Package/process ops · Lesson 11 of 20 · 8 minutes

APT DPKG Brew compare

Compare Linux and macOS package inspection tools.

Open the lab Course map

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Your objectives

Hints are always available. Wrong turns never cost XP.

1
List apt packages
Run apt list --installed.
Hint & worked example
Inspect a fixed training package inventory. The simulator cannot install or upgrade your computer.
The command outcome must match the task, including successful access or the explicitly requested failure.
```
apt list --installed
```
Remember: Candidate, installed, and repository versions answer different questions.
2
List dpkg packages
Run dpkg -l.
Hint & worked example
Inspect installed-package records in the synthetic Debian-style environment.
The command outcome must match the task, including successful access or the explicitly requested failure.
```
dpkg -l
```
Remember: Repository availability and installed package state are separate evidence.
3
List brew formulae
Run brew list.
Hint & worked example
Review a synthetic Homebrew package record alongside the Linux-oriented labs.
The command outcome must match the task, including successful access or the explicitly requested failure.
```
brew list
```
Remember: Homebrew and apt are different platform ecosystems; these outputs are training fixtures.

Understand the pattern

Junior operators build confidence by gathering evidence before changing systems.

apt: Inspect a fixed training package inventory. The simulator cannot install or upgrade your computer.
Candidate, installed, and repository versions answer different questions.
dpkg: Inspect installed-package records in the synthetic Debian-style environment.
Repository availability and installed package state are separate evidence.
brew: Review a synthetic Homebrew package record alongside the Linux-oriented labs.
Homebrew and apt are different platform ecosystems; these outputs are training fixtures.

Worked example and expected result

$ apt list --installed

fake-nginx/learn 1.0 installed
fake-openssh/learn 9.9 installed
coreutils/learn 9.5 installed

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

$ dpkg -l

ii  fake-nginx     1.0  training web server
ii  fake-openssh   9.9  training ssh server
ii  coreutils      9.5  training utilities

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

$ brew list

coreutils
nginx
openssh

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 “APT DPKG Brew compare”, which interpretation is safe?A successful first check guarantees that every dependent service is healthy.Repository availability and installed package state are separate evidence.A command appearing in history proves it completed successfully.

Apply it elsewhere

Before adapting the dpkg workflow from “APT DPKG Brew compare” 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: Package file ownership Try an incident drill

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GNU Coreutils manual · GNU Bash manual