Linux Shell Scripting 2

Question 1

Which construct in bash properly iterates over all files in the current directory?

Accepted Answer

for f in *; do echo "$f"; done

Answer

Using glob `*` directly is safer than parsing `ls` output, which breaks on filenames with spaces.

Question 2

What does the special variable `$?` represent in a shell script?

Accepted Answer

The exit status of the last command

Answer

`$?` holds the exit code of the most recently executed foreground command.

Question 3

How do you redirect both stdout and stderr to the same file in bash?

Accepted Answer

cmd > file 2>&1

Answer

`2>&1` redirects stderr (fd 2) to wherever stdout (fd 1) currently points, combining both streams.

Question 4

Which command makes a shell script executable?

Accepted Answer

chmod +x script.sh

Answer

`chmod +x` adds the execute permission bit to the file.

Question 5

What is the purpose of `set -e` at the top of a bash script?

Accepted Answer

Exit the script immediately on any command error

Answer

`set -e` causes the script to exit immediately if any command returns a non-zero exit status.

Linux Practice Test