LFCS Certification Shell Scripting and Automation 2

Question 1

What does the command substitution syntax $(command) do in a bash script?

Accepted Answer

Captures the stdout output of a command and inserts it inline

Answer

Command substitution executes the command inside $() and replaces the expression with the command's standard output.

Question 2

In a bash script, how do you correctly access the third positional argument passed to the script?

Accepted Answer

$3

Answer

$3 refers to the third positional parameter; $0 is the script name, $1 is the first argument, and so on.

Question 3

What does the `shift` command do when called in a bash script?

Accepted Answer

Shifts all positional parameters left by one, dropping $1

Answer

shift discards $1 and renumbers the remaining positional parameters so that $2 becomes $1, $3 becomes $2, and so on.

Question 4

Which test expression correctly checks that a path exists and is a regular file (not a directory)?

Accepted Answer

[ -f filename ]

Answer

-f returns true only if the path exists and is a regular file, while -e returns true for any existing path regardless of type.

Question 5

What is the key distinction between the `=` operator and `-eq` in bash conditional tests?

Accepted Answer

`=` compares strings lexicographically and `-eq` compares integers numerically

Answer

Using = for integer comparison may work by coincidence but performs string comparison, while -eq correctly evaluates numeric equality.

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