devsetup1-3  Exercise 2: A check-tools.sh Script
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THE SCRIPT (save as check-tools.sh)
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    #!/usr/bin/env bash
    # check-tools.sh CMD...
    # Report presence, path and first line of version output for each command.
    # Exit status is non-zero if any command is missing.

    missing=0
    for cmd in "$@"; do
      if path=$(command -v "$cmd"); then
        ver=$("$cmd" --version 2>&1 | head -n 1)
        printf '%-10s FOUND    %-22s %s\n' "$cmd" "$path" "$ver"
      else
        printf '%-10s MISSING\n' "$cmd"
        missing=1
      fi
    done
    exit "$missing"

RUNNING IT
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    chmod +x check-tools.sh
    ./check-tools.sh git curl wget vim htop tree jq rg gpg lspci gcc make
    echo "exit status: $?"

Expected: one FOUND line per tool and "exit status: 0" if the Chapter 2
starter tools are all installed. To see the failure path:

    ./check-tools.sh git nonexistent-tool
    echo "exit status: $?"

which prints MISSING for nonexistent-tool and "exit status: 1".

HOW IT WORKS
------------
- "if path=$(command -v "$cmd")" both tests for existence and captures the
  path in one step. command -v exits non-zero when the command is not found,
  so the if takes the else branch.
- The version line uses --version and head -n 1 to keep output to one line.
- 2>&1 is included because some tools print version text to standard error.
- missing is set to 1 on any failure and used as the final exit status, so
  the script can be used in other scripts: ./check-tools.sh git || exit 1

KNOWN LIMITATIONS
-----------------
- Not every tool understands --version. unzip and zip, for example, use -v,
  and may print usage text instead. The script will still report them as
  FOUND, because it tests existence first.
- It checks commands, not packages. To check a package by name, use the
  pkg_installed function from the chapter.

WHY THIS WORKS AS AN ANSWER
---------------------------
It turns the check into something repeatable: the same one command can be run
on devserver now and on a rebuilt machine later. Returning a proper exit
status is what lets Chapter 10's provisioning script reuse it.