Substring extraction (${var:offset:length}) in Bash Scripting - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to extract the substring 'world' from the variable.

Bash Scripting

text="hello world"
sub=${text:[1]:5}
echo "$sub"

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

A1

B0

C5

D6

Attempts:

3 left

💡 Hint

Common Mistakes

Using offset 0 or 1 extracts the wrong part of the string.

Forgetting that offset counts from zero.

The substring extraction syntax ${var:offset:length} starts at offset 6 to get 'world' from 'hello world'.

2fill in blank

medium

Complete the code to extract the first 4 characters from the variable.

Bash Scripting

filename="report2024.txt"
prefix=${filename:[1]:4}
echo "$prefix"

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

A4

B1

C0

D5

Attempts:

3 left

💡 Hint

Common Mistakes

Starting at offset 1 misses the first character.

Using offset equal to length extracts nothing.

Offset 0 starts at the beginning, so ${filename:0:4} extracts 'repo'.

3fill in blank

hard

Fix the error in the code to correctly extract '2024' from the filename.

Bash Scripting

filename="report2024.txt"
year=${filename:[1]:4}
echo "$year"

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

A7

B6

C4

D5

Attempts:

3 left

💡 Hint

Common Mistakes

Using offset 7 or 4 extracts wrong parts.

Confusing offset with length.

The year '2024' starts at offset 6 in 'report2024.txt', so ${filename:6:4} extracts it correctly.

4fill in blank

hard

Fill both blanks to extract 'script' from the variable.

Bash Scripting

word="bashscript"
sub=${word:[1]:[2]
echo "$sub"

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

A4

B6

C7

D5

Attempts:

3 left

💡 Hint

Common Mistakes

Using wrong offset or length extracts incorrect substring.

Mixing up offset and length values.

The substring 'script' starts at offset 4 and has length 6 in 'bashscript'.

5fill in blank

hard

Fill both blanks to extract 'log' from the filename variable.

Bash Scripting

filename="system.log.2024"
sub=${filename:[1]:[2]
echo "$sub"

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

A7

B3

C4

D6

Attempts:

3 left

💡 Hint

Common Mistakes

Using offset 6 or 4 extracts wrong substring.

Using length 4 extracts extra characters.

The substring 'log' starts at offset 7 and has length 3 in 'system.log.2024'.