4 Best Fixes for “syntax error near unexpected token ‘newline'” in Linux

Written by

Ojash

Reviewed by

Akshat

Last updated: July 24, 2024

Expert verified

Running into a “syntax error near unexpected token ‘newline'” in Linux can be really frustrating, but there’s a solution. In this post, I’ll help you understand what causes this error and how you can fix it. We’ll look at common mistakes like missing quotes and unclosed braces. Plus, I’ll show you how to use tools like ShellCheck, Vim, and Sublime Text to troubleshoot these errors. By the end, you’ll know how to prevent these issues and keep your scripts running smoothly.

Common Causes of “syntax error near unexpected token ‘newline'” in Linux

The “syntax error near unexpected token ‘newline'” is a common issue in Linux shell scripting. It typically results from simple mistakes in the script syntax. Understanding these common causes can help you quickly identify and fix the error.

1. Missing or Misplaced Quotation Marks

Quotation marks (', ") are used to group words together as a single argument. If you forget to close a quote or place it incorrectly, the shell can’t interpret the command properly.

Example:

 echo "Hello World    
 
 //(missing closing quote)

Solution: Ensure every opening quote has a corresponding closing quote.

• Correction:

echo "Hello World"

2. Unclosed Parentheses or Braces

Parentheses (), braces {}, and brackets [] are used in various shell constructs like loops and conditionals. If you start one but don’t close it, the shell can’t complete the command.

Example:

if [ $x -eq 1 ] ( echo "x is 1" 
//(missing closing parenthesis)

Solution: Always ensure that for every opening parenthesis, brace, or bracket, there is a corresponding closing one.

• Correction:

if [ $x -eq 1 ]; then echo "x is 1"; fi

3. Improper Use of Special Characters

Special characters like ;, &, |, and > have specific meanings in the shell. Incorrect placement or missing arguments can cause syntax errors.

Example:

ls -l | 
//(pipe symbol with no command after it)

Solution: Ensure all special characters are used correctly and followed by the necessary arguments or commands.

• Correction:

ls -l | grep "file"

4. Incorrect Use of Variables

Variables in shell scripts are used to store data. Incorrect declaration or use can lead to errors. Variables must be properly initialized before use.

Example:

echo $name 
//(if name is not defined)

Solution: Always initialize variables before use.

• Correction:

name="John"; echo $name

5. Incomplete Commands

Commands need to be complete for the shell to execute them. If you start a command but don’t finish it, the shell will expect more input and throw an error when it reaches the end of the line.

Example:

echo "Hello 
//(incomplete command without ending)

Solution: Ensure every command is complete.

• Correction:

echo "Hello"

How to Fix “syntax error near unexpected token ‘newline'” in Linux

Let’s explore each method in detail here.

1. Check for Syntax Errors and Typos

The first step in fixing the “syntax error near unexpected token ‘newline'” error is to check for syntax errors and typos in a text editor. To review the command or script you are trying to execute, you should:

1. Use the following command in the Terminal app to open the script file in the Nano editor:

nano script.sh

2. This command either opens or creates a shell script file called script.sh using the lightweight text editor Nano in the Terminal.

3. Now, in the Nano editor, review the script for syntax errors and typos.

4. Correct any errors you find and save the file by pressing Ctrl + O followed by Ctrl + X.

2. Check File Permissions

If the “syntax error near unexpected token ‘newline'” error persists after checking for syntax errors and typos, the next step is to check the file permissions. Ensure that the file has the correct permissions to be executed. To do this, follow these steps:

1. Run the following command in the Terminal app to check the file permissions:

ls -l script.sh

2. Check the file permissions in a long format. Look for any issues with the permissions, such as the file being read-only or not executable.

3. If necessary, use the following command to modify the permissions:

chmod +x script.sh

3. Check for Incompatible Shell Versions

Sometimes, the “syntax error near unexpected token ‘newline'” error may be caused by incompatible shell versions. If that’s the case, here’s what you need to do:

1. Check the shell version you’re using by running the following command:

echo $0

2. Ensure that the version you’re using is compatible with the script or command you’re running.

3. If not, switch to a compatible shell version. To change the shell version, use the following command:

chsh -s /bin/zsh

4. Once you’ve switched to a compatible shell, reboot your system with the following command:

sudo reboot

5. Now, try running the script or command again to see if the error has been resolved.

4. Use Visual Aids to Trace this Error 

If you’re still experiencing the “syntax error near unexpected token ‘newline'” error after checking for syntax errors, file permissions, and shell compatibility, consider using visual aids to troubleshoot. This can include using debuggers, tracing, or logging to help identify the cause of the error. To use a debugger, here’s what you need to do:

1. Launch the Terminal app and execute the following command:

bash -x script.sh

2. This command runs the script in debug mode, displaying each command as it is executed. Use this information to identify the source of the error and make any necessary corrections.

3 Top Third-Party Tools for Linux Syntax Errors

Several third-party tools can help you troubleshoot the “syntax error near unexpected token ‘newline'” error in Linux. To test the three popular tools, let’s create a sample script using this code:

#!/bin/bash

for i in {1..5}
do
    echo "Number: $i
done

Just copy-paste the code into a text file using the gedit app or any other text editor in your Linux distro. Alternatively, you can create this script using the Nano editor within the Terminal interface with the nano sample_script.sh command.

Once you’ve created this script with the provided code, you’ll notice that there is a missing closing double-quote in the echo statement. It is done on purpose to cause a syntax error. So, to experience how the following three popular tools handle the syntax errors in the script :

1. ShellCheck

ShellCheck is a powerful, open-source static analysis tool that analyzes shell scripts for syntax errors, common mistakes, and potential issues. It offers detailed suggestions for improving the script’s quality and robustness. ShellCheck supports various shell dialects, including Bash, Dash, and Ksh. Here’s how you can use this tool to check for syntax errors in the script:

1. Install shellcheck by executing:

sudo apt install shellcheck

2. Once installed, run the command below to open the script:

shellcheck sample_script.sh

3. Now, you’ll see the following error report.

4. Once you’ve resolved the syntax error in your code, run the shellcheck and then the script using ./script-name.sh. Your output should look like this:

2. Vim

Vim is a highly configurable and extensible text editor that supports shell scripts and other scripting languages. It offers syntax highlighting, auto-indentation, and various plugins to improve the editing experience. Vim’s command-based interface allows for efficient navigation and editing of code, making it easier to identify and fix syntax errors quickly. To check out this tool for syntax errors in a code, follow these steps:

1. Execute the code below in the Terminal window to install Vim.

sudo apt-get install vim

2. Next, open the script using this command line:

vim sample_script.sh

3. Observe the syntax highlighting indicating the missing closing double-quote.

4. You will see the following output in Vim after fixing the syntax error in your code.

3. Sublime Text

Sublime Text is a sophisticated text editor for code, markup, and prose that supports shell scripts and other scripting languages. It features a built-in package manager for installing and managing plugins, syntax highlighting, and auto-completion. Sublime Text’s multiple cursors and powerful search capabilities make editing and troubleshooting scripts efficient. Follow the steps below to experience syntax error detection with this tool:

1. In the Terminal window, enter the Sublime repository key by entering the following command:

wget -qO - https://download.sublimetext.com/sublimehq-pub.gpg | sudo apt-key add -

2. Add the Sublime repository to the system’s APT sources list with the following command:

echo "deb https://download.sublimetext.com/ apt/stable/" | sudo tee /etc/apt/sources.list.d/sublime-text.list

3. Update the package list by running:

sudo apt-get update

4. Now, install Sublime by running the command:

sudo apt-get install sublime-text

5. Open the sample script using the following command:

subl sample_script.sh

6. Once the Sublime Text editor opens, observe the syntax highlighting indicating the missing closing double-quote.

7. After fixing the syntax error of the code in the Sublime Text editor, you see the following output:

7 Best Practices to Avoid Newline Syntax Errors in Linux

To avoid encountering the “syntax error near unexpected token ‘newline'” error in the future, it’s essential to follow some best practices. These include:

• 🔍 Double-check syntax and spelling: Syntax errors often occur due to typos, incorrect syntax, or missing punctuation. Double-checking your commands or scripts before executing them can prevent errors from occurring. Consider using a text editor with syntax highlighting to highlight syntax errors before running the command or script.
• 💻 Use compatible shell versions: Different shell versions may have different syntax, which can lead to unexpected errors. Therefore, it’s crucial to use compatible shell versions when running scripts or executing commands. Check the version of the shell with echo $SHELL --version before running a script or command to avoid errors.
• 🛠️ Use debuggers or other tools: Debuggers or other tools can help troubleshoot errors by identifying the line of code that causes the error. Some of the commonly used debuggers for shell scripting include Bash Debugger and ShellCheck script analysis tools. These tools can help identify syntax errors and other errors that may cause unexpected errors.
• 🗃️ Use source control: Implement source control (e.g., Git) to manage script/command changes, track modifications, and revert to previous versions when needed. This can be especially useful if you experience unexpected errors after making changes to a script or command.
• 🔒 Check file permissions: Sometimes, permissions can cause unexpected errors like “syntax error near unexpected token ‘newline'” in Linux, especially when executing a command or script. So, ensuring the file has the correct permissions set before executing it is important. Use chmod +x script.sh to set the correct permissions.
• 🧪 Test scripts/commands: Before running a script or executing a command, it’s crucial to test it thoroughly. This can include testing different scenarios and inputs to ensure the script or command works as intended. Moreover, by testing the script or command, you can identify and fix potential errors before they occur.
• 📝 Track/document changes: Keep track of script and command modifications by adding comments, maintaining a change log, or creating detailed documentation. This practice will help you in identifying and resolving errors in the future.

Wrap-Up

To wrap things up, fixing the “syntax error near unexpected token ‘newline'” in Linux involves checking for syntax errors and typos, ensuring correct file permissions, and verifying shell compatibility. Using visual aids and tools like ShellCheck, Vim, and Sublime Text can help you pinpoint and resolve errors.

If you want to explore more, here are some suggested reads:

• Learn about using ‘bash set -x’ for debugging, which can show each command before execution, making it easier to spot where things go wrong.
• Discover how to make your Bash scripts executable, ensuring they run smoothly without permission issues.
• Explore the use of ‘cat EOF’ for handling multi-line strings in Bash, simplifying the management of long text blocks within your scripts.

Frequently Asked Questions