Anchors (^, $) in Bash Scripting - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to match lines that start with 'Hello'.

Bash Scripting

grep '[1]Hello' file.txt

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

A*

B$

C^

D.

Attempts:

3 left

💡 Hint

Common Mistakes

Using $ which matches the end of a line instead of the start.

Using * which matches zero or more of the previous character.

Using . which matches any single character.

The caret (^) anchor matches the start of a line, so '^Hello' matches lines starting with 'Hello'.

2fill in blank

medium

Complete the code to match lines that end with 'world'.

Bash Scripting

grep 'world[1]' file.txt

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

A$

B^

C*

D.

Attempts:

3 left

💡 Hint

Common Mistakes

Using ^ which matches the start of a line instead of the end.

Using * which matches zero or more of the previous character.

Using . which matches any single character.

The dollar sign ($) anchor matches the end of a line, so 'world$' matches lines ending with 'world'.

3fill in blank

hard

Fix the error in the grep pattern to match lines that start with 'Error' and end with '!'.

Bash Scripting

grep '[1]Error.*![2]' log.txt

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

A$

B^

C*

D.

Attempts:

3 left

💡 Hint

Common Mistakes

Not using ^ at the start to anchor the pattern.

Confusing * and . with anchors.

Missing the $ at the end to anchor the line end.

To match lines starting with 'Error' and ending with '!', the pattern should be '^Error.*!$'. Use ^ (B) for BLANK_1 and $ (A) for BLANK_2.

4fill in blank

hard

Fill both blanks to create a grep pattern that matches lines starting with 'Start' and ending with 'End'.

Bash Scripting

grep '[1]Start.*End[2]' data.txt

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

A^

B$

C*

D.

Attempts:

3 left

💡 Hint

Common Mistakes

Using * or . as anchors which are incorrect.

Forgetting to anchor the end with $.

Using anchors in the wrong positions.

The caret (^) anchors the start of the line and the dollar sign ($) anchors the end. Together they ensure the line starts with 'Start' and ends with 'End'.

5fill in blank

hard

Fill all three blanks to create a grep pattern that matches lines starting with 'ID' followed by digits and ending with 'OK'.

Bash Scripting

grep -E '[1]ID[2][0-9][3]OK$' records.txt

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

A^

B+

C*

D?

Attempts:

3 left

💡 Hint

Common Mistakes

Not anchoring the start with ^.

Using ? which means zero or one instead of * or +.

Misplacing the anchors.

The caret (^) anchors the start. With -E, + quantifies the 'D' to one or more (ensuring starts with 'ID'), [0-9]* matches zero or more digits, ending with OK$.