Writing to files (echo, printf) in Bash Scripting - Cheat Sheet & Quick Revision

Recall & Review

beginner

What does the command echo "Hello" > file.txt do in bash?

It writes the text "Hello" into the file named file.txt. If the file exists, it replaces its content. If not, it creates the file.

beginner

How do you append text to a file using echo?

Use the append operator >> like echo "More text" >> file.txt. This adds the text at the end without deleting existing content.

intermediate

Why might you use printf instead of echo for writing to files?

printf gives more control over formatting, like adding new lines, tabs, or controlling number formats, which echo may handle inconsistently across systems.

beginner

What is the difference between echo "text" > file.txt and echo "text" >> file.txt?

The first command overwrites the file with "text". The second command adds "text" to the end of the file without removing existing content.

intermediate

How can you write multiple lines to a file using printf?

Use printf with newline characters, for example: printf "Line1\nLine2\n" > file.txt writes two lines into the file.

Which operator is used to append text to a file in bash?

A >

B <

C |

D >>

The operator >> appends text to the end of a file without overwriting existing content.

What will echo "Hello" > file.txt do if file.txt already contains text?

A Overwrite the file with "Hello"

B Show an error

C Delete the file

D Add "Hello" at the end

The > operator overwrites the file content with the new text.

Which command gives more control over formatting when writing to files?

A echo

B cat

C printf

D ls

printf allows precise formatting like newlines and tabs.

How do you write multiple lines to a file using echo?

A echo "Line1" > file.txt; echo "Line2" >> file.txt

B All of the above

C echo "Line1" >> file.txt; echo "Line2" >> file.txt

D echo -e "Line1\nLine2" > file.txt

All these methods can write multiple lines, but some require multiple commands.

What does the command printf "Hello\nWorld" > file.txt do?

A Writes 'Hello' and 'World' on two separate lines

B Writes 'Hello World' on one line

C Appends 'Hello' and 'World' to the file

D Shows an error

The \n creates a new line, so 'Hello' and 'World' appear on separate lines.

Explain how to write and append text to a file using bash commands.

Think about how you save notes in a notebook: writing fresh or adding more.

Describe when and why you would use printf instead of echo for writing to files.

Consider needing exact layout or special characters in your text.