RHCE Scripting and Task Scheduling

Question 1

Which shebang line is correct for a bash script on RHEL?

Accepted Answer

#!/bin/bash

Answer

`#!/bin/bash` is the correct shebang that tells the kernel to use `/bin/bash` as the interpreter for the script.

Question 2

What does the `$?` variable represent in a bash script?

Accepted Answer

Exit code of the last command

Answer

`$?` holds the exit status of the most recently executed foreground command (0 = success, non-zero = failure).

Question 3

Which `cron` field position represents 'day of the week'?

Accepted Answer

5th field

Answer

In cron syntax, the fields are: minute, hour, day-of-month, month, day-of-week — making day-of-week the 5th field.

Question 4

What command lists all cron jobs for the current user?

Accepted Answer

crontab -l

Answer

`crontab -l` lists (displays) the current user's crontab without editing it.

Question 5

Which special cron string runs a job every day at midnight?

Accepted Answer

All of the above

Answer

`@midnight`, `@daily`, and `0 0 * * *` are all valid cron expressions that schedule a job to run at midnight every day.

RHCE - Red Hat Certified Engineer Practice Test