wait for background processes in Bash Scripting - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to wait for all background processes to finish before continuing.

Bash Scripting

echo "Start"; sleep 2 & sleep 3 & [1]; echo "Done"

Drag options to blanks, or click blank then click option'

Aexit

Bsleep

Cwait

Dkill

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'sleep' instead of 'wait' does not wait for background jobs.

Using 'kill' or 'exit' will stop the script or processes incorrectly.

The 'wait' command pauses the script until all background jobs finish.

2fill in blank

medium

Complete the code to wait for a specific background process using its process ID.

Bash Scripting

sleep 5 & pid=$!; echo "Waiting for process"; [1] $pid; echo "Process done"

Drag options to blanks, or click blank then click option'

Await

Bsleep

Ckill

Djobs

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'kill' will terminate the process instead of waiting.

Using 'jobs' only lists jobs but does not wait.

The 'wait' command can take a process ID to wait for that specific job.

3fill in blank

hard

Fix the error in the code to properly wait for all background jobs before printing "Finished".

Bash Scripting

sleep 4 & sleep 3 & sleep 2 & [1]; echo "Finished"

Drag options to blanks, or click blank then click option'

Await $!

Bwait

Csleep

Dkill

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'wait $!' waits only for the last job, not all jobs.

Using 'sleep' or 'kill' does not wait properly.

Using 'wait' without arguments waits for all background jobs, ensuring 'Finished' prints last.

4fill in blank

hard

Fill both blanks to create a loop that waits for each background job individually using their PIDs stored in an array.

Bash Scripting

pids=(); sleep 3 & pids+=($!); sleep 2 & pids+=($!); for pid in "${pids[@]}"; do [1] $pid; done; echo [2]

Drag options to blanks, or click blank then click option'

Await

Bsleep

C"All jobs done"

D"Done"

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'sleep' inside the loop does not wait for jobs.

Printing the wrong message or before waiting.

The loop uses 'wait' on each PID to wait for each job, then prints a message after all finish.

5fill in blank

hard

Fill all three blanks to start three background jobs, wait for all, and then print a summary message.

Bash Scripting

sleep 1 & sleep 2 & sleep 3 & [1]; echo [2] [3]

Drag options to blanks, or click blank then click option'

Await

B"All"

C"background jobs finished"

Dsleep

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'sleep' instead of 'wait' does not wait for jobs.

Printing message before waiting.

The 'wait' command pauses until all jobs finish, then the echo prints a clear message.