Node.js fs.readdirSync() Method

In this article, we will discuss the Node.js fs.readdirSync() function with its syntax, parameters and examples.

What is the Node.js fs.readdirSync() function?

The Node.js fs.readdirSync() function concurrently reads the contents of a directory. The method returns an array of all the file and object names in the directory. Using option arguments, we can change how files are restored from the path.

This component, which is part of the Node.js fs (file system) module, provides a file system management interface similar to a traditional POSIX system. Note that using the readdirSync() function to access directory data pauses code execution synchronously until the contents of the directory are completely read.

An array of filenames contained in a directory is returned by fs.readdirSync() when it receives a path to a directory as input. The name of a file or subfolder within the designated directory is represented by each filename, which is a string. The filenames in the array may not appear in the same order on different systems or during multiple program runs.

Syntax:

It has the following syntax:

Parameters:

The two parameters listed above and explained below are accepted by this method:

• path: It contains the directory path from which the items must be viewed. It may be a URL, String, or Buffer.
• options: This object allows us to set optional arguments that will change how the function operates.

Two parameters are optional:

• encoding: The string value indicates the encoding that should be applied to the filenames given as part of the callback argument. 'utf8' is the default setting.
• withFileTypes: It is a boolean value that indicates whether or not fs. Dirent objects will be returned for the files. False is the default setting.

Returns:

The files in the directory are contained in an array of String, Buffer, or fs.Dirent objects.

The synchronous nature of readdirSync() means that it will stop executing more code in the application until the directory runs out. It is an important point to keep in mind. It can cause our program to fail in some cases, especially where performance is important or when working with large directories.

Key Points of the fs.readdirSync() Function:

Several key points of the fs.readdirSync() function in Node.js are as follows:

• Synchronous Nature: The synchronous nature of the readdirSync() function prevents the execution of new code until the directory is completely read, unlike its asynchronous sibling fs. readdir().
• Directory path: We only need to provide the path to that directory as its parameter. This approach can take an absolute or relative form.
• Error handling: The try-catch block should be used to deal with potential errors in discarding method calls if an error occurs (for example, a directory does not exist or the user is not authorized to read).

Pseudocode:

1. Import the fs module.
2. Try to read the directory synchronously using fs.readdirSync().
3. If successful, loop through the array of filenames and perform desired operations.
4. If an error occurs, catch the error and handle it appropriately.

Program 1:

Let us take an example to illustrate the fs.readdirSync() function in Node.js.

Output:

Program 2:

Let us take another example to illustrate the fs.readdirSync() function in Node.js.

Output:

Explanation:

In this example, the fs.readdirSync() function may throw an error if no directory exists or there is a problem reading the directory, so it is important to fix the problem when using the function in the previous example, every possible error is caught and is sent to the console with the effort...the catch block.

Conclusion:

In conclusion, the contents of a directory in Node.js can be read simultaneously using the fs.readdirSync() function. Despite its ease of use, the consequences and performance implications must be considered, especially when working with large directories or for business-critical applications.