tr (translate characters) in Linux CLI - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to translate all lowercase letters to uppercase using tr.

Linux CLI

echo "hello world" | tr [1]

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

A'a-z' 'A-Z'

BA-Z a-z

C0-9 a-z

Da-z 0-9

Attempts:

3 left

💡 Hint

Common Mistakes

Swapping the order of character sets.

Using numbers instead of letters.

Forgetting to quote the character sets.

The tr command translates characters from the first set to the second set. To convert lowercase to uppercase, use tr 'a-z' 'A-Z'.

2fill in blank

medium

Complete the code to delete all digits from the input using tr.

Linux CLI

echo "abc123def456" | tr -d [1]

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

Aa-z

B0-9

CA-Z

D[:alpha:]

Attempts:

3 left

💡 Hint

Common Mistakes

Deleting letters instead of digits.

Using uppercase letters as the set.

Not using the -d option.

The -d option deletes characters. To delete digits, use 0-9.

3fill in blank

hard

Fix the error in the code to replace all spaces with underscores using tr.

Linux CLI

echo "hello world" | tr [1]

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

A" _"

B"_ "

C" " "_"

D"_" " "

Attempts:

3 left

💡 Hint

Common Mistakes

Swapping the order of characters.

Missing quotes around characters.

Using the wrong characters inside quotes.

The correct syntax is tr ' ' '_' to replace spaces with underscores. Quotes are needed around each character set.

4fill in blank

hard

Fill both blanks to create a command that squeezes multiple spaces into one space and then deletes all digits.

Linux CLI

echo "a  b   c123" | tr [1] | tr -d [2]

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

A-s ' '

B0-9

Ca-z

D-d ' '

Attempts:

3 left

💡 Hint

Common Mistakes

Using -d instead of -s for squeezing.

Deleting letters instead of digits.

Incorrect order of commands.

Use tr -s ' ' to squeeze spaces and tr -d 0-9 to delete digits.

5fill in blank

hard

Fill all three blanks to create a command that converts lowercase to uppercase, deletes digits, and replaces spaces with underscores.

Linux CLI

echo "hello 123 world" | tr [1] | tr -d [2] | tr [3]

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

A"a-z" "A-Z"

B0-9

C" " "_"

D"A-Z" "a-z"

Attempts:

3 left

💡 Hint

Common Mistakes

Swapping uppercase and lowercase sets.

Forgetting to delete digits.

Incorrect quoting of characters.

First, convert lowercase to uppercase with tr 'a-z' 'A-Z'. Then delete digits with tr -d 0-9. Finally, replace spaces with underscores using tr ' ' '_'.