Brace expansion ({1..10}) in Bash Scripting - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to print numbers from 1 to 10 using brace expansion.

Bash Scripting

echo [1]

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

A[1..10]

B(1..10)

C<1..10>

D{1..10}

Attempts:

3 left

💡 Hint

Common Mistakes

Using square brackets [] instead of curly braces.

Using parentheses () instead of curly braces.

Using angle brackets <> instead of curly braces.

Brace expansion uses curly braces with two numbers separated by two dots to generate a sequence.

2fill in blank

medium

Complete the code to create files named file1 to file10 using brace expansion.

Bash Scripting

touch file[1]

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

A{1..10}

B[1..10]

C(1..10)

D<1..10>

Attempts:

3 left

💡 Hint

Common Mistakes

Using square brackets instead of curly braces.

Using parentheses instead of curly braces.

Using angle brackets instead of curly braces.

Brace expansion with {1..10} generates numbers from 1 to 10 to create multiple files.

3fill in blank

hard

Fix the error in the code to print numbers 1 to 10 using brace expansion.

Bash Scripting

echo {1.[1]10}

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

A.

B...

C..

D,

Attempts:

3 left

💡 Hint

Common Mistakes

Using a single dot instead of two dots.

Using three dots or a comma instead of two dots.

Brace expansion requires two dots '..' between numbers to specify a range.

4fill in blank

hard

Fill both blanks to create a sequence of letters from a to j using brace expansion.

Bash Scripting

echo [1][2]

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

A[a..j]

B{a..j}

C{1..10}

D(a..j)

Attempts:

3 left

💡 Hint

Common Mistakes

Using square brackets or parentheses instead of curly braces.

Adding extra characters after the brace expansion.

Brace expansion with {a..j} generates letters from a to j. No extra characters needed after.

5fill in blank

hard

Fill the blank to create files named img01.jpg to img10.jpg using brace expansion.

Bash Scripting

touch img[1].jpg

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

A{01..10}

B1

Cjpg

D0

Attempts:

3 left

💡 Hint

Common Mistakes

Using {1..10} without leading zero padding.

Using incorrect brace expansion syntax.

Wrong file extension.

Brace expansion with {01..10} generates padded numbers 01 to 10 to create img01.jpg to img10.jpg.

Practice

1. What does the Bash brace expansion {1..5} produce when used in a command?

easy

A. A sequence of numbers: 1 2 3 4 5

B. A sequence of letters: a b c d e

C. A syntax error

D. A single string: {1..5}

Solution

1. Step 1: Understand brace expansion syntax

   The syntax {start..end} generates a sequence of numbers or letters from start to end.

2. Step 2: Apply to numbers 1 to 5

   Using {1..5} produces the numbers 1, 2, 3, 4, 5 separated by spaces.

3. Final Answer:

   A sequence of numbers: 1 2 3 4 5 -> Option A

4. Quick Check:

   Brace expansion {1..5} = 1 2 3 4 5 [OK]

Hint: Brace expansion {x..y} lists numbers or letters from x to y [OK]

Common Mistakes:

• Thinking it outputs letters for numbers
• Expecting a syntax error
• Assuming it outputs the literal string

2. Which of the following is the correct syntax to generate numbers from 3 to 7 using brace expansion in Bash?

easy

A. echo [3..7]

B. echo {3-7}

C. echo (3..7)

D. echo {3..7}

Solution

1. Step 1: Recall correct brace expansion syntax

   Brace expansion uses curly braces with two dots: {start..end}.

2. Step 2: Check each option

   Only echo {3..7} uses correct braces and dots. Others use wrong symbols like parentheses, brackets, or hyphens.

3. Final Answer:

   echo {3..7} -> Option D

4. Quick Check:

   Correct syntax uses curly braces and two dots [OK]

Hint: Use curly braces and two dots for sequences {start..end} [OK]

Common Mistakes:

• Using parentheses or brackets instead of braces
• Using a hyphen instead of two dots
• Missing braces entirely

3. What is the output of the following Bash command?

echo file{1..3}.txt

medium

A. file1.txt file2.txt file3.txt

B. file{1..3}.txt

C. file1 file2 file3.txt

D. file1.txt file2.txt file3

Solution

1. Step 1: Understand brace expansion with suffix

   The brace expansion {1..3} generates 1 2 3, and the suffix .txt is added to each.

2. Step 2: Combine parts

   Each expanded number is combined with 'file' prefix and '.txt' suffix, producing: file1.txt file2.txt file3.txt.

3. Final Answer:

   file1.txt file2.txt file3.txt -> Option A

4. Quick Check:

   Brace expansion with suffix repeats suffix for each number [OK]

Hint: Brace expansion repeats suffix/prefix for each number [OK]

Common Mistakes:

• Expecting literal braces in output
• Missing suffix on some items
• Mixing suffix placement

4. Identify the error in this Bash command:

echo {1..5..2}

medium

A. Outputs 1 2 3 4 5

B. Syntax error: too many dots

C. No error; outputs 1 3 5

D. Outputs nothing

Solution

1. Step 1: Understand brace expansion with step

   The syntax {start..end..step} is valid in Bash to generate sequences with a step.

2. Step 2: Apply to {1..5..2}

   This generates numbers starting at 1, stepping by 2, up to 5: 1, 3, 5.

3. Final Answer:

   No error; outputs 1 3 5 -> Option C

4. Quick Check:

   Brace expansion supports step with two dots between numbers [OK]

Hint: Brace expansion can include step: {start..end..step} [OK]

Common Mistakes:

• Thinking extra dots cause syntax error
• Expecting continuous sequence ignoring step
• Assuming no output for step usage

5. You want to create empty files named log1.txt through log10.txt using a single Bash command with brace expansion. Which command achieves this?

hard

A. touch log{1..10}

B. touch log{1..10}.txt

C. touch log{1..10}.txt.txt

D. touch log{1..10.txt}

Solution

1. Step 1: Understand the goal

   You want files named log1.txt, log2.txt, ..., log10.txt created.

2. Step 2: Use brace expansion with suffix

   The correct syntax is touch log{1..10}.txt, which expands to log1.txt, log2.txt, ..., log10.txt.

3. Step 3: Check other options

   touch log{1..10} omits the .txt suffix; touch log{1..10.txt} has invalid syntax with .txt inside braces; touch log{1..10}.txt.txt adds an extra .txt to each filename.

4. Final Answer:

   touch log{1..10}.txt -> Option B

5. Quick Check:

   Brace expansion with suffix creates all files at once [OK]

Hint: Use touch with brace expansion and suffix: touch name{1..n}.ext [OK]

Common Mistakes:

• Placing suffix inside braces incorrectly
• Adding extra suffixes
• Omitting suffix leading to wrong filenames