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Filesystem navigation is security-relevant because path context changes what a command touches. `pwd` tells you where you are, `cd` changes that location, and `ls` gives you a view of the current directory. In an audit shell, prefer explicit paths when the consequence of operating on the wrong directory is high. A prompt is not evidence of location.
Relative paths are resolved against the process working directory. `.` means the current directory, `..` its parent, and `~` is expanded by the shell to the current user’s home directory. The kernel ultimately receives pathnames, but Bash may perform expansion before an external program starts. That is why quoting and path tests belong in your mental model even during basic navigation.
Shows the shell process working directory. The useful habit here is to treat the command output as evidence about one system fact, not as a magical diagnosis.
Tool choice is situational. Start with the narrowest command that answers the question, then escalate to a heavier tool only when the first observation leaves a real gap.
Scripts often fail because their author assumes the current directory is the script directory. Launching `./audit.sh` from one directory and `bash /opt/tools/audit.sh` from another can produce different results if the script uses relative paths. For security automation, derive paths deliberately rather than relying on the caller’s working directory.
Changes the shell working directory to a common location for security telemetry. Read the result in context: the same command can be correct yet insufficient if a permission boundary, alternate configuration, or different backend changes what it reports.
Reads Bash’s current working-directory variable after navigation; useful when logging context. In a production workflow, save the raw result when the observation contributes to a finding. That keeps later analysis honest and makes troubleshooting reproducible.
A practitioner’s checkpoint: compare the observed behavior with the assumption your script is about to make. If the assumption is broader than the evidence, narrow the rule. If the evidence is incomplete, report the uncertainty instead of converting it into a confident finding.
Lab discipline: stay inside the declared course environment, prefer read-only checks for learning exercises, and preserve the original output of security tools before transforming it.
Finish the lesson once you have worked through the material. This awards ★ 35 XP.