. Keyboard commands are usually considered “power user tricks” today, but without the mouse, they become a necessity. Productivity skyrockets when you can keep both hands on the keyboard at all times.
Of course, if you are into desktop publishing or video editing, then you really do need graphical tools. Some things just need the GUI. On the other hand, there are many, many tasks that can be done just as well, if not more efficiently, using only the keyboard. If you thought using the Raspberry Pi as your only computer was a fun challenge, try doing it all in text mode!
In this chapter, we’ll look at some of the basic tools that are used to get things done in text mode. This is not a comprehensive tutorial on Linux commands, but we do look at some of the commands, as well as tools you can use along with or sometimes instead of those commands. We’ll first look at Tmux, an app that lets you control multiple “windows” of text at once; then we’ll look at a better terminal app than the one included in Raspbian; and finally, we will look at two file managers that will make your experience moving, copying, backing up, and deleting files much easier. Last, we’ll review some of the basic Linux/Unix file commands that let you manually copy files, move them, delete them, and so forth.
Spicing Up the Command Line
You probably picture the command line as a black screen with a few lines of complex and obscure green text on it. And if that’s what you want, you can certainly do it that way, but there are numerous tools that make staying in the text mode much more like running a windowing GUI. The app Tmux gives you multiple windows. Terminator gives you nice color schemes, font choices, and a different way to split up your screen. Midnight Commander and Ranger make file operations easier and more powerful than trying to memorize a bunch of commands. We’ll look at all these and spice up that boring command line!
Tmux
Tmux Details:
Installation: sudo apt install tmux
Run command: tmux
Dotfile: ~/.tmux.conf
Help: man tmux
Web site: https://github.com/tmux/tmux
Tmux in use
Tmux is what is known as a “terminal multiplexer.” That’s a fancy way of saying it splits your terminal window into smaller panes that each can run a separate program. Figure 5-1 shows a single terminal window running two apps: Vim on the left and a directory listing on the right. This is all done through Tmux.
It doesn’t look like much; probably all you will notice is a colored bar at the bottom of the window. This is typical of command-line apps; they often don’t have fancy menus.
You control Tmux by pressing the Tmux “command key,” which by default is Ctrl-B. To make something happen, you press Ctrl-B and some other key depending on what you want to do. For example, to split the screen vertically, as in Figure 5-1, press Ctrl-B and then press %. Note that to get to %, you also have to hold down the Shift key, so that really works out to be Ctrl-B and then Shift-5 (to get % on a US keyboard).
Various Tmux Commands
Action | Key Combination |
|---|---|
Split window vertically | Ctrl-b % |
Split window horizontally | Ctrl-b ” |
New window | Ctrl-b c |
Close window | Ctrl-d OR Ctrl-b x |
Kill window | Ctrl-b & |
Next window | Ctrl-b n |
Previous window | Ctrl-b p |
Rename window | Ctrl-b , |
List all windows | Ctrl-b w |
Move to window number | Ctrl-b [number] |
Next pane | Ctrl-b o |
Previous pane | Ctrl-b ; |
Show pane numbers | Ctrl-b q |
Move pane left | Ctrl-b { |
Move pane right | Ctrl-b } |
Swap pane locations | Ctrl-b Ctrl-o |
Resize pane down | Ctrl-b Ctrl-j |
Resize pane up | Ctrl-b Ctrl-k |
Resize pane left | Ctrl-b Ctrl-h |
Resize pane right | Ctrl-b Ctrl-l |
That looks like a lot to remember, but you’ll catch on to them quickly enough with use. In the beginning, all you need to remember is Ctrl-B and then either % or ” to split the window either vertically or horizontally; then use Ctrl-B and the arrow keys to navigate between the panes.
In Chapter 7, I will walk you through my “dotfile” configuration file for Tmux, showing you one easy way to change any of these key bindings and otherwise change Tmux’s behavior.
It’s good to get into the habit of opening the terminal app of your choice and then loading Tmux immediately before anything else. That way, if you find yourself needing another app, you can just pop open another window and have it right there. Of course, you can still open two or three or fifteen different terminal windows if you prefer, but again, by staying inside Tmux, you aren’t slowing yourself down with the mouse.
Note
If you are booting into text mode (with no GUI at all), then Tmux is the only way you can have more than one app running at a time.
Terminator
Terminator Details:
Installation: sudo apt install terminator
Run command: tmux
Dotfile: ~/.tmux.conf
Help: man terminator
Web site: https://gnometerminator.blogspot.com/
While the previous app, Tmux, runs in a general terminal window and splits up what you see in different ways, Terminator is an app that replaces the built-in terminal app itself and runs multiple resizable terminal panels in one window.
A trio of Terminator panes
Ranger and Midnight Commander
Ranger Details:
Installation: sudo apt install ranger
Run command: ranger
Dotfile: various files inside ~/.config/ranger/
Help: man ranger
Web site: https://github.com/ranger/rangera
Midnight Commander Details:
Installation: sudo apt install mc
Run command: mc
Dotfile: various files inside /etc/mc/
Help: man mc
Web site: https://midnight-commander.org
Both Midnight Commander and Ranger are file managers. They allow you to easily navigate your computer’s folder hierarchy and copy, move, rename, and delete files, as well as look at previews of the file contents.
It’s completely possible to ignore these two and simply copy files with Unix commands like cp, mv, rm, ls, and so forth; and sometimes it is faster to simply type out your commands. Still, it’s definitely a wise move to learn all the Unix file manipulation commands so you can do things quickly. If you like purely working at a command-line shell, like the one in Figure 5-3, you are always free to do so.
Sometimes, on the other hand, you want to do things with batches of files or more visually browse and navigate your files. Both Midnight Commander and Ranger are good in their own ways, but it’s probably most efficient to pick one or the other and learn to get really good with it.
File listing on the plain command line
File listing with Ranger
File listing with Midnight Commander
Which one you use is entirely up to you. They both do exactly the same things, but their interfaces are completely different. I generally do most file-moving command things right on the command line—see the next section for more on that. If I want to quickly move to a song or load a text file, I’ll zoom quickly to it in Ranger. When I’m doing something with deeply nested paths, or on the occasion where I don’t know where something is or need to dig through a bunch of files and directories, I’ll use Midnight Commander.
Using the Raspberry Pi As a Terminal
So far in this book, we’ve spent lots of time talking about command-line apps and tools that you can run in a terminal window locally on your Pi computer. We’ve even talked about setting your Pi up to run “headless” with no monitor or keyboard. With a headless setup like this, you access the Pi from some other computer using SSH or VNC Viewer.
Those very same tools will work on large remote computers as well, so if you ever come across some application or process that your RPi really, truly, just cannot handle, you may want to look into running that process on someone else’s computer. You can “rent” a remote server from companies such as Linode.com and DigitalOcean.com for two common examples. These systems are inexpensive, at around $5 a month to start, and they are infinitely scalable.
You can sit at your Raspberry Pi, monitor, and mouse and use SSH and VNC Viewer in the terminal app of your choice to work on remote servers. Back in the early chapters, we looked at the built-in Ubuntu Terminal as well as Terminator, but there are literally dozens of other choices here that you can run from the desktop or full-screen command line. You can even access Mac or Windows PCs in this manner, assuming you have them set up with the proper remote access software. If you can’t solve all your problems with a Pi, perhaps you can use it as a window to a larger machine that can do what you need.
Back in the 1970s–1980s, this kind of client-server pairing was very common. People would use “dumb” terminals to connect to “smart” computers and mainframes to get work done. In the age of personal computers, that way of thinking went away for a few decades. Now, in the modern age of “everything is connected to the Internet,” it’s nothing unusual to do work “in the cloud.”
With this style of work, you don’t need much more than a good terminal program like Terminator, which we’ll discuss later, and VNC Viewer, which comes preinstalled with Raspbian. All the computing power you need resides out in the cloud, and your Pi system is more than enough to do literally anything this way.
SSH
SSH Details:
Installation: sudo apt install ssh
Run command: ssh <hostname>
Dotfile: ~/.ssh/config and /etc/ssh/ssh_config
Help: man ssh
Web site: www.openssh.com/
Accessing my Mac via SSH on the Raspberry Pi
VNC Viewer
VNC Viewer Details:
Installation: (see web site)
Menu location: Raspberry Menu ➤ Internet
Help: man vncviewer
Web site: www.realvnc.com/en/connect/download/viewer/raspberrypi/
We discussed setting up the Raspberry Pi as a VNC server back in Chapter 3, and this app does just the opposite; it is the tool you use to log into a computer running the VNC server. It’s like having a complete remote desktop: you can sit in your office and your monitor shows you the desktop of a computer potentially thousands of miles away that you control with your keyboard and mouse.
My Mac via VNC Viewer
Essential Linux Commands
For the most part, 90% of what you’ll enter on the command line are the names of apps. We’ll look at many of them in the next chapter. Emacs, Calcurse, Vim, and even more utility-style apps such as apt and shutdown are really just little programs of their own. Sometimes you need to manipulate a file or a directory, and that’s where this section comes in. Note that all of these commands and much more can be done through an interface such as Midnight Commander, so even when living on the command line, some of these are optional. Still, sometimes it’s just faster or more convenient to simply type in commands rather than work with menus.
Clearing the Screen
at the command line. You’ll see a refreshed, uncluttered terminal screen. It doesn’t do much, but over the years, I’ve probably typed this command more than anything else.
Quitting the Terminal
If you’re running a terminal window, you can simply type exit to end your session and close the window. If you used the option to boot into full-screen mode, then you can’t just exit the terminal; you’ll need to use the reboot or shutdown commands instead.
Listing Files with ls
-l shows the list in the long format, displaying Linux file types, permissions, number of hard links, owner, group, size, last-modified date, and filename.
-a lists all files in the given directory, including those whose names start with “ . ” (which are hidden files in Unix). By default, these files are excluded from the list.
-R recursively lists subdirectories. For example, the command ls -R / would list all files on the system.
-d shows information about a symbolic link or directory, rather than about the link’s target or listing the contents of a directory.
-t sorts the list of files by modification time.
-h prints sizes in human-readable format (e.g., 1K, 234M, 2G, etc.).
So, for one example, we can list all files, including hidden ones, in the current directory, sorted by time, in a detailed format by typing
The Home Directory: ~
The tilde (~) is a special character that represents the current user’s “home” folder. This way you can generically reference “home” no matter who you are or where you are in the system.
This will specifically list the contents of the Music folder for user “brian.”
Moving Around in the File System
Two periods “..” represent the directory located just above the current one. For example, if you are in /home/brian/Music right now, and you want to go to /home/brian, you can simply type cd .. and you’ll move up one level in the structure. Alternately, you could type cd /home/brian, but the two periods are faster to type.
Creating, Deleting, and Listing Directories
Note that you have to have access permission in the current directory in order to make a new directory there.
Removing/deleting a directory requires that the directory be empty. You’ll need to delete any files or subdirectories first.
Sometimes this can be very useful to see where something is hidden or if there is a directory somewhere you’ve forgotten about.
In addition to the cd command, you can also use the command
pwd to have the system tell you where you are right now. Pwd is short for Present Working Directory.
Similarly, if you need to see what the current username is, you can ask
whoami, and the system will tell you your current username. If you log in regularly under your own username and additionally use the superuser “pi” account as well, this can sometimes resolve confusion over who the computer thinks you are.
Removing (Deleting) Files
This command uses a “wildcard” character, the asterisk, to denote “everything.” This command will delete all the files in the user brian’s download directory. This will only delete files, not subdirectories. If you want to delete literally everything in a directory, including everything beneath it, you need the -r and -f options:
rm -rf /home/brian/download/*
The -r tells rm to delete files recursively or, in other words, follow any subdirectories and kill them too. The -f option removes confirmation messages. “Are you sure you want to delete this?” kind of messages will no longer appear.
Note that deleting files recursively can be dangerous. The command rm -rf * will delete everything on the computer—every system file, every data file, for all users, assuming you have permission to access those files; this is one reason Linux relies on the permissions system. It’s much safer than letting every user have complete access to everything.
File Ownership with chown
This will change the file’s ownership to user brian. Note that this requires the “sudo” command to work; this requirement is so not just anyone can change the ownership of files; it has to be someone with responsibility for the system. Remember Linux was created to be a multiple-user operating system with more than one user able to log into the machine, and all this security stuff is designed around that concept.
Copying and Moving Files
will create an exact copy of game.tar in brian’s home directory and then delete the original in the download directory.
will move all files in the /home/username/download directory to the /home/username/backups directory.
Man Pages
If in doubt, read the manual! Seriously, one of the things Linux excels at is thorough documentation on command-line apps. If there’s a command you don’t really understand, you can read a full online manual for it. Let’s say Neofetch confuses you; what exactly does it do? What is the purpose?
Conclusion
To work on the command line, you’re going to need some basic knowledge of Unix/Linux commands. Still, with the right tools, such as Midnight Commander or Ranger, you can minimize the need for memorizing and typing cryptic commands. Another of the terminal’s limitations, that it only shows one app at a time, can be beaten by using Tmux, where you can literally fill your screen with a dozen simultaneously running apps (not that getting too many is a good idea, but you could do it). Lastly, we looked at commands used to manipulate files and directories manually from the command line.
In the next chapter, we’ll look at several dozen command-line programs that will solve many of your work needs. We’ll look at email clients, writing tools, a spreadsheet, and several web browsers, all running in text mode.