Logical operators (-a, -o, !) in Bash Scripting - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to check if the file 'data.txt' exists and is readable.

Bash Scripting

if [ -e data.txt [1] ]; then echo "File exists and is readable"; fi

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

A-a -r data.txt

B-a -e data.txt

C-a -f data.txt

D-o -r data.txt

Attempts:

3 left

💡 Hint

Common Mistakes

Using '-o' instead of '-a' for AND operation.

Forgetting to include the file test after '-a'.

Using '-f' instead of '-r' when checking readability.

The '-a' operator means AND, so '-a -r data.txt' checks if the previous condition (file exists with '-e') and the file is readable are both true.

2fill in blank

medium

Complete the code to check if the variable 'count' is either 0 or 10.

Bash Scripting

if [ "$count" -eq 0 [1] "$count" -eq 10 ]; then echo "Count is 0 or 10"; fi

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

A==

B-a

C-o

D!

Attempts:

3 left

💡 Hint

Common Mistakes

Using '-a' which means AND instead of OR.

Using '==' which is not valid in this context.

Using '!' which negates a condition.

The '-o' operator means OR, so it checks if either condition is true.

3fill in blank

hard

Fix the error in the code to check if the directory 'logs' does NOT exist.

Bash Scripting

if [ [1] -e logs ]; then echo "Logs directory missing"; fi

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

A-z

B-o

C-a

D!

Attempts:

3 left

💡 Hint

Common Mistakes

Using '-o' or '-a' which are logical AND/OR, not negation.

Using '-z' which checks for empty strings, not existence.

The '!' operator negates the test, so '! -e logs' means the file or directory does NOT exist.

4fill in blank

hard

Complete the code to check if the file 'config.cfg' exists AND is NOT empty.

Bash Scripting

if [ -e config.cfg [1] -s config.cfg ]; then echo "Config file exists and is not empty"; fi

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

A-a

B-o

Attempts:

3 left

💡 Hint

Common Mistakes

Using '-o' which means OR instead of AND.

Confusing '-s' (non-empty) with empty check; '! -s' would be for empty or non-existent.

Use '-a' for AND to combine the existence check ('-e') and the non-empty check ('-s' means size greater than zero).

5fill in blank

hard

Fill all three blanks to create a condition that checks if variable 'user' is NOT 'admin' AND file 'access.log' exists OR variable 'mode' equals 'debug'.

Bash Scripting

if [ ! "$user" = [1] [2] -e access.log [3] "$mode" = "debug" ]; then echo "Condition met"; fi

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

A"admin"

B-a

C-o

D"root"

Attempts:

3 left

💡 Hint

Common Mistakes

Using wrong strings for user comparison.

Mixing up '-a' and '-o' operators.

Not quoting variables properly.

The condition uses '!' to negate user='admin', '-a' for AND with file existence, and '-o' for OR with mode='debug'.