devsetup1-2  Exercise 2: What Is Already Installed?
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STEP 1: RECORD THE STARTING STATE
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For each tool, ask dpkg whether the package is installed. This prints the
status line for installed packages and an error for missing ones:

    for p in build-essential curl wget git vim htop tree unzip zip jq ripgrep \
             ca-certificates gnupg pciutils; do
      if dpkg -s "$p" >/dev/null 2>&1; then echo "installed:   $p"; else echo "NOT installed: $p"; fi
    done | tee ~/before.txt

STEP 2: INSTALL THE WHOLE LIST
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    sudo apt install build-essential curl wget git vim htop tree unzip zip jq ripgrep \
      ca-certificates gnupg pciutils

Read apt's summary before answering y. It has three lists that answer the
question directly:
  - "The following NEW packages will be installed:" is what actually needed
    installing.
  - Packages that were already present do not appear in that list. apt also
    prints lines such as "git is already the newest version" for tools that
    were already there.
  - "0 upgraded, N newly installed" gives the count.

Compare the NEW list with ~/before.txt. Every name marked NOT installed there
should appear in the NEW list; every name marked installed should not.

STEP 3: PRINT THE VERSIONS
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    gcc --version | head -n 1
    make --version | head -n 1
    curl --version | head -n 1
    wget --version | head -n 1
    git --version
    vim --version | head -n 1
    htop --version
    tree --version
    unzip -v | head -n 1
    zip -v | head -n 2 | tail -n 1
    jq --version
    rg --version | head -n 1
    gpg --version | head -n 1
    lspci --version

Note that a few packages (build-essential, ca-certificates) are not commands.
build-essential installs gcc and make, and ca-certificates installs data
files. Checking the tools they provide is how you verify them.

WHY THIS WORKS AS AN ANSWER
---------------------------
Recording the starting state first turns "I think it was already there" into
evidence. It also previews Chapter 3, where checking before installing
becomes a routine habit rather than an exercise.