How to Create Multi-Line String in Bash

1. Use here-document to Make Multi-Line String in Bash
2. Use Shell Variable to Make Multi-Line String in Bash
3. Use printf to Make Multi-Line String in Bash
4. Use echo With the -e Option to Make Multi-Line String in Bash
5. Use echo to Make Multi-Line String in Bash

This tutorial demonstrates different ways to print a multi-line string to a file in bash without putting extra space (indentation) by the use of here-document, shell variable, printf, echo, and echo with -e option.

Use here-document to Make Multi-Line String in Bash

Here-document provides an interactive way to input multi-line string into a file. The EOF is known as the Here Tag. The Here Tag tells the shell that you will input a multi-line string until the Here Tag since it acts as a delimiter. The << is used to set the Here Tag. The > is used for input redirection. It redirects the input to the specified file, output.txt, in our case.

cat << EOF > output.txt
> Hello
> World
> !
> EOF

Let us check the content of the output.txt file with the cat command.

cat output.txt

From the output, we see that every set of words has its own line, and there are no extra spaces.

Hello
World
!

Use Shell Variable to Make Multi-Line String in Bash

Here, we are using a shell variable named greet. We have assigned a multi-line string to greet.

greet="Hello
> ,
> wolrd
> !"

The command below gets the multi-line string in the shell variable, greet, and redirects it to the specified file, multiline.txt, using >.

echo "$greet" > multiline.txt

Check the content of the multiline.txt with the cat command.

cat multiline.txt

From the output, we see that every set of words has its own line, and there are no extra spaces.

Hello
,
wolrd
!

Use printf to Make Multi-Line String in Bash

We can use printf with the new line character and redirect the output to a file using >. The content in the file does not have extra spaces.

#!/bin/bash

printf "Every word is on a seperate line!\n"
printf "%s\n" "Hello" "," "World" "!" > multiline.txt

Output:

Every word is on a separate line!

Print out the content of multiline.txt with the cat command.

cat multiline.txt

From the output, we see that every set of words has its own line, and there are no extra spaces.

Hello
,
World
!

Use echo With the -e Option to Make Multi-Line String in Bash

The following bash script prints the words to multiline.txt without any extra spaces. The -e option enables the interpretation of escape characters in the variable greet.

#!/bin/bash

greet="Hello\n,\nWorld\n!"
echo -e $greet > multiline.txt

Print out the content of multiline.txt with the cat command

cat multiline.txt

From the output, we see that every set of words has its own line, and there are no extra spaces.

Hello
,
World
!

Use echo to Make Multi-Line String in Bash

The script below assigns a multi-line string to a variable named greet. Next, the content of the variable is redirected to the multiline.txt files using >. The quotes on the greet variable preserve the new lines.

#!/bin/bash

greet="Hello
,
World
!"
echo "$greet" > multiline.txt

Show content of multiline.txt with cat command.

cat multiline.txt

From the output, we see that every set of words has its own line, and there are no extra spaces.

Hello
,
World
!