Terminal basics · Lesson 29 of 34 · 8 minutes

Builtins and executable paths

Compare shell builtins with commands found on PATH.

Open the lab Course map

Mastery 0/3Run itExplain itApply it

learner@clairos:~ $

↑ history · Tab complete · Ctrl+C cancel · Esc, Tab to leaveExit 0

Your objectives

Hints are always available. Wrong turns never cost XP.

1
Identify a builtin
Run type cd.
Hint & worked example
Describe the shell command resolution for a supported name.
The command outcome must match the task, including successful access or the explicitly requested failure.
```
type cd
```
Remember: Shell builtins and external commands are not resolved in exactly the same way.
2
Identify an executable
Run type ls.
Hint & worked example
Describe the shell command resolution for a supported name.
The command outcome must match the task, including successful access or the explicitly requested failure.
```
type ls
```
Remember: Shell builtins and external commands are not resolved in exactly the same way.
3
Print the executable path
Run which ls.
Hint & worked example
Find the simulated executable path for a command.
The command outcome must match the task, including successful access or the explicitly requested failure.
```
which ls
```
Remember: A path lookup does not prove that running the command will succeed.

Understand the pattern

Distinguishing shell builtins from executable commands helps operators explain what they know before they change anything.

type: Describe the shell command resolution for a supported name.
Shell builtins and external commands are not resolved in exactly the same way.
which: Find the simulated executable path for a command.
A path lookup does not prove that running the command will succeed.

Worked example and expected result

$ type cd

cd is a shell builtin in the simulated terminal

Exit status: 0. The command completed successfully in the training fixture.

$ type ls

ls is /bin/ls

Exit status: 0. The command completed successfully in the training fixture.

$ which ls

/bin/ls

Exit status: 0. The command completed successfully in the training fixture.

Try a variation

Repeat this workflow in the sandbox with a different scratch filename. Keep the system fixtures unchanged and compare the observed output with your expectation before moving on.

Explain it

In “Builtins and executable paths”, which interpretation is safe?A successful first check guarantees that every dependent service is healthy.Shell builtins and external commands are not resolved in exactly the same way.A command appearing in history proves it completed successfully.

Apply it elsewhere

Before adapting the type workflow from “Builtins and executable paths” to another server, what should you do?Confirm the current directory, target identity, permissions, and the installed command behavior first.Paste the training paths unchanged into production.Skip output inspection whenever the command is familiar.

Keep the momentum.

Complete the lab, then explain and apply the pattern.

Next: Output capture contract Try an incident drill

Anonymous lesson and mastery progress lasts for this session. Sign in to keep synced lesson XP between sessions; mastery stays device-local. No speed bonus, lost lives, or hint penalties.

Keep learning

GNU Coreutils manual · GNU Bash manual