LFCS Certification Shell Scripting and Automation 3

Question 1

Which redirection syntax correctly sends both stdout and stderr to a file named output.log?

Accepted Answer

command > output.log 2>&1

Answer

command 2> output.log

Answer

command 1>&2 output.log

Answer

command | tee output.log 2>&1

Question 2

What is the primary purpose of the `trap` command in a bash script?

Accepted Answer

To catch signals or errors and run a specified handler command

Answer

To trap user input and prevent unauthorized keystrokes

Answer

To monitor and limit the execution time of a process

Answer

To capture command output and store it in a named pipe

Question 3

What is a here-document (heredoc) in bash scripting?

Accepted Answer

A block of multi-line text passed as stdin to a command, delimited by a marker word

Answer

A script template that auto-generates inline documentation

Answer

An embedded sub-script defined inside a comment block

Answer

A configuration file that provides environment variables to a script

Question 4

What is the purpose of the `getopts` built-in in a bash script?

Accepted Answer

Parses short command-line options (e.g., -v, -f) passed to the script

Answer

Reads option definitions from the /etc/getopts.conf configuration file

Answer

Returns the count of all available built-in shell options

Answer

Automatically generates a --help usage message for the script

Question 5

Which bash syntax correctly performs integer arithmetic and stores the result in the variable `result`?

Accepted Answer

result=$((num1 + num2))

Answer

result = $num1 + $num2

Answer

result=$(num1 + num2)

Answer

result=`add $num1 $num2`

Question 6

What does the parameter expansion `${#myvar}` return in bash?

Accepted Answer

The length in characters of the string stored in myvar

Answer

The memory address of the variable myvar

Answer

The number of elements in myvar if it is an array

Answer

A hash checksum of the value stored in myvar

Question 7

Which syntax correctly declares a bash array and accesses its second element?

Accepted Answer

arr=(a b c); echo ${arr[1]}

Answer

arr=(a b c); echo $arr[1]

Answer

arr=[a, b, c]; echo $arr[1]

Answer

arr=array(a,b,c); echo ${arr.1}