010-160 Basic Scripting Concepts 5

Question 1

What does `2>/dev/null` accomplish when appended to a command?

Accepted Answer

Discards standard error output

Answer

`2>` redirects file descriptor 2 (stderr) to `/dev/null`, silently discarding error messages.

Question 2

In bash, what does the `source` command (or `.`) do when given a script path?

Accepted Answer

Executes the script in the current shell environment

Answer

`source` (or `.`) runs the script within the current shell so its variable assignments and functions persist.

Question 3

Which character is used to redirect standard output AND standard error to the same file in bash?

Accepted Answer

2>&1 combined with >

Answer

Using `> file 2>&1` first redirects stdout to the file, then redirects stderr to wherever stdout now points.

Question 4

What is the purpose of double brackets `[[ ]]` compared to single brackets `[ ]` in bash?

Accepted Answer

Double brackets support regex matching and avoid word-splitting issues

Answer

`[[ ]]` is a bash keyword that adds regex matching (`=~`), avoids word-splitting, and handles empty variables more safely.

Question 5

Which special variable contains the process ID of the currently running script?

Accepted Answer

$$

Answer

`$$` expands to the PID of the current shell or script, often used to create unique temporary filenames.

(010-160) LPI Linux Essentials Practice Test