Escape characters (\) in Bash Scripting - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to print a double quote inside the string.

Bash Scripting

echo "She said, \[1]Hello\[1]"

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

A\

B'

C"

D$

Attempts:

3 left

💡 Hint

Common Mistakes

Using single quotes instead of escaping double quotes.

Not escaping the double quotes, causing syntax errors.

To print double quotes inside a double-quoted string in bash, you escape them with a backslash (\").

2fill in blank

medium

Complete the code to print a newline character using echo.

Bash Scripting

echo -e "First line[1]Second line"

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

A\n

B\\

C\r

D\t

Attempts:

3 left

💡 Hint

Common Mistakes

Using \t which inserts a tab instead of a newline.

Not using -e option, so escape sequences are not interpreted.

The escape sequence \n inserts a newline in the output when used with echo -e.

3fill in blank

hard

Fix the error in the code to correctly print a backslash character.

Bash Scripting

echo "This is a backslash: [1]"

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

A/

B\\

C"

D\

Attempts:

3 left

💡 Hint

Common Mistakes

Using a single backslash which escapes the next character.

Using a forward slash instead of backslash.

To print a single backslash, you need to escape it with another backslash, so use \\.

4fill in blank

hard

Fill both blanks to print a tab and a newline in the output.

Bash Scripting

echo -e "Column1[1]Column2[2]End"

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

A\t

B\n

C\r

D\\

Attempts:

3 left

💡 Hint

Common Mistakes

Mixing up \r (carriage return) with \n (newline).

Not using -e option so escapes are not processed.

Use \t for tab and \n for newline inside echo -e to format output.

5fill in blank

hard

Fill all three blanks to create a string with a literal dollar sign, a double quote, and a backslash.

Bash Scripting

echo "Price: [1]100, Quote: [2]Hello[2], Path: C:[3]Users"

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

A\$

B\"

C\\

D\n

Attempts:

3 left

💡 Hint

Common Mistakes

Not escaping the dollar sign causing variable expansion.

Using single backslash for backslash printing.

Not escaping double quotes causing syntax errors.

Escape $ with \$, double quote with \" and backslash with \\ inside double quotes.

Practice

1. What does the backslash (\) do in a bash command?

easy

A. It repeats the previous command

B. It comments out the rest of the line

C. It escapes special characters to treat them as normal text

D. It runs the command in the background

Solution

1. Step 1: Understand the role of backslash in bash

   The backslash is used to escape special characters so they are treated literally.

2. Step 2: Compare with other options

   Comments start with #, background runs use &, and repeating commands is done with !!, so these are incorrect.

3. Final Answer:

   It escapes special characters to treat them as normal text -> Option C

4. Quick Check:

   Escape character = D [OK]

Hint: Backslash means "escape next character" in bash [OK]

Common Mistakes:

• Confusing backslash with comment symbol (#)
• Thinking backslash runs commands in background (&)
• Assuming backslash repeats commands

2. Which of the following is the correct way to escape a space in a bash filename?

easy

A. my file.txt

B. my\ file.txt

C. my file\.txt

D. my/file.txt

Solution

1. Step 1: Identify how to escape spaces in bash

   Spaces must be escaped with a backslash to be treated as part of the filename.

2. Step 2: Check each option

   my\ file.txt uses backslash before space correctly. my file.txt has unescaped space, C escapes dot incorrectly, D uses slash which is a directory separator.

3. Final Answer:

   my\ file.txt -> Option B

4. Quick Check:

   Escape space with \ = B [OK]

Hint: Use \ before spaces to keep filename intact [OK]

Common Mistakes:

• Not escaping spaces causing command errors
• Escaping wrong characters like dot instead of space
• Using slash instead of backslash for spaces

3. What is the output of this bash command?

echo Hello\ World\!

medium

A. Hello World!

B. Hello\ World\!

C. HelloWorld!

D. Hello World\!

Solution

1. Step 1: Understand escaping in echo command

   Backslash escapes spaces and exclamation mark, so they appear as normal characters.

2. Step 2: Interpret the output

   The command prints: Hello World! with spaces and exclamation mark shown literally.

3. Final Answer:

   Hello World! -> Option A

4. Quick Check:

   Escaped spaces and ! print normally = C [OK]

Hint: Backslash shows special chars literally in output [OK]

Common Mistakes:

• Thinking backslash prints as literal \
• Ignoring escaped spaces causing joined words
• Confusing output with unescaped exclamation

4. You want to print the path /home/user/My Documents in bash. Which command fixes the error caused by the space?

medium

A. echo /home/user/My\ Documents

B. echo /home/user/My Documents

C. echo /home/user/My\Documents

D. echo /home/user/My\ Documents\

Solution

1. Step 1: Identify the problem with spaces in paths

   Spaces separate arguments, so they must be escaped or quoted to be treated as one string.

2. Step 2: Check which command escapes the space correctly

   echo /home/user/My\ Documents escapes the space with backslash correctly. echo /home/user/My Documents causes error, C escapes wrong place, D adds extra backslash at end.

3. Final Answer:

   echo /home/user/My\ Documents -> Option A

4. Quick Check:

   Escape space in path = A [OK]

Hint: Escape spaces in paths with \ or use quotes [OK]

Common Mistakes:

• Not escaping spaces causing command errors
• Escaping wrong characters or missing escape
• Adding unnecessary trailing backslash

5. You want to create a bash script that prints the exact string: Path is C:\Program Files\App. Which command inside the script will produce this output correctly?

hard

A. echo Path is C:\\Program Files\\App

B. echo 'Path is C:\Program Files\App'

C. echo Path is C:\Program Files\App

D. echo "Path is C:\\Program Files\\App"

Solution

1. Step 1: Understand escaping backslashes in bash strings

   Backslash is special, so to print one backslash inside double quotes, use two backslashes \\.

2. Step 2: Analyze each option's output

   echo "Path is C:\\Program Files\\App" doubles backslashes inside double quotes, printing correctly. echo 'Path is C:\Program Files\App' uses single quotes but backslash is literal, so output misses doubling. echo Path is C:\Program Files\App and D do not escape spaces or backslashes properly.

3. Final Answer:

   echo "Path is C:\\Program Files\\App" -> Option D

4. Quick Check:

   Double backslash inside quotes prints one backslash = A [OK]

Hint: Double backslash inside "" prints one backslash [OK]

Common Mistakes:

• Using single backslash inside double quotes
• Not escaping backslash at all
• Confusing single and double quotes effects