Brace expansion ({1..10}) in Bash Scripting - Practice Problems & Coding Challenges

Challenge - 5 Problems

💻 Command Output

intermediate

Output of simple brace expansion

What is the output of the following bash command?

echo {1..5}

Bash Scripting

echo {1..5}

A 1,2,3,4,5

B {1..5}

C 1 2 3 4 5 6

D 1 2 3 4 5

💡 Hint

Brace expansion generates a sequence of numbers separated by spaces.

The brace expansion {1..5} generates numbers from 1 to 5 separated by spaces when echoed.

💻 Command Output

intermediate

Brace expansion with step value

What is the output of this bash command?

echo {1..10..3}

Bash Scripting

echo {1..10..3}

A 1 4 7

B 1 4 7 10

C 1 3 6 9

D 1 2 3 4 5 6 7 8 9 10

💡 Hint

The third number in brace expansion is the step size.

The sequence starts at 1, increments by 3, and stops at or before 10: 1,4,7,10.

📝 Syntax

advanced

Identify invalid brace expansion syntax

Which of the following is NOT a valid brace expansion in bash?

A echo {5..1}

B echo {1..10..2}

C echo {1..10..0}

D echo {a..z}

💡 Hint

Step value cannot be zero in brace expansion.

A step value of zero is invalid and causes an error in bash brace expansion.

💻 Command Output

advanced

Output of nested brace expansion

What is the output of this bash command?

echo file{1..3}_{a..b}.txt

Bash Scripting

echo file{1..3}_{a..b}.txt

A file1_a.txt file1_b.txt file2_a.txt file2_b.txt file3_a.txt file3_b.txt

B file1_a.txt file2_b.txt file3_a.txt

C file{1..3}_{a..b}.txt

D file1_a.txt file1_b.txt file2_a.txt file3_b.txt

💡 Hint

Brace expansions combine all possible pairs from each set.

The command expands numbers 1 to 3 and letters a to b, combining each number with each letter.

🚀 Application

expert

Count files created by brace expansion

If you run this command:

touch log_{01..10}_{a..c}.txt

How many files will be created?

Bash Scripting

touch log_{01..10}_{a..c}.txt

A 30

B 33

C 20

D 13

💡 Hint

Multiply the count of numbers by the count of letters.

There are 10 numbers (01 to 10) and 3 letters (a to c), so 10 * 3 = 30 files.