Command Line Navigation Flashcards

Which `ls` option shows hidden files (those starting with a dot)?

Answer: -a

`ls -a` (all) lists all files including those whose names begin with a dot, which are hidden by default.

What is the purpose of the `file` command in Linux?

Answer: Determines the type of a file

The `file` command examines a file's contents and reports its type (e.g., ASCII text, ELF binary, JPEG image).

Which command lists directory contents in long format showing permissions, owner, and size?

Answer: ls -l

`ls -l` displays a detailed long listing including permissions, link count, owner, group, size, and modification time.

What does the `.` (single dot) represent in a Linux filesystem path?

Answer: The current directory

A single dot `.` refers to the current directory, so `./script.sh` runs a script in the current location.

Which command would you use to find out what type of shell you are currently running?

Answer: echo $SHELL

`echo $SHELL` prints the path to the current user's default shell (e.g., /bin/bash).

How would you list all files in /etc that begin with the letter 's' using a wildcard?

Answer: ls /etc/s*

`ls /etc/s*` uses the `*` wildcard to match any filename in /etc that starts with 's'.

What does `ls -lh` display differently than `ls -l`?

Answer: It shows file sizes in human-readable units (KB, MB)

The `-h` (human-readable) flag formats file sizes with units like K, M, G instead of raw byte counts.