March 11, 2025

HPR4332: Top 5 mistakes every new terminal user makes

25 minutes

This show has been flagged as Clean by the host.

Learning to use the terminal is an important step in becoming a

true power user of Linux, but it’s easy (and normal) to make

mistakes along the way. Here are the top 5 mistakes new terminal

users make, and what you can learn from them.

1. Current working directory

When you first open a terminal, your current working directory

is your home folder. You have access to all those directories

you see in your home directory every time you open a file

manager (Desktop, Documents, Downloads,

Music, Pictures, and Videos).

You can verify your location with the pwd command:

$ pwd

/home/seth

You can list the files and folders within your current

directory with the ls or dir or tree

commands:

$ ls

Desktop Documents Downloads

Music Pictures Videos

But you don’t usually stay in one place while using the

terminal. You frequently move from folder to folder so you can

open or modify or edit files. It’s easy to get lost, forgetting

what directory you’re in and what files are around you.

Lesson learned: When working in the terminal,

it’s important to regularly verify your current working

directory with pwd so you don’t accidentally issue

a command you intended to run in a different location.

2. Use interactive options when using

wildcards

Wildcards are great shorthand to make command entry faster, and

to perform bulk actions on lots of files. However, they can be

dangerous when you get them wrong.

It’s easy to process hundreds of the wrong files by using a

wildcard in the wrong directory, or by using a wildcard that’s

too broad.

For example, suppose you want to run a sed

command on all HTML files in a directory, so you run this:

$ sed --in-place 's/day/night/g' *ml

Job done, until you find out that you accidentally ran that

command on all your XML files, too.

Lesson learned: Run a safe test command on the

wildcard you think you want to target before making a

change. Some commands have a literal --dry-run

option. Others have an --interactive option that

forces the command to prompt you to confirm that you want to

carry out the action. Sometimes the logic is reversed: a command

refuses to make a major change unless you use a command (for

example, sed doesn’t write changes to a file

without the --in-place option or redirection).

When in doubt, improvise. You can always “expand” a wildcard

using the echo command:

$ echo ./*ml

./four.html ./one.xml ./three.html ./two.xml

$ echo ./*tml

./four.html ./three.html

3. File paths

Many new terminal users don’t understand where files are

located within the file system. It’s not a common mistake to

make on the desktop because there are visual reminders there.

You wouldn’t try to double-click on a document to open it if

there was no icon to double-click. It’s easy to assume that the

terminal application contains all your files all at once, but

the terminal is, by design, limited in scope. Were the terminal

to have access to every file everywhere on your system all at

once, you’d end up accidentally renaming and moving and copying

a lot more files than intended. Specificity is a super power,

and it’s defined by the file path.

A file path describes where a file exists in a file system. A

full (or “absolute”) file path always starts from the single

folder at the start of your operating system, indicated by just

a /, and then lists each folder within that folder

until it traces the path to a specific file. For example, I have

a file called IMG_0001.JPG in my Pictures

directory. You probably have a mental image of where that file

is and how you’d get there on the desktop. But for the terminal

to understand how to find it, the location must be expressed as

/home/seth/Pictures/IMG_0001.JPG.

An absolute file path is definitive. The terminal always

understands an absolute file path, no matter what your current

working directory is.

The absolute path to a file can be unwieldy, though. Once you

understand absolute paths, you can abbreviate any path to a relative

file path.

A relative file path is based on your current location in the

terminal. As long as you’re in the Pictures

folder, the full path /home/seth/Pictures/IMG_0001.JPG

can be shortened to just IMG_0001.JPG, or ./IMG_0001.JPG

for added clarity (the . indicates no movement

from your current location, and the / is a

directory separator as usual).

But suppose your current working directory was your home

directory. Your Pictures folder is located in your

home directory, so to get to IMG_0001.JPG you have

to enter Pictures first. The relative path in that

case is ./Pictures/IMG_0001.JPG or just Pictures/IMG_0001.JPG.

Lesson learned: An absolute file path always

starts from the start of a file system. A relative file path

changes based on your location. The terminal understands both.

For new users, the absolute file path is the most explicit and

exact way to reference a file, so practice using them until

you’re comfortable with the concept of file paths.

4. Executable permissions

By default, most files aren’t executable. You can’t run them

like an application, because most files are meant to be opened in

an application. That’s not true for shell scripts, though.

Shell scripts are text files containing a list of commands, and

they’re meant to be run like an application. They’re a powerful

way to string existing commands together to form a new custom

command. However, because a shell script starts out as a regular

text file, it’s not seen by your terminal as an executable

entity.

To execute a file as an application, you can grant it

executable permission with the chmod command:

$ chmod +x ./example.sh

Alternatively, you can run the file in a sub-shell:

$ bash ./example.sh

Notice that in these examples, I use the ./

notation as if the example.sh shell script exists

in my current directory.

5. Typing errors

It sometimes feels like the more you type, the more you’re

getting done. In a terminal, though, typing too much is one of

the best ways to introduce mistakes.

When you try to type a long and complex command, you’re liable

to spell something wrong or use the wrong option. When you try

to type a filename or a file path, you might forget to escape

special characters (like spaces). The errors aren’t usually

catastrophic, but they’re frustrating and time consuming.

Lesson learned: There are several ways to

ensure you’re entering the correct commands into your terminal:

Copy and paste: If you’re using a command

you found on a trusted website, copy it in your browser and

then paste it into your terminal using Ctrl+Shift+V

or right-click and select Paste.

TAB: You can type part of a command or file

path, and then press the TAB key on your

keyboard for either auto-completion or for suggested

completions. Use it even when you don’t think you need it.

It’ll save you errors every single time, even when

it appears to not work (hint: it’s not working because you’re

trying to auto-complete something that’s not where you think

it is).

Drag-and-drop: It’s the 21st century! You

can drag a file or folder from anywhere on your computer, and

drop it into your terminal. It gets replaced by its absolute

path automatically.

Practice makes perfect

To get good in the terminal, you have to use it as often as you

can. You don’t have to use it for “serious” work at first, and

you arguably shouldn’t, but you can and should do simple

exercises in the terminal. Understand file paths, get used to

wildcards, learn shortcuts, use the TAB key.

The biggest mistake you can make when learning the terminal is

to not use the terminal, so open it up every day, do your

exercise, and you’ll be an expert in the terminal in no time.

Provide feedback on this episode.

...more

View all episodes

By Hacker Public Radio

4.2

3434 ratings