Bash Replace Space with Newline

If you have multiple consecutive spaces in the string, use the last solution, the for loop. You can use any of the following solutions if you have a multiline string.

Using tr Command

Use the tr command to replace space with newline in bash.

We initialized the text variable with a sample string. Next, we piped the output of the echo command to the tr command, which translated (replaced) space (' ') with newline (\n).

We captured the output of the echo "$text" | tr ' ' '\n' command using substitution syntax ($(...)) and assigned to the new_text variable. Finally, we used the echo command to print the new_text variable’s value on the bash console.

Using awk Command

Use the awk command to replace space with newline in bash.

This code snippet is similar to the previous example; however, we piped the echo command output to the awk command this time. The awk is used for text processing. It operates per line by default, but we can customize it to work with fields and records (lines) using special actions and patterns.

In the above example, we used the awk command to replace space with a newline. How? For that, we used the -v option to set the record separator variable (RS) to a space character (" "). By default, the awk takes the newline character as the value of the RS variable.

So, modifying the RS to a space character meant that each space-separated word would become a separate record for processing. For each record, the print command was executed to print the current record, followed by a new line. This effectively replaced spaces with newlines in the output.

Alternatively, we can use the following solution:

Here, we used the gsub, an AWK function to globally substitute all occurrences of a space character (/ /) in the text with a newline character ("\n").

Using sed Command

Use the sed command to replace space with newline in bash.

We used the sed command, which is used to process and transform text, typically used for performing text substitution, deletion, insertion and more.

In the above example, we used the sed command to substitute text. For that, we wrote the sed command sequence enclosed in single quotes; for instance, 's/ /\n/g'. This sed sequence instructed to perform a substitution operation on the input text.

The sequence of the sed command was comprised of various components; let’s learn them below:

• s (stands for substitute) – It told the sed to find and replace.

• / (delimiter character) – It separated the different parts of the sed command: pattern to search for, replacement, and any flags.

• space (between first and second /): This was the pattern to search for. In our case, it was a single-space character.

• \n (newline) – It was the replacement part; when the pattern (space) was found in the input, it would be replaced with a newline.

• g (stands for global) – This flag told sed to perform the replacement globally, meaning all occurrences of the pattern in a line would be replaced with the newline character, not just the first occurrence.

This effectively split the input text into separate lines wherever there was a space character.

Using Parameter Expansion

Use parameter expansion to replace space with newline in bash.

This example is similar to the previous ones, but we used parameter expansion this time. The parameter expansion ({text// /$'\n'}) took the value of the text variable, found all occurrences of a space character, and replaced them with a newline character. How? Following is a brief explanation of each component:

• ${...} was the basic syntax of parameter expansion; here, ... meant anything that you want to accomplish; for instance, text// /$'\n' in our case.

• // was a pattern-matching operator used in parameter expansion. When used as ${parameter//pattern/string}, it matched all occurrences of the provided pattern in the parameter (in this case, the variable text) and replaced them with the given string.

• ' ' was the pattern we searched for in the text variable. It was a single-space character.

• $'\n' was an ANSI-C quoted string representing a newline character (\n). The $'...' syntax interpreted backslash escapes in bash, so $'\n' was replaced with an actual newline character.

This was how we replaced space with newline in the text.

Using for Loop

Use the for loop to replace space with newline in bash.

We used a for loop in the above example to iterate over the $text. In each iteration, we concatenated the $new_text, $current_word, and a newline (\n) as "$new_text$current_word\n" and assigned its value to the new_text variable.

Once the loop was over, we used the echo command with the -e option to print the value of the new_text variable on the bash console.

Note that the -e option was used to interpret backslash escapes in the given string (in this case, new_text), allowing us to include special characters with specific meanings; for example, \n means a new line.