LFCS Certification Shell Scripting and Automation

Question 1

What is the purpose of the shebang line (e.g., #!/bin/bash) at the top of a shell script?

Accepted Answer

It specifies the interpreter to use when executing the script

Answer

The shebang line tells the operating system which interpreter to use to execute the script when it is run directly.

Question 2

Which command makes a shell script executable for the file owner, group, and others?

Accepted Answer

chmod +x script.sh

Answer

chmod +x adds the execute permission bit for owner, group, and others, making the script runnable.

Question 3

What is the correct bash syntax to check if the integer variable $NUM equals 10?

Accepted Answer

if [ $NUM -eq 10 ]

Answer

The -eq operator is the correct arithmetic comparison operator for integers inside single bracket [ ] test expressions in bash.

Question 4

Which special variable holds the exit status of the most recently executed command?

Accepted Answer

$?

Answer

$? stores the exit code of the last foreground command; 0 means success and any non-zero value indicates failure.

Question 5

What is the correct way to assign the string 'admin' to the variable USERNAME in bash?

Accepted Answer

USERNAME='admin'

Answer

In bash, variable assignment uses no spaces around the = sign; spaces would cause bash to interpret it as a command.

LFCS Certification Practice Test