Understanding the ZSH “Bad Assignment” Errors: How to Fix and Prevent Them

ZSH has been a revolution to the terminal usage for quite a while now. With its simplistic and intuitive features and scripting language, it is not hard to see why ZSH has become so compelling. However, one of the things that you will notice when you use ZSH for scripting is the level of strictness that it has when it comes to the rules. Unlike other languages such as Bash, JavaScript, etc. where you get away with a flawed syntax (at the expense of logic), ZSH does not allow you to violate these rules.

Therefore, if you attempt to violate the ZSH syntax and variable assignment rules, you might encounter the “Bad Assignment” errors.

In this tutorial, we will walk you through these rules, why they are there, how they work, and what violations cause this error.

What Is a “Bad Assignment” Error in ZSH?

In ZSH the “Bad Assignment” error occurs when you attempt to assign a value to a value in a format that violates the ZSH syntax rules.

You can think of it as a way of ZSH telling you that the format you are using to set a variable is incorrect.

Let us now try to understand what causes this error and how you can correct them in your ZSH scripts.

Causes of the “Bad Assignment” Error

The following are some of the most common causes of this error when dealing with ZSH scripts:

1. Space around the Equals Sign

When building the ZSH scripts, you cannot have spaces around the equal sign when assigning a value to a given variable.

For example, the following script is incorrect:

var = "This is wrong!"

To fix this, remove the space as follows:

var="This is correct!"

2. Incorrect Variable Name

The second potential cause of this error is an incorrect variable name. You violate the variable naming rules when you fail to follow these:

The variable names must start with a letter or underscore.
The variable names can only contain letters, numbers, and underscores.
Avoid using special characters, spaces, or hyphens in variable names.

Hence, violating any of the given variable naming rule can lead to this error. An example is as follows:

1st="this is wrong"

In this case, the previous line returns an error since the variable names cannot start with a numerical value.

To fix this issue, ensure that your variable name adheres to the given rules.

Conclusion

In this tutorial, we explored about the ZSH “Bad Assignment” error, why it occurs, and how to fix it in your scripts.