Appending to files (>>) in Bash Scripting - Practice Problems & Coding Challenges

Challenge - 5 Problems

💻 Command Output

intermediate

What is the content of the file after appending?

You have a file named log.txt containing:

Line1

What will be the content of log.txt after running this command?

echo "Line2" >> log.txt

A Line1\n\nLine2

B Line2

C Line1\nLine2

D Line1

💡 Hint

Appending adds new content after existing content without removing it.

The >> operator adds the new line after the existing content. So the file will have the original 'Line1' and then 'Line2' on the next line.

💻 Command Output

intermediate

What happens when appending with a missing file?

If notes.txt does not exist, what will be the content of notes.txt after running?

echo "Start" >> notes.txt

A Nothing happens, file remains missing

B Error: notes.txt not found

C File created but empty

D File created with content: Start

💡 Hint

Appending creates the file if it does not exist.

The >> operator creates the file if it does not exist and then writes the content.

📝 Syntax

advanced

Which command correctly appends multiple lines to a file?

You want to append these two lines to data.txt:

First line
Second line

Which command will do this correctly?

A echo "First line" >> data.txt && echo "Second line" >> data.txt

B echo "First line\nSecond line" >> data.txt

C echo -e "First line\nSecond line" >> data.txt

D echo "First line" > data.txt && echo "Second line" >> data.txt

💡 Hint

Appending multiple lines can be done by multiple echo commands with >>.

Option A appends each line separately without overwriting. Option A overwrites the file first, so only second line remains. Option A does not interpret \n as newline. Option A depends on echo -e support which is not portable.

🔧 Debug

advanced

Why does this append command overwrite the file instead of appending?

A user runs:

echo "New entry" > file.txt >> file.txt

What is the problem with this command?

A The command syntax is invalid and causes an error

B The > operator runs first and overwrites the file before >> appends

C The >> operator overwrites the file, not appends

D The echo command ignores redirection operators

💡 Hint

Order of redirection operators matters in bash.

In bash, > truncates the file immediately, then >> appends. Since > runs first, the file is overwritten before appending.

🚀 Application

expert

How to append output of a command to a file safely in a script?

You want to append the output of date command to timestamps.log inside a bash script. Which line is the best to do this safely and avoid overwriting?

A date >> timestamps.log

B echo $(date) >> timestamps.log && > timestamps.log

C echo $(date) > timestamps.log

D date > timestamps.log

💡 Hint

Appending means adding without removing existing content.

Option A appends the output of date to the file. Option A overwrites. Option A overwrites. Option A appends then truncates, so file ends empty.